Dosing

The process by which we measure coffee dispensed from a grinder into a portafilter basket is dosing. It’s critical that baristas approach dosing with care, since the quality of beverage is not only hugely dependent upon the correct volume of ground coffee, but also the even distribution and compaction of those grounds within the portafilter basket. To account for the latter, we use a distribution technique to level and evenly disperse ground coffee in the basket before tamping and brewing.

Dosing techniques vary slightly depending upon the grinder used in preparation. Largely, we’ll encounter grinders that have a dosing chamber, which helps to prevent clumps and distribute an even amount of ground coffee. In some instances the dosing chamber delivers coffee from directly above the portafilter basket. This isn’t typical found in commercial grinders, but an example is the Mazzer Robur. More often, you’ll encounter a doser that distributes coffee into the basket via angled slide. When this is the case, we use a “sprinkler action” (i.e., move the portafilter handle from side to side) to ensure even dosing.

Compression

Since the dosing chamber of a grinder dispenses grounds using gravity (i.e., dropping them into the basket), some air will be present between ground coffee particles. While not universally practiced, one way to remove air and settle the coffee bed is to knock the portafilter against the grinder fork. In doing so, the coffee will level somewhat and settle further down into the basket. It is thought that this practice helps prepare the coffee for distribution and tamping, and leads to a more even, repeatable espresso extraction.

Grooming

After dosing and before tamping, you must groom the dose. When grooming, you are redistributing ground coffee in order to:

• Ensure equal distribution throughout the top layer of the coffee bed
• Eliminate extra, undesired coffee grounds (if the dose is too large)
• Polish the surface of the coffee bed before tamping

There are several methods of grooming, including NSEW, Stockfleth’s Move and the Weiss Distribution Technique. For the sake of training – and your sanity – we will cover only NSEW here. This method is easy to learn and execute quickly and with consistency.

When performing the NSEW, or North South East West, grooming technique, use a straight index finger to push the mound of coffee grounds from the bottom toward the top rim of the portafilter basket (i.e., from “south” to “north”) without pushing the grounds over the rim of the basket. Push the grounds from the top of the portafilter basket back down toward the bottom (i.e., from “north” to “south”). Perform the same maneuver from left to right, and then right to left (i.e., “east” to “west”) before finally pushing any remaining, excess grounds over the rim of the basket and into a knock box or other receptacle.

If performed correctly, the surface of the coffee bed should be smooth and level. In an ideal scenario, there is no excess coffee remaining from the dose.

Step-by-Step Guide to Dosing and Grooming

1. Unlatch the portafilter from the espresso machine
2. Knock out the spent puck
3. Wipe the inside of the portafilter basket with a dry rag
4. Ensure all basket holes are clear
5. Begin grinding while the portafilter is beneath the dosing chamber
6. Rotate the portafilter to ensure grounds fill the basket evenly
7. Turn off the grinder (not necessary if used a timed dose)
8. Compress the grounds by knocking the portafilter against the grinder fork (if desired)
9. Groom the coffee bed for even extraction

At this point, you are ready to begin tamping.