Cupping With Your Z2

Cupping is the standard way roasters, buyers, and coffee lovers taste coffees side by side. Every bowl is brewed the same way, so the only difference you taste is the coffee itself. Your Z2 makes an excellent cupping grinder because its zero point and dial give you the same grind every time.

Credit: The cupping steps and scoring system below are adapted and summarized from Barista Hustle Cupping Protocols: A New Scoring System for Coffee, published by Barista Hustle (baristahustle.com). The protocol, scoring system, and scoresheet belong to Barista Hustle. Zerno is not affiliated with Barista Hustle. The Z2 grind settings are Zerno's own recommendations.

Z2 settings for cupping

600µm is a starting point, not a requirement. Barista Hustle recommends a grind that brings your best coffees to about 1.4% total dissolved solids (TDS) after 8 minutes. If you have a refractometer, adjust from 600µm until you land there. Without one, go finer if the cups taste thin and sour, and coarser if they taste heavy, bitter, or drying. Once you find your setting, note it and use it for every cupping. Keep the RPM at 1200 for every sample so speed never becomes a variable between bowls.

Burrs: any set works, but filter-focused burrs such as ULF, Brew, or Lab Sweet give the clearest read on each coffee (see Choosing Burrs for Your Z2). Set your zero point before you start so the dial numbers stay consistent session to session (see Setting the Zero Point on Your Z2).

What you need

Cupping bowls that hold 150 to 200ml, a scale that reads to 0.1g, a kettle, a timer, cupping spoons, a cup of hot rinse water for the spoons, and your Z2. A thermometer and refractometer are helpful but optional.

Step 1: Set up the table

1. Pick up to 12 coffees. More is possible for quick go/no-go checks, but 12 keeps your palate sharp.
2. Prepare 2 to 6 bowls of each coffee. One bowl per coffee is enough for a roast check.
3. Use a ratio of 55 grams of coffee per liter of water: 10g of coffee to 180ml of water per bowl.
4. Make sure the bowls are clean, dry, odorless, and at room temperature.
5. Label each sample on the underside of the bowl so you can shuffle the order and taste blind.

Step 2: Grind

1. Set your Z2 to your cupping grind (start at 600µm).
2. Purge between coffees. Hold the switch down for Purge Mode and tap the chute knocker to clear the chamber, then grind a few beans of the next sample and discard them before weighing out the real dose.
3. Grind 10g for each bowl and check every bowl on the scale. Aim for 10g plus or minus 0.1g.
4. Line up the bowls on the table in order.

Step 3: Pour

1. Start a timer and pour water just off the boil into each bowl, weighing to 180g plus or minus 2g. Barista Hustle recommends clean, odorless water with a pH between 7.0 and 7.4 and buffer (alkalinity) no higher than 70ppm.
2. Pour at a steady pace of about three bowls per minute, spending the same time on each bowl.

Step 4: Break and skim

1. At 5:00, break the crust of the first bowl with four stirs of the spoon, reaching all the way to the bottom. This is the best moment to smell the wet aroma.
2. Break each bowl in the same order and at the same pace you poured. Rinse your spoon in hot water between bowls.
3. Skim the foam and grounds off the surface of each bowl, again in the same order and at the same pace.

Step 5: Taste

1. Optional: at 8:00, draw a small sample (about 5ml) from 1cm below the surface of each bowl for a TDS reading later.
2. Start tasting once the coffee drops below 65°C, usually around 10 minutes.
3. Slurp each coffee at three temperatures: hot (about 65°C), comfortable (about 55°C), and warm (about 45°C). Many qualities, especially sweetness, show up differently as the coffee cools.
4. Record your notes and scores as you go.

Scoring the coffees

Barista Hustle's system scores ten categories, each out of 10, for a total out of 100. Each category is scored from 7.5 to 10 in steps of 0.1.

A few rules of thumb from the protocol: higher scores reward intense, complex, positive qualities. A score above 8.0 in a category means negative traits are mostly absent, and a score below 8.0 means some are present. A score below 7.5 in any category disqualifies the coffee. Specialty coffees are expected to total above 80. There is no separate "overall" score; balance captures how everything works together.

For the full scoring descriptions and the printable scoresheet, see Barista Hustle Cupping Protocols at baristahustle.com.

Tips for Z2 owners

Clean between sessions, not between bowls. Purging between coffees is enough during a cupping. Give the Z2 a full clean afterward if you cupped many coffees (see Opening, Cleaning, and Closing Your Z2).

Season new burrs first. Fresh burrs change character over their first kilograms. If your burrs are new, season them before you rely on your cupping results.

Keep this guide Z2-specific. Dial settings and burrs differ between the Z1 and Z2, so use this article only for the Z2. Z1 owners, see Cupping With Your Z1.

Questions about dialing in your Z2 for cupping? Email info@zerno.co.

Cupping protocol and scoring system adapted from Barista Hustle Cupping Protocols: A New Scoring System for Coffee, © Barista Hustle (baristahustle.com).