Coffee Data Science
4D CT Scans of Espresso Brewing
A truly inside look at coffee
Fraunhofer IIS Development Center X-ray Technology (EZRT) recently published some research on espresso using a 4D CT scanner. They were kind enough to share the data with me, so I had cut the data a few ways to understand what was going on.
They built a setup with an espresso machine and a CT scanner that would spin around the machine during the shot.
Then they would generate a 3D scan over time at 1 hz, so 4D.
This data is complex and difficult to wrap one’s head around it. So I looked a few vertical slices to look at the middle and sides of the puck. The scan reveals the initial flow of water. Once the puck is saturated, no more information is available.
The puck is slightly uneven in flow because the machine itself was slightly not level.
They also looked at a fine grind and a coarse grind. Both seemed to have water flow through initially at a similar rate.
Another view is vertical slices from the top. This shows how uneven the water flow is from the shower screen. However, the water flow generally normalizes, but there does seem to be some general unevenness that results in water coming down in the center of the puck by the end.
I tightened up this evaluation on the top of the puck. The challenge is that at the #1 level, it represents the air gap between the top of the puck and the shower screen. This does show the water streams down unevenly. This could be the shower screen or grouphead, and this might be a good reason to have a small amount of headspace between the puck and the shower screen.
Another way to view the data is to take the average of each plane and look at that value over time and depth.
This type of exploration is so compelling considering that the inside of the coffee puck is not easily observed. We can only see the output and the aftermath, but this technology allows us to peak into the inside of the mystery of espresso.
If you like, follow me on Twitter, YouTube, and Instagram where I post videos of espresso shots on different machines and espresso related stuff. You can also find me on LinkedIn. You can also follow me on Medium and Subscribe.
Further readings of mine:
My Second Book: Advanced Espresso
My First Book: Engineering Better Espresso
