Category: Coffee review

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Coffee review General Observations slow

2 years in

3D hot chocolate art on an iced chocolate, Mace, Mace KL, dogs in a chocolate
Happy birthday to me

Last weekend, Bean Thinking turned 2. So I’ve been looking back at the cafés I’ve visited over the past two years. Bean Thinking started as a way to slow down and to try to see things in a (slightly) different way, to really enjoy the coffee but also to take time to explore the stories, and the science, that can be found in different cafés. I’ve enjoyed the coffee in each café that I have visited but, as always happens, some stick in the memory a little more than others.

So I decided to pull together five cafés which, for me, had an interesting story to tell or prompted an unexpected chain of thoughts. I have sadly had to leave out some great cafés and some really fun stories (for me to think about at least). However, these five stood out. Each café introduced an unexpected bit of science to me, or had something about them that meant that slowing down and enjoying the coffee provided a really special moment. Consequently, each café features for slightly different reasons, and so rather than create a top 5 (which would be impossible anyway), I have listed them alphabetically. I hope you’ll excuse this trip down memory lane.

Amoret, Hammersmith

Kettle drum at Amoret
Coffee on a drum at Amoret

It is not every day that a well made V60 can transport you to another planet. Yet that is what happened for me at Amoret in Hammersmith. The cylindrical design of the table reminded me of a drum but the question is, why do drums make the sounds that they do? The answer to this question took me on a journey into sounds. Just how different would Bach’s famous fugue sound if played on Venus rather than Earth? And then a surreal moment as a Dutch TV station decided to take Bananarama to Venus courtesy of research conducted at Southampton University. This was all accompanied by great coffee in a very pleasant cafe, the review can be found here.

Coffee Affair, Queenstown Road,

Contemplating the floor at Coffee Affair
Contemplating the floor at Coffee Affair

Where better to slow down and appreciate the moment than a place reminiscent of the geology of the South Downs that helped Charles Darwin to argue the case for his theory of evolution. Coffee Affair occupies the old ticket office at Queenstown Road station. The fixings and the floor of the café reveal evidence of the people who inhabited this space in times past. Watching the V60 being prepared, slowly, carefully, exactly, emphasises this sense of time. The result is great coffee in a place that almost forces you to step out of the speed of modern life and stop, put down the smart phone and take time to just notice. Coffee Affair was reviewed here.

Lumberjack, Camberwell,

Lumberjack coffee Camberwell
Exploring local connections at Lumberjack

There’s a strong emphasis on keeping it local at Lumberjack in Camberwell, as well as a preoccupation with all things wooden (this being an enterprise set up with London Reclaimed). So it was interesting to discover that there was a fairly local connection between Camberwell and the ultimate ‘local’ London tree, the London Plane. Not only that, but research that had been published a few weeks before I went to review Lumberjack had shown that, surprisingly, the wind speed needed to fell a tree was fairly constant at around 56 m/s, irrespective of the size or type of tree. This surprising finding was the cherry on the cake for this ultimate in local reviews (here).

Red Door, Greenwich,

vortices, turbulence, coffee cup physics, coffee cup science
Beautiful physics at Red Door

Just what would happen if you put a cup of coffee on a record player? A turntable in a corner at Red Door in Greenwich meant that not only did I start to think about this question, I decided to start some experiments to find out. The resulting physics was physically as well as scientifically beautiful. The experiments can be done by anybody with equipment that you can probably find at home (though I would recommend not using an actual turntable). It turned out to be an elegant experiment involving vortices, but as Helmholtz noticed, similar vortices form in organ pipes, the atmosphere and even in electromagnetism. Truly a beautiful piece of connected physics that I would have missed had I enjoyed my coffee ‘takeaway’. More here.

The Turkish Deli, Borough Market,

Turkish coffee
The universe in a cup of coffee at The Turkish Deli

“The universe is in a glass of wine” so said a Greek poet according to Richard Feynman, but at the Turkish Deli it is more obvious in a cup of coffee. When made properly, Turkish coffee requires at least four minutes of ‘settling time’ before it can be enjoyed. You could use this time to think about how the concentration of coffee particles changes as a function of the depth. Similar considerations led Jean Perrin to conduct experiments back in 1910 that he declared showed that “… it becomes very difficult to deny the objective reality of molecules” (which before that point had indeed been very much denied). Now that The Turkish Deli also roast and grind their own coffee on-site, there is even more reason to visit and ponder the connectedness of our coffee and our planet. The Turkish Deli was reviewed here.

With so many more cafés to explore, and things to discover, who knows what the next year or two will bring. And if you’ve got a recommendation or found a great café where you have stopped and noticed something intriguing, no matter how lateral, why not drop me an e-mail, I’d love to hear your experiences of slowing down and appreciating our coffees.

 

Categories
Coffee cup science Coffee review General Observations Sustainability/environmental Tea

A cup of tea for a light bulb moment at Ginger and White, Hampstead

Coffee, Ginger and White, Hampstead
Coffee at Ginger and White, Hampstead

It was late afternoon by the time we stopped by Ginger and White in Hampstead. The warm weather meant that we could enjoy time spent sitting outdoors in the little alleyway in front of the café. We had been taking a friend around the various sights (and foodie places) of London and so stopped here before heading back home. The long black, cortado and soya latte were all very well done and, while the others had enjoyed a crepe at La Creperie de Hampstead just around the corner, I took the opportunity to try the excellent banana bread on offer at Ginger and White. There was a fairly good selection of cakes on offer, but sadly those that the staff could confidently affirm were nut free were far fewer. However, the moist and tasty banana bread was a good option anyway. Coffee was roasted by Square Mile and there were also Square Mile beans available for purchase should you wish to take some home with you. While the café was fairly busy, it was nevertheless a relaxing place to sit and watch the people of Hampstead go by.

The interior of Ginger and Whites
Everything is connected. From the lights to your cup of tea.

As I was looking around, wondering what the physics part of this cafe-physics review would be, I had what you could call a “light-bulb moment”. The walls of the building opposite were reflected in the windows of the café but looking inside, I noticed the lights which appeared to be LED lightbulbs set-back into the ceiling. Along with requiring less energy to power than conventional or halogen lightbulbs, LED lightbulbs in a café offer another, more poetic advantage for the café: they have a connection to the drinks being served and particularly tea. It’s all about diffusion.

At the heart of an LED light, there are two materials that form a junction. On one side of the junction is a semiconductor material that conducts electricity by means of electrons. Electrons conduct electricity in metals and are the ‘normal’ way that we consider electrical current to  be carried. On the other side of the junction is a different semiconductor, one that still conducts electricity but this time does so with carriers called ‘holes’. You can view the electrons as having a negative charge and the holes as having a positive charge.

tea bag, tea cup, diffusion, turbulence
What happens when you put a tea bag into a cup of cold water. How long until the water becomes ‘tea’?

But what happens at the junction? Is there really a sharp barrier between these two types of material? Think about putting a tea bag in a cup of cold water, does the tea bag just sit there or does it slowly, very slowly, start to diffuse tea into the cold water? It is a similar thing for the two materials. Slowly the electrons diffuse into the hole material and the holes into the electron material. In fact, mathematically, the same equations describe the process in the junction as in the tea cup. But unlike tea, in the LED, the holes and electrons have an electric charge associated with them and so, as they diffuse away from the junction, they set up an electric field across the junction. It is this electric field that eventually stops any further diffusion of electrons or holes across the junction and sets up the conditions necessary for LEDs to emit light. It would be like having a tea bag that diffuses tea into the cup until it is perfectly brewed and no further.

Of course, there is much more than this to understanding LEDs. If you’re interested, there is further information here. I find it fascinating however that what happens in your tea cup, is also happening on many different scales in many places in the universe. And of course, in the lighting of cafés and coffee houses around the world.

Ginger and Whites is at 4a-5a Perrins Court, NW3 1QS

 

Categories
Coffee review General Observations slow Sustainability/environmental Tea

Environmentalism inside and out at Farmstand, Covent Garden

Farmstand Drury Lane
Farmstand on Drury Lane

How can we live sustainably, buying locally, being mindful of our ecological footprint and still drink coffee? A recent trip to Farmstand on Drury Lane revealed a café conscious of its environmental responsibilities, somewhere that is trying to help us to make a difference while still enjoying good food and great coffee. Is it possible for us to have our coffee and drink it? The people behind Farmstand certainly seem to think so.

The bare brick walls inside the spacious Farmstand have a certain rustic charm that serves to emphasise the environmental concerns of the café. A focus on local, free range meat and GM free vegetables means that this is definitely a place to be considered when looking for a lunch spot (though on this occasion, we only tried the coffee). Coffee is obviously not locally grown but is roasted by Workshop which is, relatively speaking, just down the road. Tea meanwhile comes from Postcard teas, just up the street. Water is complementary and is provided on tap so as to reduce plastic waste. The service was friendly and with such a bright and airy feel it is a very pleasant space to enjoy an Americano (though I imagine it is fairly crowded at lunchtimes). However, the Americano was served in a take-away cup (when I specified I was staying in). After a bit of digging on their website, I discovered that they use compostable and/or recyclable packaging sourced from London Bio Packaging. However, as it is not easy to either recycle nor to compost cups in regular waste collection (including recycling collections), it would be interesting to know details of how they dispose of their cups so as to know how they reconcile this with the otherwise careful environmental policy.

Interior vertical gardening
Green wall inside Farmstand

As you enter the café, there is a staircase on the left hand side. Potted plants are fixed to the railings making what seems to be almost a miniature green wall. A great way to get houseplants into a small space, this seemed a small scale example of the green walls that are starting to pop up around our cities. Green walls are vertical gardens. They can be grown either with climbing plants or with a second structure on the wall that supports the hundreds of plants. Along with an aesthetic appeal (certainly true of the structure at Farmstand), these green walls have environmental benefits too.

A big environmental problem in cities is particulate pollution from exhausts. Specifically, particulate matter that is less than 10 μm diameter (think Turkish coffee grind) can irritate the lungs and cause health problems for the city’s inhabitants. Particulates less than 2.5 μm diameter are even more dangerous to health. Worldwide, in 2012, 3.7 million early deaths were associated with poor air quality. In London, a 2010 study showed that approximately 4000 deaths per year were the result of exhaust fumes. Which brings us to the first reason that green walls in cities may be such a good thing: Plants adsorb the pollutants.

Green wall Singapore
A green wall at the Ocean Financial Centre in Singapore, Image shared under cc license (attrib. share alike) by smuconlaw.

Over a three month period, a study by Imperial College showed that a single green wall on Edgware Road tube station had removed 515 g of particulate matter from the atmosphere. Using a mix of plants on the wall was found to increase the air turbulence around the wall and so increase the adsorption of the pollutants. Of course, different plants performed differently (in terms of their ability to remove particulate matter from the air). One of the plants on the wall (Convolvulus cneorum) could take out up to 2.73±0.16 g/m² of particulate matter*. On the other hand, another plant on the wall (Hedera helix) took out much less, removing only 0.28±0.02 g/m². However, we know Hedera helix by another name: Ivy. And ivy plants can produce a lot of foliage per plant very quickly. Convolvulus cneorum on the other hand, is a small plant with small leaves. While its efficiency could be very high, the amount of pollution it can remove may not be as great as an ivy plant, purely as a consequence of its leaf size.

Which brings us to questions of aesthetics and practicality. The wall at Edgware Road is planted with many different types of plant in order to produce an effect that reduces pollution while also being good to look at. Similar walls have sprouted up all over the world. However, for short term projects that require a large amount of foliage quickly, planting ivy can be a good option as a pollutant remover. Some of the temporary structures built along Park Lane for the Crossrail project are now covered with ivy. Although I had initially thought that this was due to a lack of weeding, it turns out that this is part of a step towards pollution reduction in our cities (modelling data has indicated that these green walls can reduce the local particulate pollution by 10-20% depending on the geometry of the wall and the plant species growing).

A small step perhaps, but one that is definitely in the right direction. The green wall at Farmstand could therefore be said to illustrate the idea that if we are to make a difference to our external world, we must start by reforming our own interior one. We need to make green walls not green wash and we can start by paying attention to what we plant inside and out.

Farmstand is at 42 Drury Lane, WC2B 5AJ

*The study looked at particulate matter between 2.5 µm and 10µm diameter (i.e. PM(2.5)-PM(10)).

 

 

Categories
Coffee review General Observations

A sense of history at Lundenwic, Aldwych

Lundenwic Aldwych coffee
The bar at Lundenwic

Of all the senses, our sense of smell is probably the one that is most likely to evoke memories that can take us right back to our childhood. One whiff of something as we walk past a café can, almost magically, transport us back many years and to a quite different time and place. This aspect of our sense of smell was brought home to me a few weeks ago on a visit to Lundenwic in Aldwych.

Lundenwic was the Anglo-Saxon name for the settlement that was located between what is now Covent Garden and Aldwych. As time progressed and the population of Lundenwic decreased, the site became known as the old-settlement (Aldwic), from which we get the name Aldwych*. Lundenwic is also the name of a (relatively) new cafe that has opened up near the corner of Aldwych with Drury Lane (incidentally, originally called the Via de Aldwych*). The upstairs seating area is quite small but with Caffeine magazines on hand, and plants dotted around, as well as the bar, there is plenty to watch and to notice while savouring your coffee. The espresso based coffee is sourced from Workshop while the filter option (V60 based) features different guest beans. On the day of our visit there were two filter options available. Opting for the Kenya Kagoumoini AA, I waited for my coffee to be prepared while my cafe-physics review companion had a late lunch of a cheese and ham toasty which quickly filled this small café with the aroma of cooking cheese. The tasting notes for the coffee stated that I should expect “rhubarb and raspberry lemonade”, and while the taste was certainly of lemonade, the aroma seemed to me quite different, almost spicy.

Lundenwic coffee
Kenyan coffee, freshly brewed appealed to all five senses, but each in different ways.

The cooking cheese and the memories evoked by the smells, along with this difference between the smell and the taste of the coffee, suggested that smell ought to be the subject of this cafe-physics review. Indeed, smell turns out to be a very interesting sense. The nerve cells relating to smell are the only type of nerve cell that can regenerate†. It is this ability of these nerve cells to regenerate that recently helped a previously paralysed man to walk again. Nerve cells from his nose were transplanted into his spinal cord where they helped in the regeneration of his spinal cord (for reasons that are not yet fully understood).

But what about those smells in the coffee? That special aroma, that you breathe in and appreciate immediately after you have brewed your cup is due to a fantastic mix of over 1000 volatile aroma chemicals. If you let your coffee stand, those chemicals evaporate off, which means that the just-brewed aroma starts to change. One of the most important chemicals for this coffee aroma is called 2-furfurylthiol. It has been shown that the concentration of 2-furfurylthiol in the coffee decreases by a factor of 4 over the course of an hour‡.  Even after as little as twenty minutes or so, the concentration of these complex aroma molecules starts to decrease significantly and so if you, (horror of horrors), were to let your coffee cool overnight and then zap it in the microwave in the morning, you would no longer regain that freshly-brewed smell that may have attracted you to the coffee in the first place.

durian skins and seeds
What was left after a session eating durian on a durian farm in Penang, Malaysia

This may also be the reason that the coffee at Lundenwic tasted differently to how it smelled. By inhaling the aroma and then tasting the coffee without exhaling (and so pushing the aroma back through the nose), our nerves are sensitive to different sensations. Although we may experience this while tasting many foods, occasionally it is crucial. A few years ago, Hasbean coffee were selling a very unusual coffee. The coffee, from Indonesia was called “Sidikalang”. Looking back at Hasbean’s “Inmymug” video, it is clear that it was very difficult for Hasbean’s Stephen Leighton to come up with tasting notes for the coffee which, in the end was compared with “durian”. The aroma of durian has been described as “turpentine and onions garnished with a gym sock” and yet in South East Asia it is known as the King of Fruits and is highly sought after for its taste. The aroma chemicals found in durian have recently been analysed (by the same group as studied the aroma of coffee). Nonetheless, the inclusion of “durian” in the tasting notes was extremely accurate (and did result in an amusing, if unconventional, attempt at opening one of the fruits in the video). It was accurate not only in terms of the experience of the taste/smell combination of that coffee. The actual taste and smell of the coffee was very similar to that of durian. A very unusual and interesting coffee that I have never yet had the opportunity to experience again.

However, to return to Lundenwic, how do the (lovely and inviting) smells that emanate from that café compare with the smells of the area that had been Aldwych before 1905 (when Aldwych was built, demolishing the slums that had existed there)? Some museums, such as the Canterbury Tales (in Canterbury), use the aromas (odours?) of medieval life to give visitors some idea as to what life was like in years gone by. Recalling a childhood visit to that museum, I would suggest that the smell of freshly brewed coffee and melting cheese is an almost unquantifiable improvement.

Truly we could say that at Lundenwic, it is time to wake up and smell the coffee.

Lundenwic is at 45 Aldwych, WC2B 4DR

*The London Encyclopaedia, 3rd Ed, MacMillan publishers, 2008.

†”On Food and Cooking: The science and lore of the kitchen”, Harold McGee, George Allen & Unwin publishers, 1988.

‡The coffee had been held at 80C in a thermos flask for the duration of the experiment. It may be expected that as your coffee cooled down, the volatile aroma molecules would evaporate more slowly than the time indicated in this study.

 

 

 

Categories
Coffee review Home experiments Observations

Reality bites at Chin Chin Labs, Camden

Coffee grinder at Chin Chin Labs Camden
Nitro-brew? Not this week. Coffee and liquid nitrogen at Chin Chin Labs (a nitrogen dewar is on the table behind the coffee grinder).

It is true that Chin Chin Labs is not really a coffee-based café (although it does serve decently prepared, Monmouth roasted, coffee). Nonetheless, there is no question but that it has to be included as a cafe-physics review on Bean Thinking. Why? The answer is in the photo of the coffee grinder, though you may have to look carefully. You see, Chin Chin Labs is offering a different sort of café experience. Not coffee nor tea, but ice cream, indeed, Chin Chin Labs in Camden Lock advertises itself as the ‘future of ice-cream’ and the reason it does so is because here, all the ice cream is made with liquid nitrogen.

There are only 3-4 tables inside Chin Chin Labs which makes it more of a take-away bar than a sit down café. As you enter, a large dewar of liquid nitrogen is on your left, just behind the counter. Arranged behind this large dewar are a set of smaller dewars while on one of the ice cream preparation tables another (small) dewar sits with a pipe in it, ready for the nitrogen to be decanted out. If all these dewars are full, that is a lot of liquid nitrogen. The coffee is decent and prepared in the normal styles (espresso, Americano, cappuccino, latte), though this place is really not about the coffee (one of the staff expressed surprise that I’d ordered a coffee and not an ice cream). Next to the espresso machine were a set of glass beakers and glass containers as you would expect to find in a chemistry set, while the aprons worn by the staff had “Chin Chin Labs” written in a glittery, (futuristic or disco?), font.

Various dewars of nitrogen
Nitrogen, nitrogen everywhere…

There are many fun things that can be done with liquid nitrogen. From creating ice cream, through to shattering flowers and even to a possible solution for the energy storage problem (info here). Not to mention its important use as a coolant in all sorts of physics experiments and for biological storage. I have spent many hours decanting liquid nitrogen into buckets for basic experiments or into the first cooling stage of very strong magnets (such as are used in MRI machines).

However, at -196ºC, liquid nitrogen is not a liquid that can be treated flippantly. Although it can be fun, and handled correctly there is no problem, it can nonetheless be very dangerous. Which is why something else about Chin Chin Labs struck me quite hard. While there were glass beakers and containers that a cartoon may feature as part of a science ‘lab’, there was none of the equipment that you would actually expect to see in a real lab where liquid nitrogen is used. In our lab, oxygen monitors beep (annoyingly) every 60 seconds*, eye goggles and proper cryogenic-suitable gloves are stored in a highly visible position easily accessible to anyone in the lab. Risk assessments are prominently displayed so that everybody is aware of the risk of oxygen depletion (leading to suffocation) were the nitrogen dewars in the lab to fail and suddenly vent all that liquid nitrogen into nitrogen gas in the lab. These things are not fun, but are a necessary part of running a lab in which cryogenic liquids (including liquid nitrogen) are stored and used.

Ice cream at Chin Chin
The final result: vanilla nitrogen-ice-cream.

It is this contrast, between what is expected of a lab (glass beakers and complicated looking valves on the dewars) and what is in a lab (safety equipment and complicated looking valves on the dewars) that struck me. What do people, the public, café owners, think a lab looks like? What do they (you?) think a scientist looks like? Do we prefer indulging in our stereotyped ideas of a lab rather than think about the reality of life in a real science lab?

I am sure (or at least I hope) that the safety equipment, oxygen monitors etc. are present, but hidden under the counter, at Chin Chin Labs. It should always be possible to have fun with liquid nitrogen, whether in a lab or a café. And the ice cream is definitely worth trying (according to the person I visited Chin Chin Labs with). But, if you happen to pass by Camden Lock and try some nitrogen ice-cream, please do spend a minute to ask yourself, what you think a scientist, or a lab looks like. And do let me know what you think, I’d be interested to know.

Chin Chin Labs is at 49-50 Camden Lock Place, NW1 8AF

* In the event of the failure of a liquid nitrogen dewar, the oxygen in the room would be displaced. The resulting decrease in oxygen concentration can cause sleepiness, mental confusion or in the case of severe oxygen depletion, coma and death (more info here, opens as pdf). Oxygen monitors check the oxygen level in the room is at a safe level. The beep is annoying but tells us that the monitor still has battery and is checking the oxygen level in the room.

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

Counting the caloric at Jaz & Jul’s Chocolate House, Chapel Market

Jaz Jules chocolate house
Jaz and Jul’s, The Chocolate House on Chapel Market

The London coffee houses of the seventeenth and eighteenth centuries have entered history as Penny Universities, places of debate and centres of news. Together with the (scientifically based) Grecian, there was Jonathan’s in Exchange Alley (origin of the stock exchange) and Lloyd’s on Tower Street (associated with insurance). But along side these coffee houses there were the chocolate houses, Whites and Ozinda’s on St James’ St and the Cocoa Tree in Pall Mall. White’s in particular developed such a reputation that it features in Hogarth’s The Rake’s Progress (which can be seen at Sir John Soane’s museum).

So it is an interesting bit of history repeating to find Jaz & Jul’s, a chocolate house on Chapel Market. The interior here is very far from Hogarth’s rendering of White’s. Here, light fittings hang from the ceiling like drops of chocolate about to melt into the café while photographs of cocoa plants and farms adorn the walls. Moreover the emphasis on social responsibility, including in sourcing, mean that this establishment is worlds away from the debauched shenanigans at White’s. Their coffee is roasted and supplied by Monmouth while the cakes are hand made and, needless to say, very chocolatey. The light and fluffy chocolate-Pimms cake arrived with my coffee presented on a plate and matching cup that reminded me of a mint-chocolate-chip ice cream.

Interior of Jaz and Jules Chapel Market
The chocolate counter at Jaz and Jul’s

The side of the counter was tiled to resemble a bar of chocolate, which immediately reminded me of the physics and chemistry of chocolate crystallisation. However, the physics connection of this cafe-physics review is a bit more lateral than that. Soon after I had enjoyed my incredibly chocolatey cake at Jaz & Jul’s, a study was released which showed that Britons were significantly under-reporting their daily calorie intake. Could it be that the obesity epidemic is a result of us eating too much rather than merely exercising too little? Apparently, rather than consume the (recommended) levels of 2500 kcal for men and 2000 kcal for women, many people were eating up to 3000 calories per day. Everything in moderation of course and there was plenty of room in my own calorie count for that great piece of cake (honestly). But the word ‘calorie’ turns out to have a connection with chocolate in a more unexpected way.

Calorie comes from the Latin, calor, meaning heat which in turn hints at how we used to think about heat itself. While we now think of heat as energy, which is why it doesn’t even strike us to equate the ‘energy’ in the chocolate cake with the number of kilo-calories in it, this is not how heat was always viewed. In fact, in the eighteenth century, about the time of the old chocolate houses, heat was thought of as a type of fluid, caloric. Caloric was thought to be able to flow in and out of all substances. When something got hot it was because the caloric flowed into it, when something got cold, it was because the caloric had leaked out. Caloric theory was in many ways very successful in understanding heat and heat processes. For example, the theory easily explained thermal expansion, if a fluid had to flow into something in order for that thing to warm up, then surely, the fluid has to occupy some space, the object must expand to hold it!

Mint choc chip cutlery
Coffee with the Chocolate-Pimms cake.

One area that was tricky for caloric theory though was the fact that friction could cause something to heat up. Such heat generation is crucial for our extraction of chocolate. Once harvested from the plant and cleaned, the cocoa bean is first roasted then shelled to leave the cocoa ‘nibs’. These nibs are then ground more finely. As they are being ground, the friction caused by grinding is enough to cause sufficient heat to melt the cocoa butter in the nibs which is then extracted and retained for later use*. How could you explain this heating if you thought of heat as a fluid? The traditional explanation was that as the two objects rubbed against each other (in this case, nib and stone grinder), the caloric fluid would be squeezed out, it would appear as if heat had been generated.

Benjamin Thompson, Count Rumford (1753-1814), disagreed with this explanation of heat. In the course of a colourful career he had been involved in manufacturing cannons in Bavaria. Rumford had noticed that a lot of heat was generated each time a cannon shaft was bored out. The heat produced continued as long as the grinding continued. If the heat were due to the cannon leaking caloric, surely there would be a point at which the cannon stopped getting any hotter. Yet this did not happen. Rumford suggested (correctly) that instead what was happening was that the energy generated by the boring was being transferred into the metal of the cannon, causing microscopic motion.

Although the heat as motion/energy idea eventually caught on, caloric in some ways still survives in the name that we give to our food energy intake. And so we can return to the cake, could it be that spending time thinking about the caloric in the cake can justify the calories consumed eating it? Sadly the jury is out on whether thinking counts as calorie counting exercise. It seems that the brain’s energy consumption is already so great (at 20% of our resting metabolic rate), that intense thinking does not add too much to the energy consumed by the brain. So we’ll need another excuse and I don’t think we have to look far. The coffee and chocolate at Jaz & Jul’s is delicious enough to justify a significant chunk of your daily calorie count, just based on considerations of taste. Everything in moderation!

 

Jaz and Jul’s is at 1 Chapel Market, N1 9EZ

*”Chocolate: A Global History”, by Sarah Moss and Alexander Badenoch, published by Reaktion Books, 2009

 

Categories
Coffee review General Observations Science history slow Sustainability/environmental

Life at the Coffee Jar

CoffeeJar_exteriorI had been waiting for an opportunity to try the Coffee Jar for a fair while. It is not that it is in a remote location, it is in fact situated on Parkway just five minutes walk from Camden or Primrose Hill. Nonetheless it feels as if it needed a special trip to get there (and, though this is pre-empting the end of this cafe-physics review, it does deserve such a ‘special trip’). Inside, there is seating at the window and running along one wall, and although it is not the smallest of cafés, it is certainly a ‘cosy’ one. This is not intended as an estate agent’s euphemism but instead to emphasise the additional meanings of this word to convey a warmth and friendliness about the space that the Coffee Jar definitely has. So far, we have been twice (see, the ‘special trip’ is worth it!). The coffee comes from Monmouth and so unsurprisingly, on the two occasions I had a coffee there (Americano and Soya Latte), it was very well done and enjoyable. At the front of the counter are a wide selection of home made cakes and cookies. While this presentation can be awkward for allergy sufferers (nutty cakes or cakes with loose nuts on top are placed side by side with the nut free options which could give contamination issues), the cookies were very good (more on the cookies later).

As befits the name, hand painted jars and coffee mugs decorate the end of the tables (and can be purchased should you wish). Individual art pieces decorate the walls while the window is painted with a scene that is somehow mirrored (shadowed?) in the ink prints on the take-away cups. All in all, there is plenty to notice in this “cosy” space. And so it took a fairly long time before I noticed the fish that was dangling above my head.
robot fisherman, robot fisherwoman, coffee jar camden
Apologies for the blurry photo but you can see the robot fisherman on the shelf.

Yes, this seemed an odd thing to me too, so I checked and indeed, a wooden fish was suspended on a string from something hidden on the shelf above my seat. At this point, an opportunity arose to go and sit at the window and so I was able to turn and look properly at the cause of the suspended wooden fish which was actually a toy robot. It just gets more surreal. But indeed, on the shelf above the seats against the wall was a toy robot fishing, a wooden fish hanging at the end of his (her?) line.

A robot that is fishing can prompt a large number of questions which seem to me to be at the intersection of science and philosophy. To what extent has automation improved our lives? Is it a good or a bad thing to use robots in jobs traditionally done by humans? Moving away from robots and towards computers, what about artificial intelligence? Much has been written about artificial intelligence in recent years. There is some angst about whether robots will come to take-over the world with an ability to think that far surpasses our human ability. Alternatively, there are people who look to artificial intelligence with the hope that it will help us drive cars or investigate pollution or all manner of other (to a greater or lesser degree) useful things. One test that has been suggested as a way of establishing whether any particular computer, or artificial intelligence, can think is the Turing test proposed in 1950 by Alan Turing. A prize set up to reward the first computer “chatbot” that could reliably mislead human judges into thinking that it was itself a human (the Loebner prize) has so far not been won (a prize is awarded each year for the most convincing chatbot but so far, none has been so reliably convincing as a human to win the top, “gold” prize).
soya latte at the coffee jar camden
Unusually I had a soya latte.

But the robot on the shelf was not represented as thinking but as fishing, an occupation that is associated with relaxation. This robot was not just thinking, it was taking time out to relax; it was represented as being alive and sentient. This prompts a rather different question to that of merely intelligence: At what point do we say that something is living? How can we define life? As could perhaps be expected, NASA has taken some time to consider this question. As they say on their website:

“Comparing the semantic task [of defining life] to the ancient Hindu story of identifying an elephant by having each of six blind men touch only the tail, the trunk, or the leg, what answer a biologist might give can differ dramatically from the answer given by a theoretical physicist.”

Which may make you wonder well, what would a theoretical physicist say about how we could define life? Erwin Schrödinger (1887-1961) had a very interesting, physics-based, definition of life. Although he is now perhaps more famous for his equation or his cat, in 1944 he wrote a book called “What is Life” (opens as pdf). To very briefly summarise, the argument goes that the tendency of all inanimate objects is towards equilibrium. A hot cup of coffee will lose heat to its immediate environment and so reach the same temperature as its surroundings, a small amount of blue food colouring at the bottom of a glass of water will eventually colour the entire glass a paler blue. To be alive is to defer this state of equilibrium for to achieve equilibrium is the same thing as death. Schrödinger argued that rather than merely consume energy, living things consumed negative entropy from their food-stuff. Entropy is a quantity introduced with the theory of thermodynamics. It is often taken as a measure of the order in a system (though there are caveats to that). The second law of thermodynamics states that for a closed system, the entropy of the system will either increase or stay the same. This suggests that to avoid equilibrium, or equivalently to avoid death, the living thing must consume order (or negative entropy) and somehow stave off this tendency to maximum entropy. To answer the objection that it would be easy to consume negative entropy by eating diamonds (which are highly ordered crystals) and so therefore that there has to be more to life than this, Schrödinger expanded on the thermodynamics of his argument. That bit gets quite technical and so is another reason that, if you are interested, it is worth getting hold of the book.

 

So to return to one of the first questions but phrase it in a slightly different way. Could a robot cookie maker replace the “home-made” cookies that were on offer in the Coffee Jar? It turns out that this is a subject that my often-times cafe-physics review companion (let’s call them J) has quite an opinion about. We visited the Coffee Jar twice partly because of the cookies! It seems to me that J would not have been impressed by the cookies were they robotically mass manufactured. There was something very appealing in the home made quality of them. So, there we go, one of the questions answered neither scientifically nor philosophically but on the very reasonable basis that home made cookies taste and look better. Do let me know if you agree if and when you visit the Coffee Jar.
The Coffee Jar is at 83 Parkway, NW1 7PP
“What is life?” Erwin Schrödinger, Cambridge University Press, first published 1944, my edition published 2013
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cafe with good nut knowledge Coffee review Observations Science history slow

From Beethoven to Pythagoras via Kin Cafe, Fitzrovia

Kin Cafe Fitzrovia
Kin Cafe on Foley St

I had been waiting for an opportunity to try Kin Cafe in Fitzrovia for a while. Having followed them on Twitter, I had been tempted by the large selection of great-looking vegetarian and vegan food choices tweeted almost daily. Although I’m no longer a vegetarian, appetising meat-free meals are always appealing. So it had been on my “to try” list for a long time (preferably for lunch). However, sometimes things don’t work out quite the way you had initially hoped and so it was late afternoon by the time we ended up at Kin, sadly no lunch then. So we settled on an Americano, soya hot chocolate and a slice of Butternut and ginger cake. The coffee (from Clifton Coffee) was very fruity and full of character, highly enjoyable while sitting in the window overlooking the street outside. The cake meanwhile deserves a special mention. Not only was the cake very good, the helpful staff at Kin were very confident in their knowledge that this cake was nut-free and they also ensured that the new member of staff (being trained) used a new cake slice to serve it. Extra ‘points’ for a nut-allergy aware café and definitely a tick in the “cafes with good nut knowledge box”.

As we sat with our drinks, one of Beethoven’s quartets was playing through the loudspeakers. For me, Beethoven being played in the background is a bonus for any café but it did, perhaps, mean that I was less sociable than normal with my frequent companion in these reviews; the quartets are too absorbing. I do hope the hot chocolate made up for it.

Interior of Kin cafe
Tables are supported by struts forming triangles. But this is not the Pythagorean link.

Inside the café, tables along the wall were each stabilised by a diagonal support. A practical arrangement that had the visual effect of forming a triangle with the wall. While this did make me think about force-balancing and Pythagoras, this is not the link to Pythagoras alluded to in the title. No, instead the connection goes back to the Beethoven and the links between music and mathematics. Perhaps we no longer immediately think of music and mathematics as being particularly connected, after all one is an ‘art’ and the other a ‘science’. But music and mathematics have, traditionally, been so inextricably linked that, as Susan Wollenberg wrote in ‘Music and Mathematics’* “… it is their separation that elicits surprise”.

Some of the links between music and mathematics are explored in this TED-Ed talk about the maths to be found in Beethoven’s Moonlight Sonata. This part of the link between music and mathematics comes in the relation between what is known as consonant and dissonant notes. The first part of the Moonlight Sonata is made up of triplets of notes that sound good to our ears when they are played together. As Pythagoras is said to have discovered (see link here, opens as pdf), there is an interestingly simple relation between notes that are consonant with each other. Whether you look at the frequency of the notes or the length of a string required to play them, the ratio of two consonant notes seems to be a simple number ratio.

For example, the A of an oboe has a frequency of 440 Hz*. The A one octave higher is at 880 Hz, a factor of 2. If we took instead a series of notes of frequency f, then we could find a series of consonant notes at f:2f:3f. But now, remembering that octaves are separated by a factor of 2 and that they ‘sound good’ together, this will mean that the ratio of frequencies f:1.5f:2f will also sound good. This set of frequencies just happens to coincide with the C-G-C’ chord that forms the basis of many guitar based pieces of music. As you continue looking at these simple number ratios you can start to build a set of notes that eventually forms a scale.

Blue plaque Foley St
The artist Fuseli once lived diagonally opposite Kin Cafe. J. James notes that Fuseli was part of the artistic revolution that was paralleled by Beethoven and the Romantics in the musical sphere**.

But the links go deeper than this. In the same book “Music and Mathematics”, JV Field wrote “..in Ancient, medieval and Renaissance times, to claim that the order of the universe was ‘musical’ was to claim that it was expressible in terms of mathematics.” Indeed, Kepler looked for these musical harmonies in the maths of the planetary system. Although he found no ‘harmonies’ in the ratio of the periods of the planets then known, he did find musical scales in the ratios of the speeds of the planets (measured when they were closest to the Sun, at the perihelion, and furthest from the Sun, at the aphelion). Other simple number ratios can be found when we look to different regions of the Solar System. The periods of three of the Galilean moons of Jupiter for example have the ratio 1:2:4 (Io:Europa:Ganymede). While we would no longer describe these patterns as reflecting the harmony of the Universe (see here instead for current understanding), perhaps we ought to ponder the next sentence that Field wrote in the chapter on Musical Cosmology:

“We still believe [that the universe is expressible in terms of mathematics] now. Indeed, mathematical cosmology has proved so powerful that it is perhaps difficult to take a sufficiently cold hard look at the metaphysical basis on which it rests. On the other hand, the explicitly musical cosmologies derived more directly from the Ancient tradition seem sufficiently fantastic to invite instant questioning of their underlying metaphysics…”

One to consider next time you happen to wander into Kin Cafe, or another café playing such mathematical composers as Beethoven.

Kin Cafe can be found at 22 Foley St, W1W 6DT

*Music and Mathematics, Edited by J. Fauvel, R. Flood, R. Wilson, Oxford University Press (2003)

** The Music of the Spheres, J. James, Copernicus (Springer-Verlag), (1993)

Lastly, a video of Wilhelm Kempff playing Beethoven’s Moonlight Sonata. I would really recommend playing it twice, the first time to listen only, the second to watch while Kempff plays. His performance is fascinating.

 

Categories
Coffee review Observations

Grass or clay at Brickwood, Clapham

coffee Clapham common
Weather for Wimbledon? It was raining when we tried Brickwood in Clapham

It was raining heavily as we met friends for coffee at Brickwood, near Clapham Common, a few weeks back. Inside it was fairly crowded so we were shown to a cosy little area downstairs where we found a table. The staff were all friendly and with coffee roasted by Caravan, it was easy to sit and enjoy a great Americano while waiting for the others to arrive. Sadly, all of the cakes on the menu contained nuts (with the exception of scones). This was a shame because it was otherwise an interesting place to sit and observe the surroundings and it would have been nice to have been able to give it a ‘tick’ in the cafes with good nut knowledge box*. Still, the coffee was very good and there was plenty to observe, even in the basement.

Glancing around the room, the first thing that struck me was a white board on the wall. Taken together with the artificial lighting (necessitated by the area being in the basement), this was highly reminiscent of the maths ‘common room’ at work. A further mathematical connection comes from the fact that the grandfather of John Venn (of the Venn diagram) lived nearby. A prominent local clergyman, Venn St, just around the corner from Brickwood, is named after him. Still, that is quite a digression. There were also interesting bits of physics and science to notice in the café itself.

the 'carpet' of the floor at Brickwood
Grass or concrete? What factors control the bounce of a tennis ball.

Downstairs, the floor was covered in what appeared to be an artificial grass. This gave the whole experience of having a coffee here a bit of a surreal twist. Just as happens with real grass, a path was visible on the ‘grass’ where people had walked, something that can be used when rambling in the country to help you find your way around (when GPS or map temporarily fail you). The book “The Walker’s Guide to Outdoor Clues and Signs” gives many such details about how to navigate in the country without a map (including how to tell from trees which way is North).

However, as we are now in the second week of the Wimbledon Tennis tournament, this cafe-physics review is going to have a tennis slant instead. We could think about how different it would be were we to drop a tennis ball onto the ‘grass’ downstairs, or (what I remember to be) the wooden floor upstairs. Tennis started off as an indoor sport, played on courtyards in stately homes and monasteries. ‘Lawn tennis’, or what we now recognise as just ‘tennis’, developed in the nineteenth century and was played on grass. Thinking about how a tennis ball would  bounce on the floor in the basement or upstairs in Brickwood is therefore somehow reminiscent of the history of the sport.

whiteboard, Brickwood, Clapham
Like being in the maths common room but with better coffee and flowers

Tennis balls are designed to bounce 53-58 ” (134.6-147.3 cm) when dropped onto a concrete floor from a height of 100″ (254 cm). Other surfaces have different elasticity and/or friction. The behaviour of the ball will be quite different therefore when it bounces on different surfaces, affecting the speed (and therefore height) and even angle of the bounce (for more info on the physics click here). The different characteristics of the surfaces mean that different types of play are required to succeed on the court. To be successful across all courts (from the clay of Roland Garros to the Decoturf of the US Open and the grass of Wimbledon) requires a tennis player who can adopt many different playing styles. Would it help a tennis player to have a training in physics and an understanding of the details of aerodynamics, spin and friction that are involved as the ball whizzes through the air? Probably not. But for us mere observers who prefer eating the strawberries and cream and savouring great coffees while discussing the game, a bit of physics may perhaps add to our enjoyment.

Brickwood (Clapham) is at 16 Clapham Common South Side, SW4 7AB

*to be fair, Brickwood did have “good nut knowledge”, they knew all their cakes contained nuts. Perhaps the tag needs revising to be “nut-allergy-friendly”.

Categories
cafe with good nut knowledge Coffee review Observations Science history

It’s a kind of magic at Kaffeine

Kaffeine_neonIt’s nearly 7 years since Kaffeine first opened its doors on Great Titchfield St, but Kaffeine on Eastcastle Street is a new addition having opened just over a year ago. We visited the younger Kaffeine a couple of weekends ago when looking for a coffee in the Oxford St area. Along with an iced coffee, an Americano and a long black, we had a raspberry/cashew slice and a slice of banana bread. It was a relief to find that Kaffeine had a good nut policy so I could confidently enjoy my banana bread, knowing it was nut-free, while a friend devoured the cashew containing slice. The staff were attentive and friendly and there was plenty of space inside to sit and chat while taking in the surroundings. In this regard, it was nice to see this same point being made on Kaffeine’s  own website where it says that you can “…sit at the high stools at the massive sun filled front windows and watch the world go by”.  With the accompanying coffee, what more could you want? The coffee was, of course, very good (beans from Square Mile), and it was great to see that part of the philosophy behind Kaffeine is to take “the art and science and practice of making espresso coffee to a whole new level”. It’s always a pleasure to see those three distinct, but essential, elements combined. I do however remain unconvinced that many could tell the difference (in a blind taste test) between an Americano and a long black.

wood and slate with glass, Kaffeine
The table top at Kaffeine, Eastcastle St.

Complimentary mint-infused water was on offer at the back of the cafe and, although this made the Daily Grind last week, there was just too much to notice at Kaffeine to make this the subject of the cafe-physics review.  Indeed, from the perspective of anyone who wants to slow down and notice things in a café, Kaffeine is brilliant. This cafe-physics review could have been about so many different things. There were the weights holding the door open in a pulley system. The trademark neon sign. The compact-ness of the cashew/raspberry slice or the reflectivity of the copper on the side of the counter. I was in cafe-physics review heaven! So many different mental alleyways to run down and explore as the different bits of physics came into view. From pulleys to Archimedes, cakes to ceramics science, copper to atoms or to the odd puzzle about the colour of gold, all these will have to wait for another time. This time, what struck me was not what could be seen but what could be felt.

Far from going into a subjective piece about the ambience of the cafe, I mean this statement far more literally. The table, with the wooden grain, felt rough. In the middle of the table, a piece of slate had a surface that was more smooth and then, on the walls behind us, highly glazed tiles were very smooth indeed. What do we mean by rough or smooth, how rough is rough, how smooth is smooth and what has it to do with the “magic mirrors” of Japan?

reflective tiles but not really flat yet
Smooth tiled wall at Kaffeine

The wooden bit of the table for instance has a surface that undulates with a height of the order of about a millimetre. The slate is far smoother but the surface would still be rough, probably on a length scale tens to hundred microns or so (about the size of espresso to medium grind coffee). The tiles are a lot smoother than both the wood or the slate but they are still not so smooth that they could be considered flat on an atomic scale. To be flat on an atomic scale, the surface would have to have a height variation 100 000 times smaller than the smallest particles in an espresso grind*. While some crystals can, naturally, have ‘faces’ that are this smooth, the semiconductor industry needs to be able to achieve this level of flatness routinely to provide the electronics for your smart phones, computers and even perhaps the electronic scales that are used to help you make your coffee.

copper mirror Kaffeine Eastcastle St
The mirror-like copper clad counter.

In ordinary life however, perhaps we think that a smooth surface is like that of a mirror. So it is worth taking a look at an odd type of mirror for which very small variations on the surface cause a very strange effect: the “Magic mirrors” of the far East. Typically made of bronze, these mirrors have been manufactured for nearly 2000 years. On the back surface of the mirror is an artwork (perhaps signs of the zodiac or other religious symbols) which is in relief. The front of the mirror meanwhile is highly polished but slightly convex. Looking directly at the front surface of the mirror, there is no visible sign of the image on the back. Maybe you don’t find this surprising, the mirror is solid bronze after all and we can’t see through solid metal. However, if you were to take a step back, shine light on the front of the mirror and look at the reflection of the mirror projected onto the wall, the image at the back can clearly be seen, there in the reflection (you can see photos of this effect here).

Initially this phenomenon was dismissed as ‘trickery’ but subsequent, careful, study showed that small deviations from perfect curvature on the reflecting surface were enough to cause the effect. Although the mirrors were cast and then polished, nonetheless, stresses and strains from the pattern on the back  had propagated through the atomic structure that forms the metal and resulted in tiny, invisible to the eye, changes on the front surface of the mirror. Sometimes it does appear that looking at things in a different light can really change our impression of what something is.

Kaffeine can be found at 15 Eastcastle St. W1T 3AY

* Scaling to coffee grind size approximate but based on measurement of grind size reported here.