microscopic coffee – Bean Thinking

Last week, a new study was published that explored the mathematics behind brewing the perfect filter coffee. The research, summarised here, modelled the brewing process as being composed of a quick, surface extraction from the coffee grounds, coupled with a slower brew, where the water was able to get into the interior of the coffee grind. It was an interesting study and the authors are now looking at grind shape and the effect of how you wet the grounds. However, what struck me was that the authors mentioned scanning electron microscopy (SEM) images of ground coffee. A lovely idea, what does coffee look like when magnified hundreds (or thousands) of times?

So here are a few images that I found shared under Creative Commons Licenses. I hope you find them as fascinating as I do.

1) A green coffee bean:

Green coffee bean under the microscope — A green coffee bean. Sadly no details as to magnification. Image shared under CC license from Nestle, Flickr

2) Instant Coffee

Instant coffee from Nestle — Spray dried instant coffee from the Nestle, Flickr account. Image shared under CC license.

3) Roast and ground coffee (fluorescence microscopy image)

ground coffee, fluorescence image — Ever wondered what your coffee looked like when magnified many times? This image using fluorescence microscopy is of roasted coffee. Note the similarities between this image and the following one (which has a scale bar). Image shared under CC license from Nestle, Flickr

3b) More ground, roasted coffee, this time from Zeiss

Zeiss roast coffee — Scanning electron microscope image of roast (and ground) coffee magnified 750x. Image from Zeiss, Flickr, Todd Simpson, UWO Nanofabrication Facility. Shared under CC license. (To put the scale bar in perspective, it is the size of the smallest particles in an espresso grind. Clearly, the grind here is quite coarse).

4) Finally, an image of tea, just to keep this article tea-coffee balanced:

Green tea under the microscope — Green tea as seen under the microscope by the scientists at Nestle. Shared under CC license Nestle, Flickr.

If you come across any great images of coffee (or tea) under the microscope, please do share them. In the meanwhile, enjoy your coffee however you brew it.