Last updated: July 14, 2026
This page explains where the numbers in the extraction calculator come from, so you can judge how much weight to put on them.
What the calculator does
You give it a brewing method, a water temperature, and a grind size. It returns a target extraction time and a dissolved-solids range that, in our testing, lands in balanced territory: past the sour end of under-extraction, short of the bitter end of over-extraction.
The test protocol
- Parameters were swept rather than sampled once: water temperature from 65 to 95 C, grind settings across the usable range of each grinder, and bloom phases varied independently.
- Coverage spans 8 brewing methods, from immersion (French press, cold brew) to percolation (V60, Chemex, Kalita) to pressure (espresso, Moka pot, AeroPress).
- Grind size is anchored to specific grinders – Baratza Encore, Wilfa Svart, Fellow Ode – because a setting number does not transfer between machines.
- More than 50 origins were run through the protocol, since density and roast level shift how a bean gives up its solubles.
What the numbers are, and are not
They are a starting point that gets you close on the first attempt instead of the fifth. They are not a guarantee. Your water chemistry, your burr wear, the age of your beans, and the altitude you brew at all move the target, and no calculator can see those. Treat the output as the middle of a range to dial around, not as a verdict.
Caffeine timing
The caffeine timing tool is modeled on published half-life data and on CYP1A2 metabolism, which is where most of the variation between people comes from. Fast and slow metabolizers can differ by hours, so the tool gives you a window rather than a single time. It describes what the literature reports; it is not medical advice.
Revisions
As more lab batches are published, these ranges tighten. When a range changes, this page and the affected guides change with it, and the update date at the top moves. If your results consistently fall outside a published range, tell me through the contact form: that is data, and it is useful.