Clean, Hot, Dry
The Spent Puck
After you extract coffee grinds under pressure in a filter basket, the grinds are compressed into a shape that looks just like an ice hockey puck. Many baristas spend a lot of time analysing the spent puck of coffee. A puck that has obvious holes in it or is much thicker on one side than the other is evidence of a critical unevenness in the flow of water. However, not a great deal of useful information can be gleaned from looking at spent coffee grinds. You can learn much more by tasting coffees and watching for an obviously irregular flow of water during extraction.
The method of disposing of the puck should not consume a lot of time in a barista’s workflow. It is necessary to tap out the puck into a knock box: a tube or a bucket with a bar for knocking the portafilter across. This should be done firmly but not with excessive force. Knocking out the puck too firmly can dent the filter basket, and is noisy for your customers.
The Final Step
Disposing of the puck is the final step in one full cycle of espresso making. When you begin another cycle, it is best to return to the grinder with a clean and dry filter basket to dose the next shot. Baskets need to be dry wiped. This process does not require any cleaning agent or disposable wipe; an absorbent, washable material such as a cotton towel is best. If you use a brush rather than a towel, you will remove only coffee particles, leaving oil residue and moisture in the basket. Even if a basket appears clean, it should be wiped every time it is taken out of the machine in order to remove any condensation that may build up.
Every fifty cycles or every hour (whichever happens first) a full clean-down will be needed.