Targeting EY

• Lighter roasts: 19–23% EY
• Medium roasts: 17–21% EY
• Darker roasts: 15–19% EY

What sets the target EY

Determining the target EY is primarily based on the roast degree, and the production of fines should be counted as a factor shifting the target EY up or down (fewer fines raise the target EY).

Factors such as brew-only burr geometry, lower RPM, and lower feed rate are generally considered to reduce fines, and the opposite is also true.

Water for lighter roasts

Lighter roasts are better suited to relatively harder water (80–120 ppm), with KH at roughly 40–60% of the GH reading.

Dialing in

Once you set the target EY, adjust the grind setting and brew temperature to achieve the desired brew.

If you modify the textural characteristics, explore different extraction dynamics by changing the pouring speed (essentially combined with the grind setting), commonly described as percolation vs immersion—in other words, a finer grind with a higher flow rate / higher water level in the dripper vs a coarser grind with a slower flow rate / lower water level.

Comparing profiles

Make sure that the brew ratio and extraction yield are the same when comparing how different extraction dynamics affect the sensorial experience.