Coffee Tips
Measurements and variables of espresso
Measuring a good espresso is incredibly hard for two reasons:
1. What a good espresso looks and tastes like is highly subjective.
2. There are many, many variables to espresso extraction.
There are some universally accepted rules and then there are many variables outside of those rules where professional the world over differ in opinion.
The rules that seem to be accepted the world over are:
- Your dose of ground coffee should be between 17 - 23 grams
- Your spent coffee cake should not be very muddy or alternatively rock hard
- When dosing consistently you should pour an espresso to achieve a volume of 20 - 30mls including crema (at Belaroma we say 30mls including crema)
- When dosing consistently you should adjust your grind to achieve this volume including crema in 20 - 35 seconds (at Belaroma we say 25 - 35 seconds)
- Your group heads and group handles should be kept thoroughly clean at all times
- Your group handle should be kept clean (cleaning hourly with blind filter and scrubbing handles and with an espresso machine cleaner at the end of every day), hot (always leave the group handle in the group head) and dry (use a t towel to thoroughly clean and dry before dosing)
- Your coffee should be ground immediately before brewing (Grinding On Demand)
- When you insert the group handle to the group head to brew a fresh espresso you must hit the brewing cycle immediately.
- The brewing temperature of the water passing through the ground coffee should be between 92 - 96 degrees celcius.
Many other espresso variables that are constantly discussed and debated are:
- Roast colour/time/profiles
- Which processing methods are best for espresso coffees
- Water quality TDS (Total Dissolved Solids) and Grains of Hardness
- Pump pressure
- Flow rate
- Should brewing temperatures outside of 92 - 96 degrees celcius be used
- Conical grinder blades or flat grinder blades plus the many other variables of grinders