Tools needed:
- Graduated cylinder 100ml Class A Tolerance ±0.05ml
($10 on Amazon, or in NZ) - Scales, accurate to at least +- 0.1gms. (Acaia Lunar are awesome)
- An optional extra is a funnel to help you pour the beans into the cylinder – or you can use a barista jug.
- An optional extra is a short piece of 25mm dowel as a tamper.
- Roasted Coffee beans
Steps:
1. Place the empty 100ml cylinder on the scales and zero.
2. Fill the cylinder to near the 100ml line. Tap the coffee beans down, pack it level with something like a piece of dowel, or rolled up cardboard. The object is to get it level near the 100ml line, by adding coffee beans and packing it level. Read how many mls you have.
3. Then weigh the cylinder with the coffee beans. If this is a very light roast, the coffee beans will be relatively heavy, as much as 49gms. If your roast is very dark, the coffee beans will weigh a lot less, as little as 34gms.
4. We need the coffee bean density in g/ml, so divide the weight by the volume. For example 41.3/97= 0.425
This coffee bean density value tells you roughly where this coffee roast level falls on the spectrum. Enter this number in the search box at density.coffee to find the starting position for your extraction.
5. Taste the coffee. If it is sour, you have under extracted, add 20 and make it again. If it is bitter, you have over extracted, subtract 20 and make it again.
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