AGITATIVE
Better coffee at home — brew methods, ratios, and the craft behind a great cup.
From dialing in a brew ratio and picking a grind size to timing a bloom and pour, checking your extraction, and estimating caffeine, Agitative pairs free hands-on brewing calculators with practical guides and a richly illustrated museum. Better coffee, one variable at a time.
Coffee Brewing Calculators
Free tools for the home barista — coffee-to-water ratio calculator, grind size guide, brew timer, TDS & extraction yield calculator, caffeine estimate calculator, and a bloom timer.
Coffee-to-Water Ratio Calculator
Solve any brew ratio from any two values — dose, water, or ratio — with quick presets for espresso, moka pot, French press, pour-over, auto-drip, and cold brew.
Grind Size Guide
Pick the right grind for your brew method and get its particle-size range in microns plus a typical brew time.
Brew Timer
Build a bloom-and-pulse pour-over schedule from your dose and ratio, with cumulative water targets and timestamps.
TDS & Extraction Yield Calculator
Turn a refractometer TDS reading into Extraction Yield using the SCA brewing-control formula, and see it against the 18-22% gold-cup range.
Caffeine Estimate Calculator
Estimate the caffeine in your cup from the dry coffee dose, with a realistic range rather than a false-precision single number.
Bloom Timer
Get a bloom water amount and recommended bloom time, adjusted for how many days your beans have been off roast.
Museum of Coffee
Wander an immersive collection built entirely from Wikipedia and Wikimedia Commons — the origins of coffee across the regions and legends that carried it around the world, the brewing devices from espresso machines to moka pots, Chemex, and siphons, the coffee plant itself and its relatives, and the cafés and coffeehouse traditions that grew up around the cup, each in its own gallery.
Tour the museum →From the Journal
Guides on brew ratios, grind size, extraction and TDS, caffeine, and choosing between espresso, moka pot, Chemex, and siphon brewing.
The Coffee-to-Water Ratio Explained: How to Dial In Every Brew Method
What a 1:16 ratio actually means, why it's the single biggest lever on strength, and how to pick a starting ratio for espresso, moka pot, French press, pour-over, drip, and cold brew.
A Complete Grind Size Guide: Matching Your Grinder to Your Brew Method
Why grind size has to match contact time, what happens when it's wrong in either direction, and a method-by-method reference from Turkish coffee's near-powder to cold brew's extra-coarse grounds.
How to Bloom Coffee Properly (And Why It Matters)
The science behind the first small pour in pour-over brewing, why fresher beans need a longer bloom, and how to tell when the bloom has actually finished doing its job.
TDS and Extraction Yield: What Every Home Barista Should Know
How a refractometer reading becomes an Extraction Yield percentage, what the SCA's 18-22% gold-cup range means in practice, and how to use both numbers as a diagnostic rather than a rulebook.
How Much Caffeine Is Really in Your Coffee?
Why brewing method matters less to total caffeine than most people assume, why a small espresso shot and a big drip mug can land in a similar range, and why any estimate should be treated as a range, not a precise figure.
Espresso vs. Moka Pot vs. Chemex vs. Siphon: Choosing a Brew Method
A side-by-side look at four very different ways to make coffee — pressurized espresso, stovetop moka pot, gravity-fed Chemex, and the theatrical vacuum siphon — and what each one is actually good at.
Keep Learning
Plain-language explainers on the fundamentals of brewing, the equipment behind every method, the science of caffeine and extraction, and the culture and history that built coffee into a daily ritual worldwide.
Visit the Learn hub →