Category: Coffee Roasters

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Coffee review Coffee Roasters Observations Science history slow Tea

HR Higgins, Duke Street

Interior of HR Higgins cafe
The view of H.R. Higgins (Coffee-man) from Duke Street. The Royal Warrant can be seen on the side of the wall.

Established over 80 years ago, HR Higgins in Mayfair’s Duke Street is somewhat of an institution. From the pavement, you can look into the cafe space in the basement below while the shop upstairs offers coffee beans and tea for retail. During the (earlier) mornings, coffee is also prepared for take-away at the entrance to the shop on the ground floor while the cafe downstairs is closed.

The first time I came here, it was only to buy beans. That time I tried the Rwandan Women’s cooperative coffee and was impressed by the scales used to weigh out my 250g: a proper mechanical scale set complete with weights. The second time I tried it, again I only had time to purchase beans but I determined that the next time I would definitely try the cafe downstairs because if there was so much physics to appreciate upstairs with the scales and the decor, how much more would there be downstairs. And so, I arrived one morning at 8.30am having checked the opening hours and the cafe downstairs was… closed. It turns out that although the shop is open, and although take-away coffee is served from the front of the shop, the cafe only opens much later at 10am (on weekdays).

Inside an empty cafe.
Inside an empty cafe, downstairs at Higgins. The clock on the wall is a throw back to the ’70s while the mosaic tiling on the floor is particularly mesmerising. What strikes you?

However, what was an initial disappointment turned into a great opportunity as I was able to have a proper look around, completely on my own, while the man upstairs prepared my V60. Having no intention of actually ‘taking-away’ the take-away, when I came back upstairs (and had another look at the scales and tins of coffee at the back of the store) I went outside to the “H.R.Higgins” bench to sit and enjoy my coffee and the surroundings. There were a few pastries that were also available for take-away but this time I just took my coffee and sat down.

The coffee was really good. I had been given a choice of two coffees for the V60 and went for the Honduran as it was recommended as being particularly good for the V60 brew method. It was packed with flavour notes and character as it cooled while I sat on the bench. The bench offered a view of city life. The busy cafe next-door to my left; the old sign “Duke Street, W”* on the wall opposite; the imposing “Brown Hart Gardens” which is above an early 2oth century electrical substation just to my right and of course, the cafe itself in the basement visible behind me. The bench was also a good spot for people watching. Many people, with many characters, walked past (or got their coffee in Higgins and then walked past). I thought perhaps that I even saw George Osborne** wandering by but decided to let my mind wander to think about the physics instead.

Of course there was a lot to ponder. The nature of scales and the definition of the kilogram had been an obvious starting point but the reflection of the cafe name in the window opposite me provided further directions of thought. The patterns of the tiling in the cafe could provide several avenues of thinking while the history involved with the establishment of this establishment would have prompted a significant diversion. Finally, the antique bike standing next to the bench took me on the thought-journey that occupied the rest of the time I spent on the bench and enabled me to keep my phone left solely for taking photographs.

An old bike with flowers where a delivery box used to be.
The H.R. Higgins bike. Complete with Brookes saddle and flowers for luggage, this bike gave plenty to ponder while enjoying a coffee.

Now used as a flower pot holder, this old bike looked as if it had been adapted from a delivery bicycle of a fair few years ago. The brakes were immediately attention grabbing. We have become used to the wires used to operate the brakes on modern bikes but these used firm metal rods to transfer the action on the brake levers on the handle bars down to the wheels. And then the wheels themselves had rubber tyres. Again, this is somewhat obvious and very familiar except the first bikes had iron wheels because rubber tyres had to be invented.

There is a potential diversion here to the story of rubber, which could almost be a cafe-chemistry review but we won’t go that way today. Nonetheless, it is worth pondering that rubber tyres are, just like coffee, a product with a varied history of globalisation, trade and colonisation. What enabled the bicycle wheel to evolve from cast iron to pneumatic tyres was the chemistry involved in the ‘vulcanization’ process invented by Goodyear that meant that the rubber no longer suffered from getting too soft at higher temperatures and too hard at lower temperatures. Anyway, that’s a digression.

Returning to the bicycle, a lot of physics is involved in cycling. Is it actually clear how any of us can balance on a bicycle? A short answer, and the one that is often off-handedly given, is that we can cycle because of “conservation of angular momentum”, but it turns out that it is a little more tricky than just that. A few years ago, a chemist decided to test the ideas put forward to explain how we balanced on a bicycle by building so-called “un-ridable” bicycles and found that he could actually ride some of them, thereby showing that some of our ideas on bicycle riding needed a little ‘tweaking’. The basic ideas of conservation of angular momentum were correct, but like many things, if you actually want to understand it, you need to go a bit deeper (and do a couple of experiments!).

As we move beyond the basic physics so we move to the technology of cycling and the improvements that are being made to competitive cycles (and their riders) to make them more aerodynamic. We have moved a long way from brakes using rods and delivery cycles. And yet, sometimes there are advantages to the old ways. Just as the scales at H.R. Higgins still work perfectly well with the balance and weights system, so new delivery bicycles are re-appearing in London, swapping polluting vans for cleaner-greener delivery vehicles. Just these ones no longer have metal rods for brakes and they perhaps have a pedal-assist electric motor.

Have you enjoyed a coffee at H.R. Higgins (or somewhere similar)? What did you notice that enabled you to put your mobile phone down and really think about your surroundings? Do let me know in the comments section here or via social media.

H. R. Higgins is at 79 Duke Street, Mayfair, W1K 5AS

*The single “W” on the sign (rather than the post code of the area “W1”) shows that the sign has been there since before the first World War when the London post code system was refined from the merely “W” to the W1, W2 etc. that we use now.

**George Osborne was the Chancellor of the Exchequer (finance minister for the UK government) from 2010 to 2016.

Categories
Coffee review Coffee Roasters Observations slow Uncategorized

In search of origins

Amaje coffee
Buriso Amaje Coffee from Ethiopia via Amoret Coffee in Notting Hill. The Jimma 74158 and 74160 varietals are selections from coffee grown in the wild.

It was a goat herder named Kaldi, so the story goes, who first noticed the effect of coffee beans on the the energy levels of his goats. After telling the local abbot of his observations, the monks at the nearby monastery realised that this drink could help them stay awake during prayer and so the reputation, and consumption, of coffee spread from Ethiopia and then throughout the world.

While the details may be questionable, there is evidence that the coffee plant originated in Ethiopia. Coffee still grows wild in parts of Ethiopia and the oldest varietals are also to be found there. And so, when I realised that my latest coffee was an Ethiopian Natural of varietal Jimma 74158 and 74160, roasted by Amoret coffee in Notting Hill, I thought, why not do a coffee-physics review rather than a cafe-physics review? For there are always surprising links to physics when you stop to think about them, whether you are in a cafe or sampling a new bag of beans.

This particular coffee was grown by Buriso Amaje in the Bensa District of the Sidama region of Ethiopia. The varietals were selections from the Jimma Research Centre from wild plants that showed resistance to coffee berry disease and were also high yielding. Grown at an altitude of 2050m, the naturally processed coffee came with tasting notes of “Blueberry muffin, white chocolate” and “rose petal” among others. Brewed through a V60, it is immediately clear it is a naturally processed coffee, the complex aroma of a rich natural released with the bloom. Indeed, the bloom was fantastically lively with the grounds rising up with the gas escaping beneath them in a manner reminiscent of bubbling porridge (but much more aromatic). And while I lack the evocative vocabulary of Amoret’s tasting notes, the fruity and sweet notes were obvious, with blueberry a clear descriptive term while I would also go for jasmine and a slight molasses taste. A lovely coffee.

Brewing it again with an Aeropress, the tasting notes were different. We could start to ponder how the brew method affects the flavour profile. But then we could go further, how would this coffee taste if brewed using the Ethiopian coffee ceremony? Which leads to further questions about altogether different origins. Where did this come from and how do our methods of experiencing something emphasise some aspects while reducing others? Ethiopia offers a rich thought current if we consider how things originated because it is not just known for its coffee, Ethiopia is also home to some of the world’s oldest gold mines. Today, one of the larger gold mines in Ethiopia lies just to the North West of where this coffee came from, while a similar distance to the south east is a region rich in tantalum and niobium. We need tantalum for the capacitors used in our electronic devices. In fact, there is most likely tantalum in the device you are using to read this. While niobium is used to strengthen steel and other materials as well as in the superconductors within MRI machines. Where do these materials come from?

The Crab Nebula is what remains of a supernova observed in 1054AD. Explosions like these are the source of elements such as iron. Image courtesy of Bill Schoening/NOAO/AURA/NSF

Within the coffee industry there has been a lot of work done to demonstrate the traceability of the coffee we drink. But we know much less about the elements that form the components of many of the electronic devices that we use every day. And while this leads us into many ethical issues (for example here, here and here), it can also prompt us to consider the question even more fundamentally: where does gold come from? Indeed, where do the elements such as carbon and oxygen that make coffee, ultimately, come from?

The lighter elements, (hydrogen, helium, lithium and some beryllium) are thought to have been made during the Big Bang at the start of our Universe. While elements up to iron, including the carbon that would be found in coffee, have been formed during nuclear fusion reactions within stars (with the more massive stars generating the heavier elements). Elements heavier than iron though cannot be generated through the nuclear fusion reactions within stars and so will have been formed during some form of catastrophic event such as a stellar explosion, a supernova. But there has recently been some discussion about exactly how the elements heavier than iron formed, elements such as the gold, tantalum and niobium mined in Ethiopia.

One theory is that these elements formed in the energies generated when two neutron stars (a type of super-dense and massive star) collide. So when the LIGO detector, detected gravitational waves that were the signature of a neutron star collision, many telescopes were immediately turned to the region of space from which the collision had been detected. What elements were being generated in the aftermath of the collision? Developing a model for the way that the elements formed in such collisions, a group of astronomers concluded that, neutron star collisions could account for practically all of these heavier elements in certain regions of space. But then, a second group of astronomers calculated how long it would take for neutron stars to collide which led to a problem: massive neutron stars take ages to form and don’t collide very often, could they really have happened often enough that we have the elements we see around us now? There is a third possibility, could it be that some of these elements have been formed in a type of supernova explosion that has been postulated but never yet observed? The discussion goes on.

coffee cup Populus
Where did it all come from? Plenty to ponder in the physics of coffee.

The upshot of this is that while we have an idea about the origin of the elements in that they are the result of the violent death of stars, we are a bit unclear about the exact details. Similarly to the story of Kaldi the goat herder and the origins of coffee, we have a good idea but have to fill in the bits that are missing (a slightly bigger problem for the coffee legend). None of this should stop us enjoying our brew though. What could be better than to sip and savour the coffee slowly while pondering the meaning, or origin, of life, the universe and everything? That is surely something that people have done throughout the ages, irrespective of the brew method that we use.

As cafes remain closed, this represents the beginning of a series of coffee-physics reviews. If you find a coffee with a particular physics connection, or are intrigued about what a connection could be, please do share it, either here in the comments section, on Twitter or on Facebook.

Categories
Coffee Roasters General Sustainability/environmental

Packaging, all about substance

The OK Vincotte or OK Compost HOME labels are for items that are suitable for “home” composting. This label was on a coffee bag from Amoret Coffee

Who would have thought that buying coffee to drink at home could be such a moral minefield? There are issues of sustainability: for the people involved in the coffee process through to the planet. Issues of transportation and the balance between supporting local independents or larger companies with different sustainability policies. And in amongst all this are issues of packaging the final product. How does your freshly roasted coffee arrive? Is it in a bag that you have no choice but to dispose of in the ordinary rubbish, or in a bag (or even bottle) that can be re-used and recycled or composted?

As many of us are buying more coffee on-line at the moment, I thought that it may be helpful to have a list of roasters who have gone to some effort in thinking about the sustainability of their final packaging. Of course many other issues are involved in your decision about which coffee to purchase. This list is only intended as a place to collate information on coffee bean packaging. The list is not definitive, so if you know of a roaster (or if you are a roaster) who is not currently featured on this list but you think ought to be, please let me know as I will be updating the page regularly. Similarly if you notice a mistake, please get in touch (e-mail, Twitter, Facebook).

One more caveat. We each need to decide what we consider a ‘good’, or sustainable packaging. The issue is highly complex. Some of us will have the ability to compost at home, some will have access to an industrial composting bin, some will go to supermarkets regularly and would prefer to recycle plastic together with other plastic bags. And then of course there is the problem that packaging is just one part of a whole relationship between farmer, supplier, roaster, customer and planet. It requires thought and consideration on our part as consumers, on the part of the coffee roasters and, I think, it requires kindness on all our parts, appreciating the efforts of those who are trying to improve things while recognising that there is currently no perfect solution.

In alphabetical order:

Compostable (Home)

Very few items marked “compostable” are, in reality, “home” compostable. Properly home compostable items are certified by the “Ok Compost, Vincotte“/OK compost-HOME labels.

Amoret – Notting Hill, London and online. Coffees (including directly traded coffees) are supplied in bags certified as home compostable (OK Compost). Owing to supply problems during the pandemic, some bags of coffee have been packaged in EN13432 (industrially) compostable bags instead but a recent addition of a new supplier should hopefully solve these supply problems.

Coromandel Coast – online. Shade grown coffee from India, coffee orders online come in a Natureflex bag within a recyclable cardboard box. Natureflex is certified as ASTM D6400 but also listed as “home” compostable and indeed composted in my worm bin composter in 17 weeks (packaging was from Roasting House in that instance).

Roasting House – online. Delivery by bike in the Nottingham area. Ground coffee is supplied in home compostable packaging. Whole beans are supplied in recycled and recyclable bags (see below). You can read more about their latest packaging policies here.

Compostable (Industrial)/Biodegradable

Most packaging that is marked compostable (or biodegradable), but that is not marked as home compostable, will require specialist facilities to compost/degrade such as industrial composting. Compostable items should be certified by (BS) EN 13432 and/or ASTM D6400.

Coromandel Coast – Croydon and online. Bags of coffee purchased in Filtr, the coffee shop associated with Coromandel Coast in Croydon, are supplied in industrially compostable packaging. For coffee purchased online see above.

Dear Green – Glasgow and online. “Together we can all make a difference”. Next year, COP26 will go to Glasgow and Dear Green are ready, organising the 2018 Glasgow Coffee festival to be re-usable cup only. Coffee is supplied in biodegradable packaging.

Glen Lyon Coffee – Perthshire and online. Glen Lyon coffee made a commitment to zero waste in 2017 and use OK Compost Industrial certified coffee bags for their 250g and 500g packaging. 1kg bags are designed to compost within 3 months in a home composting environment. They offer a ‘drop box’ for customers to return their bags for composting. You can read further details about their dedication to sustainability here.

Recyclable

Several roasters have opted for recyclable packaging and quite a few are using the Dutch Coffee Pack bags which are additionally carbon neutral (via offsetting which you can read about here). Be careful with the “recyclable” label as it may, or may not, be suitable for collection with your household waste. Look for the recycling labels on the bags. PET plastic (label 1) is often collected with the street based collections but LDPE (label 4) should be taken to a supermarket where they provide recycling for plastic bags.

Atkinsons – Lancaster, Manchester and online – Established in 1837 as a tea merchant in Lancaster, Atkinsons now sell tea and coffee using recyclable packaging which is also carbon neutral.

Casa Espresso – online – Great Taste award winner for 3 years in a row, coffee is supplied in recyclable and carbon neutral packaging.

Chipp Coffee – online – In addition to using recyclable packaging, you can read more about the ethical and sustainability policies of Chipp Coffee here.

Fried Hats – Amsterdam and online – recyclable but also re-usable. The coffee comes in bottles that can be re-used before ultimately being recycled.

Good Coffee Cartel – online – Coffee in a can, but this time a re-usable and recyclable can containing speciality coffee beans.

Manumit coffee – online – “Manumit”, a historical verb meaning to set a slave free. Manumit coffee works with people who have been subject to exploitation and modern slavery so that they can rebuild their lives. Their coffee comes in recyclable and carbon neutral, Dutch Coffee Pack packaging

New Ground – Oxford, Selfridges and online. Providing opportunities for ex-offenders to develop new skills and employment, coffee is provided in recyclable packaging.

Paddy and Scotts Suffolk based, various outlets and online – Coffee packaging is described as PET recyclable or compostable. Check labelling on package. More info here.

Rave Coffee – Cirencester and online – Rave coffee have been conscientious in describing the reasoning behind their policy of using recyclable (LDPE (4)) bags, You can read about the rationale here.

Roasting House – For whole beans, Roasting House supply the coffee in (recycled and) recyclable paper packaging. Ground coffee is supplied in home compostable packaging (see composting section).

Runnerbean Coffee – Berkshire based Runnerbean coffee uses recyclable (LDPE label 4) coffee bags and, additionally runs a tree planting scheme to offset their carbon footprint. They had been using compostable bags until recent supply problems, check their website for the latest details.

Steampunk coffee – online. I’m reliably informed that their coffee is supplied in recyclable packaging but have been unable to confirm.

This list will be updated regularly. Please do get in touch if you would like to suggest a coffee roasting company who should be included: email, Twitter, Facebook.

Categories
Coffee Roasters Observations

An effective medium for coffee roasting?

Pulp, Papa Palheta KL
Electrical boxes in Pulp by Papa Palheta KL. The moisture meter at Amoret is much smaller than these old boxes at this ex-printing works.

coffee bowl pour over
How would you measure the moisture content of a coffee bean?

Recently I had the pleasure of a tour of Amoret coffee in Notting Hill. In addition to discussing an upcoming event that Amoret are kindly hosting (an evening of coffee physics, sign up to the events list to find out more), it was great to see the coffee roaster that is installed there. Fascinating, with what looks to be a really interesting series of coffees lined up ready to roast. And in the course of all this, we came upon the moisture meter, which got me thinking.

Measuring the water content of green (and then roasted) coffee beans is quite critical to gaining an understanding of your roasting process apparently. Sitting on the shelf next to the roaster at Amoret, a small box contained an instrument designed for measuring exactly this. Although it looks as if it is a giant ice cream scoop with a central pillar in the middle, it is actually designed to measure the water content of the coffee beans capacitively. How does it work and, knowing how it works, can we make any predictions as to anomalous results that it may occasionally provide?

The simplest style of capacitor consists of two metallic plates with a gap between them. The capacitance changes depending on the size of the metallic plates, the distance between them and, crucially for this subject, the material that fills the space between the plates. When you apply an electric field between the two plates, the electric moments of the material within the capacitor will tend to align with the electric field. Different materials will react differently depending on their “polarisability”. You only have to think about how a stream of water reacts to a statically charged balloon to see why.

Pulp, Papa Palheta KL
Electrical boxes in Pulp by Papa Palheta KL. The moisture meter at Amoret is much smaller than these old boxes at this ex-printing works.

What this means in practise is that a capacitor formed of plates filled with water will have a different capacitance to the same capacitor filled with air. We say that the ‘permittivity’ of the air is different from the ‘permittivity’ of the water. Measuring the capacitance tells us the permittivity of the material between the plates and so whether the capacitor is filled with air or water. Now fairly obviously, it’s not quite as simple as this because a coffee bean is neither air nor fully water and the moisture meter is not two parallel plates. But in terms of the physics of the measurement, the shape doesn’t really matter here while another bit of physics called “effective medium” theory helps us with the fact that the bean is neither fully air nor fully water. Effective medium theory tells us that the relative permittivity of the mixture is simply proportional to the sum of the individual contributions from the polarisability of each set of molecules. So, merely changing the number of water molecules between the plates will change the capacitance. By knowing what the contribution of the dry beans are, we can calculate the moisture content of the coffee beans as a percentage. Or at least, the instrument can do this calculation internally and provide you with a number on the display.

But. This is what got me thinking about the measurements of the coffee at Amoret. Coffee beans come in a range of sizes and shapes, as you can see by taking a look at the online selection at Amoret (here). Some of these coffees are small, tending towards a more spherical shape while some are significantly larger and more conventionally bean shaped. Is it obvious that the moisture content measured for different coffees is directly comparable? This is not to diminish the use of the moisture meter. As a comparative tool to measure before and after roasting for example, it should be a fairly good indicator. But what should we expect for the absolute accuracy of the instrument? Is a 16% moisture content measured in a small bean really equal to a 16% moisture content measured in a big bean?

At first sight it may seem a silly question, after all, the moisture content is expressed as a percentage; why should size matter? But perhaps we could have a little further think about this. The moisture meter will be optimised for a dense packing of coffee beans. So if we filled it with small beans such that there were very few air gaps between the beans, we would expect a fairly accurate moisture content measurement. If on the other hand, the beans were larger such that there were quite a lot of air gaps between the beans, the actual volume fraction of water molecules in the meter would be reduced (16% of 100% full is greater than 16% of 90% full). And as the capacitance is directly related to the number of water molecules in the sample, the water content that was measured would be less than the true value in each individual bean. So this leads to my first question for roasters using capacitive moisture meters:

  • Do your large beans, that don’t pack well into the moisture meter, often show lower moisture contents than your smaller beans?

variables grind size, pour rate, pour vorticity
Coffee roasting is part-science, part-art and requires great skill and attention. But can thinking about a little extra physics help to understand some of what goes on with the process?

A second point is slightly more subtle. Consider that I had two beans of equal moisture content (%). But one of those beans packs more fully into the moisture meter than the other larger, more irregularly shaped bean. On roasting these beans, they both lost the same volume fraction of water so, say, they went from 16% to 12% water content on roasting. Would both beans show that they had lost the same amount of water?

We could start by thinking about packing these beans into the meter. The one that was densely packed would show a moisture content that was close to the real value (in our example 16%).  The one that was less densely packed however would have a lower volume fraction of water and so show a lower water content. If we assume that the beans filled 90% of the space, the percentage that we measure would be 16% of 90% = 14.4%. On roasting, the two beans are again loaded into the meter and again the densely packed one will show a moisture content close to the real value (in our example 12%). The loosely packed one will show a moisture reading of 12% of 90% of the volume which is 10.8%. Crucially, if we are looking at moisture difference, the densely packed bean will appear to have lost more water (16% – 12% = 4%) than the loosely packed bean (14.4% – 10.8% = 3.6%). Which leads to my second question for roasters:

  • Do small beans that pack well into the moisture meter appear to lose more water for an optimised roasting profile than your larger, less densely packed beans?

Clearly, different beans will have different moisture contents anyway and so it may be difficult to discern any pattern between two specific coffees. The moisture readings may genuinely reflect the fact that the smaller beans have higher water content or vice versa. And also obviously, the measured moisture content is only one part of determining a successful roast profile. However the question is one of statistics. On average, do your larger, less well packed beans have a moisture level lower than you expect? And on average, do they seem to lose less water (measured capacitively) on roasting?

I’d be fascinated to hear your thoughts, here, on Twitter or Facebook.

Categories
Coffee review Coffee Roasters Observations

Connectivity at Populus, Singapore

Inside Populus
The cool interior of Populus

A friend recommended that we try a café in her neighbourhood near Outram, in Singapore. So, with some time to spare we walked up the hill and into the welcoming air conditioning of The Populus Cafe in Neil Road. The coffee is roasted by 2º North and there is an extensive menu of both coffee based drinks and a seasonal filter selection. There was also a range of iced drinks on the menu which in the Singapore heat were tempting, but I opted for the 6oz Long Black. Given more time, or a second visit, I would certainly try the filter, but this time an appointment across the island was calling. There seemed too to be a very good lunch selection on the menu, but again, the lunch appointment elsewhere meant that it was just the 6oz long black that day.

It should be possible to take some time back from a busy schedule full of appointments and concerns and sit back and ponder the connections in any café. Having run from one set of concerns and soon to have to go off to another, would this be possible in 30ºC+ heat? The comfortable space of Populus provided a perfect place to test this question. Sitting back while sipping my coffee, the first thing that struck me was the wood, arranged in different geometrical patterns on the walls. The floors too were decorated with hexagonal stone tiles while the door was glass. There was a different pattern on the door, but what was it? Staring at it for a while, I thought about the schematics you sometimes see for a connected world, each of us a point connected to the others (how true is it that we are all 6 hand shakes away from everyone else?). Maybe this fitted with the name of the café? My companion in these reviews instead thought of crystals and the way that crystal structures are represented with lines between the atoms. While loading the photograph of the door onto the website, I saw a pattern of flowers. It seems that the pattern on the door formed and reformed with each new view.

door, Populus
Looking through the door of Populus. What patterns do you see?

Then there was the cup. A black coffee in a black cup, with umbral and penumbral shadows (as pointed out by @Bob_MatPhys on Twitter). A few years ago there was great excitement about a new material that had been made to be blacker than any known material. The substance used a coating of carbon nanowires (of just 20nm diameter which is about 1/1000 the size of a grain of espresso grind) to absorb light across the visible, ultra-violet and infrared spectrum. And just as nano-structuring a material helps it to appear the ‘blackest’ object ever, so changing the structure of a material can make it invisible to other parts of the electromagnetic spectrum such as microwaves. Quite why various defence companies and governments would invest so much into this research I will leave for your imagination (it is not to avoid heating soup). A more peaceful and beautiful side of the effect of nanostructure on optical properties is the way that the feathers of a peacock have a striking green-blue hue. It is another example of light interacting with a structure and so producing different optical effects; all is not as it appears.

coffee cup Populus
A black coffee in a black coffee cup. But what does black mean? And is something that is transparent always so?

And the fact that all is not as it appears gives another connection to the Populus cup. For although it seemed quite black to my eyes, it was clearly shining in the infra-red. The hot coffee inside was radiating through the cup and onto my hands. Which could prompt us to consider what ‘black’ really means? And for that matter, what about transparent? Just as ‘black’ only absorbs light over a certain set of frequencies, so transparent only lets light through over certain frequencies. The door that we can see through with our eyes may be opaque to a different frequency range that we cannot see. Just over two hundred years ago Carl Wilhelm Scheele deduced the presence of the infrared by contemplating how his stove heated him in the winter. Although he could not see them, the ‘heat rays’ seemed to come straight towards him and yet did not cause a candle flame to flicker, clearly the heat was ‘radiating’ like light rather than travelling like a breeze on the air.

The knowledge that structure, as well as pigment, provides the colour to our world, or that what is transparent at some frequencies may be opaque to others, these things give us plenty to think about, scientifically and perhaps more philosophically, while enjoying our black coffee. Which shows that even ten minutes spent sitting with your coffee can result in a series of thought connections that you may not have enjoyed had you rushed from appointment to appointment while checking your smartphone. That we could all enjoy a good ten minutes (or more) in the Populus Cafe!

The Populus Cafe is at 146 Neil Road, Singapore 088875

Categories
Coffee review Coffee Roasters Observations Science history slow Sustainability/environmental

A Story with many layers, Clapham Junction

Story Coffee St John's Hill Clapham
The doorway to Story, or a story depending on how you look at it.

A “ghost sign” above the door to Story Coffee on St John’s Hill ensures that you know that you have arrived at the correct place. “Peterkin Custard, Self-Raising Flour – Corn Flour, can be obtained here”, only now it is coffee rather than custard that is sold in the shop beneath. The sign is an indicator to the many tales that could be discerned while exploring the coffee within. I had had a couple of attempts to visit Story Coffee (thwarted for a variety of reasons) before Brian’s Coffee Spot’s review appeared a couple of days after one of my attempted visits. Suitably re-motivated, another trip was attempted (address checked, closing times checked) and this time we were in luck. Although a pour over is listed on the menu, sadly this was not available on our visit and so I enjoyed a lovely long black instead (Red Brick, Square Mile) while looking at the cakes on offer. There was plenty of seating in which to shelter from the rain outside and many things to notice in this friendly café. In addition to the cakes and lunch menu, a box on the counter housed “eat grub” protein bars, protein bars made of cricket powder. Are insects the future for humans to eat protein sustainably?

glass jar at Story
Through a glass darkly?
The distortions produced by the refractive indices of air, water and glass and the shape of the glass produces interesting effects on our view through it.

The tables were well arranged for people to sit chatting while enjoying their beverages and it is always an excellent thing (from a personal point of view) to encounter a café with a no laptop (or tablet) at the tables policy. Complementary tap water was available in jugs placed on each table while it was also nice to note that Story branded re-usable cups were on sale from the counter. Many things we noted can be seen in the gallery pictures in the review on Brian’s Coffee Spot: the funky fans, the egg shaped light shades, the light introduced by the large glass window panes (though it was a much fairer day on Brian’s visit than on ours). Each had its contribution to a thought train, the way the glass water jar bent the light coming through, the concept of a Prandtl boundary layer in fluids (and its connection to both fans and coffee cups). Moreover there were hexagons, which for someone who has worked on the periphery of the graphene craze, are always thought provoking.

Apart from hexagons decorating the top of the stools, there were hexagons lining the counter made of cut logs, each showing the rings from the tree that was felled. Rather than a flat surface, these hexagons were made to be different thicknesses on the wall, rather like the hexagonal columns of the Giant’s Causeway. It is a subtle thing that may have implications for the space that is otherwise surrounded by flat, solid, walls. Such spaces can become echo-y and yet, the music and conversation in Story was not overly distracting presumably because features such as the uneven hexagonal wall reflected the sound waves such that they destructively interfered rather than echoed around the room.

every tree tells a story, but which story
A macroscopic crystal of hexagonally cut logs forms the side of the counter.

Each log in the hexagonal decoration was cut with its cross-section showing a number of tree rings. We know that we can age a tree by counting the rings (though each of these would be underestimated as they have been trimmed into hexagons post-drying), but what more do the tree rings, and the trees themselves have to tell us? The rings are caused by the rapid growth of large cells during spring followed by a slower growth of smaller cells as the year progresses. But this method of growth means that the cut logs have more to tell us than just their age. The spacing between the rings can tell of the weather the tree experienced during that year, were there many years of drought for example? Such clues, from the relative density of the tree rings, can help researchers learn about the climate in previous centuries, but conversely, reading the climate report in the rings can indicate in which year a tree was felled and so the age of a building for example.

coffee at Story
Many stories start with a coffee.

And then there is more, trees will grow at an average rate per year so that, as a rough guide, the circumference of a mature (but not old) tree increases by 2.5cm per year¹. There is therefore something in the idea that you can have a good guess at how old a tree is by hugging it. But this assumes that the tree is growing in its optimum conditions, far enough from any neighbouring trees so as not to be crowded into growing more slowly. So the absolute density of tree rings must also give a clue as to whether this tree was in a dense forest or an open clearing. Which is reminiscent of something else that living trees can tell you if you listen to them closely enough: trees will grow so that their leaves are exposed to the maximum amount of light. For us in the UK, this means that the crown of a tree will frequently tip towards the south (where the Sun is most often) and there will be more leaf growth (and consequently more branches) in a southerly direction². But again, we only see this if the tree has room to grow on its own, without the crowding, and competition, of too many neighbours. A solitary tree helps us to know which direction we are walking in.

empty coffee cup Story St John's Hill
While many coffees could also tell a story. It depends on how you read them.

Which all points to the idea that there are many stories being told all around us all of the time, the ones we hear depend on what we choose to pay attention to. So what about the story behind the ghost sign above the door? The Peterkin custard company was a venture by J. Arthur Rank in an attempt to start a milling company in the mould of his father’s (Rank Hovis McDougall, later bought by Premier Foods). The company failed and Rank went on to form the Rank Organisation that was responsible for many films made throughout the 40s and 50s as well as running a chain of cinemas around the UK. Truly a sign concealing many stories.

 

Story Coffee is at 115 St John’s Hill, SW11 1SZ

¹Collins complete guide to British Trees, Collins, 2007

²The Walker’s Guide to Outdoor Clues and Signs, Tristan Gooley, Hodder and Stoughton, 2014

 

 

 

 

Categories
Coffee Roasters General Observations

As quick as (a) Quarter Horse

Dog and Hat, Dog & Hat, Hundred House, Quarterhouse coffee
The package from Dog & Hat with Hundred House and Quarter Horse. Is it a particularly contemplative dog with the monocle?

Links with science can be found everywhere, from the café to the coffee roaster. A couple of weeks ago a delivery from Dog and Hat coffee gave me an opportunity to explore the random thought paths that may occur if you stop to ponder your coffee at home rather than in a café. The first coffee, an Ethiopian from Hundred House prompted thoughts on star gazing. But the second coffee, a Mexican from Quarter Horse coffee was equally thought provoking.

Finding time to prepare a V60 and sit with the SCAA “flavor wheel” as a guide, I was rewarded with a sweet, well rounded and perfectly enjoyable brew. I found fruity notes of blueberry and cherry/pineapple though the tasting notes on the packaging say “green grape, toffee and cocoa”. Sadly I missed the cocoa but this offers a good excuse for another slow brew with the coffee wheel at hand.

Thinking about the name of the coffee, I started to consider how you could quarter a horse. Perhaps not a literal horse given the ethical considerations but rather an irregularly shaped volume. How would you divide, into equal portions, an irregularly shaped object such as a horse? It seemed related to the question of finding the shortest route between two locations, how would you calculate the best route to take from A to B? In the 1950s a computer scientist called Edsger Dijkstra (1930-2002) came up with an algorithm to calculate precisely this problem. Originally designed to show the shortest routes between 64 cities in the Netherlands, Dijkstra’s algorithm is now ubiquitous in our lives.

Quarter Horse but how would you
A close up of the Quarter Horse Coffee Bag.

One of the ways in which we have started to rely on such algorithms is in car GPS devices or even on our phones trying to navigate to our destinations. Or at least, many of us do. London taxi drivers however have been shown to have developed a different brain structure from the general population that means that, for them, Dijkstra’s algorithm may be unnecessary. A few years ago, a study compared brain scans of people who had been driving London’s “black cabs” for a number of years to those of us in the general population. A follow-up study followed three sets of people over several years. A control group of people in the general population and a second group of people who studied the “Knowledge”, the navigational test that London taxi drivers have to pass in order to become cabbies. The Knowledge tests the driver’s ability to recall tens of thousands of London’s streets and the prospective cabbie can be asked to navigate between two points anywhere within a 6 mile radius of Charing Cross. Typically it takes years to acquire the Knowledge and not everyone who starts on the Knowledge will pass (the pass rate is only about 50%). This means that this second group of people splits into two groups; those who studied and passed the Knowledge and those who studied but did not pass.

The studies proved illuminating. One particular part of the brain, the posterior hippocampus had a greater volume of “grey matter” (the brain processing cells) in taxi drivers who had studied, and passed, the Knowledge compared with the general population. Moreover, those that had been taxi drivers for longer, showed larger posterior hippocampi. The changes in the brain seemed to lead to the cabbies having not only better navigational ability than the general population but better memory for London based information. The study of the trainees moreover confirmed that these brain changes occurred as a result of learning the Knowledge, showing that our brains are adaptable and still able to develop well into adulthood. While the brains of all the study participants started off similarly, those that went on to pass the Knowledge had a larger posterior hippocampus than those who either didn’t study or studied but hadn’t passed. However it was not all good news for the cabbies. The growth of the posterior hippocampus seemed to occur at the expense of the anterior hippocampus in long serving taxi drivers (but not newly qualified ones). The improved memory for London based information shown by the taxi driving group was also accompanied by a poorer ability to learn other visual information/memory related tasks in those that passed the Knowledge compared to the general population.

taxi and motorcycle, London
London black cab drivers have been shown to have a larger volume of grey matter in the posterior hippocampus area of their brains, demonstrating that our brains remain adaptable well into adulthood.

Perhaps the ability of the cabbies to navigate quickly around London’s streets suggests a second connection with Quarter Horse. A Quarter Horse is a breed of horse that can sprint very quickly over short (less than a quarter of a mile) distances. Which goes faster, the cabbie with the Knowledge or us with our smartphones once we have plugged in our destination? We are reminded of the tale of the hare and the tortoise. But I think a different tale is more appropriate. A tale that in reality was only ever a snippet of an ancient saying but has been developed into tales by thinkers such as Isaiah Berlin and Ronald Dworkin.

“The fox knows many things but the hedgehog one important thing”.

What does this mean? It seems there is a connection here between coffee roasting and taxi drivers, between algorithms and personal development, between coffee science and writing about coffee science. Is this connection really there or is it a meaningless statement that leads us into blind alleys of coffee consideration? It may be time to stretch our brains, grow our grey matter a bit and contemplate. Am I a fox or a hedgehog and where do London cabbies and coffee roasters fit in?

Quarter Horse coffee is online at https://quarterhorsecoffee.com

You can find out more about the coffee subscription site Dog and Hat on their website https://dogandhat.co.uk

You can read more about the taxi driver study on the Wellcome Trust’s press release about it here.

Enjoy your coffee, have fun thinking, grow your grey matter.

 

 

Categories
Allergy friendly cafe with good nut knowledge Coffee review Coffee Roasters Observations Sustainability/environmental

Bee-ing positive at the Sugar Pot, Kennington

coffee and cake Kennington
Banana bread and coffee with a sugar pot in the background at Sugar Pot, Kennington

What is it that makes a great café? A space to slow down and think? Good coffee and cakes? A local business that forms part of its local community and gives back to that community in different ways? As I was looking around for a new café to try, I was reminded of Sugar Pot in Kennington. Their website suggested that it ticked all of these boxes and so I was eager to try it (so eager in fact that I didn’t note the opening times, they close at 3 on week-days which is a problem when you arrive at about 2.55). So a second attempt at trying Sugar Pot was arranged, this time safely before lunch. This time, in the morning, there were quite a few chairs and tables outside the café in a roped off area of the street. (We hadn’t noticed this on the first occasion we visited as they had all been piled up inside the shop by the time we arrived). Most of these tables were occupied indicating that it is clearly an attractive place for locals to meet and chat over coffee. Fortunately there were also a fair number of tables inside which suited us as a café often offers more to ponder inside than out (though outside offers a different perspective particularly for people watching).

Inside, each table has an individual character and one in particular offered several points to think about both in terms of physics and aesthetics (you will have to visit to understand). However, it was elsewhere that my attention was drawn that day. Coffee is roasted locally by Cable Bakery while the cakes are from John the Baker of the Kennington Bakery. Sugar Pot definitely gets a tick in the “allergy friendly” box because they answered confidently (and with required caveats about traces) my dreaded question “does it contain nuts?” So I was able to enjoy a lovely slice of banana bread with my coffee. Most of the usual espresso based drinks are available (but not listed on the menu) together with a French Press coffee for those who prefer a non-espresso brew.

Interior Sugar Pot, Kennington
Noticeboard, magazines and coffee counter at Sugar Pot in Kennington

The community feel of the café was immediately apparent with a notice board adjacent to the counter being packed with notices of different activities happening around the locality and within Kennington Park which is just opposite. Underneath the counter were books and magazines and an advert for volunteering with the local bee keeping and urban farming organisation Bee Urban. This is indeed another way that Sugar pot gets involved in its local community. The coffee grounds are donated to Bee Urban for use in their Kennington Park based composting facility. Bees of course have an Albert Einstein link with physics as he is alleged to have said

“If the bee disappeared off the surface of the globe, then man would have only four years of life left. No more bees, no more pollinators, no more plants, no more animals, no more man.”

I do not know if he really did say this but it is a sad reflection on our society that rather than address our environmental crimes we are researching pollinating with drones. However, it turns out the the bee has a much more exciting, almost shocking, link with physics and one that I only discovered thanks to the excellent book “Storm in a Teacup” by Helen Czerski¹. The bee is indeed a very positive creature.

ultra violet, bee, bumble bee
The world looks very different to a bee. Image © www.gardensafari.net

Whether or not they have a happy disposition, it seems that 94% of bees are, electrically speaking, positively charged². They pick up a static charge while flying through the air in a similar way to a balloon being rubbed on your hair. Flowers meanwhile have a negative charge meaning that in addition to colour, shape, scent and pattern, bees can recognise flowers by their electric fields. These fields in turn mean that pollen from the flower ‘jumps off’ and adheres to the bees fur before the bee has even landed, increasing the efficiency of the bee as a pollinator. But it turns out that there is much more to it. When the positive bee lands on the negative flower, there is a charge transfer that results in a change of the electric field around the flower for a duration of 100 seconds or so. By constructing artificial flowers held at different voltages containing either a sugar reward or a bitter centre, researchers at Bristol university found that bees could learn to recognise which ‘flowers’ contained the sugar and which were too bitter to be visited by sensing the electric field around the ‘flower’. It suggests that the changing electric field of real flowers provides a mechanism by which the bee can recognise if a flower has been recently visited by another bee and so been recently pollenated. This would mean that by ‘feeling’ the electric field of the flower, the bee may decide that it would be more rewarding to carry on to a differently charged flower. You can read more about the research in the paper here.

It seems to me that learning about how the bee senses its environment reveals even more about the amazing way that nature (and physics) works. And this offers a link back to Sugar Pot. On the shelf behind the counter back at Sugar Pot was a card that had the message “Keep safe, live to be”. What does it mean “live to be”? In the environmental encyclical Laudato Si’, Pope Francis urges everyone to slow down and notice things such as the bee commenting that “If someone has not learned to stop and admire something beautiful, we should not be surprised if he or she treats everything as an object to be used and abused without scruple.” He goes on “… when media and the digital world become omnipresent, their influence can stop people from learning how to live wisely, to think deeply and to love generously… True wisdom, as the fruit of self-examination, dialogue and generous encounter between persons, is not acquired by a mere accumulation of data...”³ Which is one reason that in order to be, we may want to come back and take a closer look at those bees. Taking time to experience our coffee in a relaxing space such as Sugar Pot and to watch and ponder as the bee uses senses of which we are barely aware can never be a waste of our time. Indeed, it is possible that our world may depend on it.

¹Storm in a Teacup, Helen Czerski, Transworld Publishers, 2016

² Clarke et al., “Detection and learning of Floral Electric Fields by Bumblebees”, Science, 340, 6128, 66 (2013).

³The passages quoted are from paragraphs 215 and 225 respectively of Laudato Si which can be read online.

Sugar Pot can be found at 248 Kennington Park Road, SE11 4DA

Categories
Allergy friendly cafe with good nut knowledge Coffee review Coffee Roasters Observations Science history Sustainability/environmental

Paradigm shifts at The Observatory, Marchmont St

lines on a table, parallax
An espresso using coffee from Redemption Roasters and a chocolate brownie. What more could you ask?

Many years ago, there was an aquatics shop on the site of what is now The Observatory, a combined photography gallery and coffee shop. Although there is plenty to see through this glass fronted café, you do not feel that you are in a goldfish bowl so much as that this is a space created for you to slow down and contemplate your surroundings. The large rooms and comfortably spaced tables do, of course, give the opportunity for people watching: when we visited, there were people working with their laptops on some tables while others were having business meetings. Then there are the photographs, currently (though only for a few more days), an exhibition of photographs from the 60s and 70s by John Bulmer.

The coffee is supplied by Redemption Roasters and I enjoyed a dark, toffee like espresso with a very good slice of a chocolate brownie (confidently nut free). Several types of milk are on offer for milk based coffee drinks as well as a selection of cold drinks, together with a wide variety of cakes. It is definitely a place to return to when in the area.

coffee the Observatory, TLR
Cakes on the counter at The Observatory. Note the twin lens reflex “camera” on the shelf behind the counter.

While waiting for my coffee, I noticed the grain of the wood in the table. Dark, almost parallel lines on a lighter wood. You can see it in the photograph. Looking around the café, such parallel lines were everywhere. Planks of wood lined the walls, vertical, parallel lines stretching up to the ceiling. In the room towards the back of the café, the ceiling also had parallel lines on it which, given I was viewing them from a distance, appeared to converge with the effect of perspective. It is difficult to know whether these effects were deliberate in a gallery/café so dedicated to an exploration of the visual but I like to think that the small twin lens reflex camera on a shelf (which sadly turned out to be a pencil sharpener on sale) was a nod to this idea shifting lines of sight and perspective.

By definition, two parallel lines are lines that will never meet, no matter how far the lines are extended. If they were to meet at any point, they would not be parallel. This offers a way of measuring the distance to stars as well as providing food for thought on our way of seeing our place in the universe. The idea is that of parallax. If you were to measure the relative position of a star against the background of stars at midnight in June, and then go back to measure the same star relative to the same background at midnight six months later in December, you may find that the star seemed to have moved. The amount it moves, its parallax, is determined by how close the star is to the earth (have a look at the diagram).

parallax and coffee
As the point of view moves around the Sun (represented here by a V60), the closest coffee bean appears to shift relative to the background coffee beans.
The lower two diagrams are an attempt to see things from the perspective of the Lego person separated by “6 months” distance.

Take as an example the star Sirius. Located relatively close to us at a mere 8.6 light year distance, Sirius has a parallax of 0.38 arc seconds or, equivalently, about 0.0002 of the angular diameter of the moon viewed from Earth¹. Stars that are further away are going to have an even smaller parallax until the parallax becomes so small as to be difficult to measure. Even for nearby stars such as Sirius, the small size of the effect meant that it wasn’t until 1838 that it was first measured. Which may be part of the reason that the theory of Aristarchus (310-230BCE) never caught on when it was proposed.

Aristarchus was an early proponent of the idea that the Earth went around the Sun (and not the other way around). The Greek’s realised that if Aristarchus was correct, there should be a parallax effect for the stars viewed at different times of the year (every 3 months)¹. Unfortunately, the Greeks also considered that the stars belonged to a thin shell, so effectively all the stars were at the same distance from the Earth. Consequently, the parallax effect that they looked for (if Aristarchus was correct) was for two stars on that shell to move first towards then away from each other as the Earth circled the Sun¹. They never observed this effect and so considered the heliocentric theory “inconsistent with observations”¹. Although we would now say that the fact that they didn’t observe any such shift is consistent with the huge distances to the stars (and therefore small shifts) involved, for the ancient Greeks it was a problem. As Archimedes commented, if Aristarchus’ theory had been true, it would mean that the universe was much bigger than they at that time thought.

Guardini has written about the effect on the human psyche of this changing idea of the universe and our own place in it (from the Greek’s idea of finite and limited, to finite with a God outside, to infinite and back towards finite but incredibly large). Do our ideas, our models, about the universe affect not only how we interpret the experimental evidence we see, but also our way of being, our behaviour towards our fellow humans and our planet?

Viewing things from a different angle, seeing the effect of a change of line of sight, it brings us right back to the photography in the gallery and the twin lens camera on the shelf. There are certainly many things to contemplate while enjoying a coffee at The Observatory. Which means a second espresso should definitely be a possibility.

You can view some street photography, including some photographed with a twin lens Microcord TLR camera on Artemisworks gallery here.

The Observatory is at 64 Marchmont St, WC1N 1AB

¹Astronomy, the evolving universe (6th edition), Michael Zeilik, John Wiley & Sons, 1991

 

Categories
Coffee review Coffee Roasters General Observations slow Sustainability/environmental

Seeing the light at Redemption Roasters

Coffee Bloomsbury
Redemption Roasters Cafe on Lamb’s Conduit St.

At the top end of Lamb’s Conduit Street there is an unassuming café in a fairly modern building at the corner of Long Yard. In recent weeks I had been hearing a lot about Redemption Roasters and their café. First came the review by Double Skinny Macchiato, then various comments on Twitter, in Caffeine magazine and finally, an article in the FT. In an ideal world, it seems to me that cafés can act as seeds towards forming a better society. Local and independent, a friendly place where you can chat with the baristas (or café owners), and so where communities can form and develop. All that I had heard about Redemption Roasters café fitted, in some way, into this ideal which meant that it was not going to be long before I headed towards Bloomsbury and tried this new café.

Plenty of seating could be found inside the café, with tables of two or four and benches around the space. The counter was immediately in front of us as we went through the door and the friendly barista took our order (long black and soya hot chocolate, what else?) while we took our seats. There were a fair few staff in the café when we visited, so many in fact that we weren’t initially sure who were staff and who were customers. Nonetheless, their joviality transformed the café’s fairly austere decor more into the feel of the welcoming space of a living room.

blue shadow, hot chocolate
A layered hot chocolate? No, just the reflection of the saucer in the glass.

Having taken our seats and started to look around, we found that much could be said about the science in this café. From the SMEG refrigerator and individual radiators to the light reflection off individual sugar crystals in a glass on the table. Moreover, when our drinks arrived, the reflection of the (blue) saucer in the hot chocolate glass made it appear as if the hot chocolate were layered. In fact it was an optical illusion caused by the way our minds process the colour blue in shadows, more on that in this great article about colour, Goethe and Turner. But it was to a different lighting effect that my thought train eventually turned. Above the counter are a series of hanging lights with angular shades over them. Above our table were LED bulbs inset into the ceiling.

The way that the LEDs above us had been placed produced two shadows from the spoon on the saucer of my cup. A dark shadow and a light shadow at a slightly different angle. One reason that LEDs have caught on as a light source is that they are more efficient and so better environmentally and cheaper financially. So you may think that LEDs are one way of reducing our (collective) environmental footprint. But does this work? According to a study that measured the outdoor light levels around the world from 2012 to 2016, the answer is no. It would appear that while on a local level, people are enjoying cheaper lighting, on larger scales (nationally, globally), this decreased cost is leading to us installing more lights. Consequently, on the global scale, the area of land that is lit has increased by 2.2% per year with very few countries showing a reduction or even a stabilisation of the amount of outdoor areas that are lit.

shadows from a coffee Redemption Roasters
Determining a presence by noticing an absence. The two shadows of the spoon came from the light bulbs inset into the ceiling.

Does this matter? Well, it is something that is affecting us, the way we view our world and the wildlife that we share our planet with and so it is something that we ought to be thinking about. In brightly lit areas of the UK, trees have been shown to produce buds up to 7.5 days earlier than in darker areas. Artificial light is causing problems for nocturnal insects and animals, with knock on effects for crop pollination. And when was the last time you looked up at the sky on a clear night and saw seven of the Pleiades let alone the Milky Way? How does it change our psychology and philosophical outlook when we can no longer gaze at the night sky with wonder and without the glow of streetlights?

Some astronomers have called for increased shielding of street lighting as a way for us to both enjoy well lit streets and be able to enjoy looking up at the night sky. Shielding such as that over the lights over the counter at Redemption Roasters café, where the light is efficiently directed downwards rather than be allowed to escape into the sky. Small steps that can make a big difference. It is interesting to notice that around central London at least, many newer lampposts are more efficiently shielded than older ones. Pausing for a coffee in Redemption Roasters café is a great moment to consider this problem and your reaction to it. Have you stopped to gaze at the night sky recently?

After leaving the café, I realised I had lost an opportunity to notice something else. Frequently, after visiting a good café, I will look up the area in my London Encyclopaedia¹ to see whether there is anything of interest historically in the area of the café. As expected, Lamb’s Conduit St was named after a conduit made from a tributary of the river Fleet restored by one William Lamb in 1577. But Lamb also donated 120 buckets for poor women of the area to use for collecting their water, which explains the statue of a woman with an urn at the top of the street. However what was also mentioned was that at the entrance to Long Yard (ie. very close to Redemption Roasters) there is an ancient stone inset into a wall with a description about the Lamb’s Conduit. Somehow I missed this though Double Skinny Macchiato evidently found it. So if you do visit Redemption Roasters café, and I would very much recommend that you do, as well as taking some time to savour the coffee and to notice the surroundings, please do look out for this elusive stone and if you find it, do let me know.

¹The London Encyclopaedia, Weinreb, Hibbert, Keay and Keay, MacMillan, 2008

Redemption Roasters Cafe is at 84 Lamb’s Conduit St, WC1N 3LR