COFFEE DATA SCIENCE
The Coffee Sneeze in Espresso
Fines at the Start of an Espresso Shot
I noticed something in my espresso videos recently as I have been pulling more staccato shots. It seemed like steam or something was blowing in front of the camera for a split second at the very beginning of the shot. I investigated because I was worried about a leak in my machine, and I found out it wasn’t steam; it was coffee.
When pressure was first applied during pre-infusion, a small flurry of fine coffee blew into the cup.
Let’s zoom in on the bottom of the cup.
This tiny bit of evidence shows the air pushed out from the top of the puck forces a small amount of coffee out.
So I wanted to measure the total amount coming out with a quick experiment:
Less than 0.01g of coffee came out. It was not detectable with my Acaia Pyxis scale.
This coffee sneeze happens for staccato shots frequently, at least with a lever machine like the Kim Express where the pressure goes from zero to 2 bars almost instantly. This doesn’t happen as much for regular shots (non-staccato), or it is harder to see. However, I’m curious how the air being pushed through grounds affects the distribution inside the puck.
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Further readings of mine:
Collection of Espresso Articles
A Collection of Work and School Stories
A Summary of the Staccato Lifestyle
Measuring Coffee Grind Distribution
Espresso Baskets and Related Topics
