P 3.06 – Glossary and Recap

Recap and Glossary

Recap

• Darcy’s law describes the decrease in flow rate as the coffee bed depths increase,
• For this reason, we tend to grind coarser for larger brew volumes.
• E.E. Lockhart (the architect of the Coffee Brewing Control Chart) recommends using a coffee depth of between 1–2 inches (≈ 2.5 and 5 centimetres)
• There is a lot of potential to lose heat from the air-water interface at the top of the slurry. Evaporative cooling is accelerated by moving air so we recommend you avoid placing ventilators directly above your brewbar.
• Air velocity of up to 3 meters (about 10 feet) per second can double the rate of evaporative cooling.