About BrewLab
BrewLab is an independent reference and tool project for people making coffee at home. Its purpose is simple: help you choose a recipe, measure what happened and find your way back to a cup you enjoyed.
A useful coffee tool should explain its numbers. A useful brewing record should preserve what you actually did. BrewLab connects the two, with guides that distinguish recipe suggestions, arithmetic and observations.
A place to start, and a reason to return
- New to brewing? Follow a guided V60, Chemex, upright AeroPress or French press recipe. See added and cumulative water weights, use the timer and record how the cup tasted.
- Making your everyday coffee? Keep a recipe in My brew journal, record actual measurements and reuse it. The bean library connects each bag to your recipes and tracks measured stock.
- Exploring the variables? Compare two saved cups, use taste troubleshooting to plan one next experiment, or follow an original A/B experiment protocol.
What you can use here
The site brings together 30 calculators, timers and reference tools, 20 practical articles, and six original experiment plans. Tools are grouped into brewing, espresso, reference guides and coffee utilities.
The journal, bean library, guided brewing and troubleshooting features connect these resources into a repeatable routine. A saved brew keeps its own recipe snapshot, so editing a recipe later does not rewrite earlier records. Saving a brew deducts beans only when you explicitly confirm it; you can also edit the measured stock in the bean library.
How we approach calculations and guidance
Calculator pages explain their input units, worked examples and important assumptions. A ratio calculation is different from a taste prediction: 20 g coffee at 1:16 needs 320 g input water, but that arithmetic does not determine the collected beverage mass or whether you will enjoy it.
Examples and automated checks help verify supported calculations and input handling. They do not establish that every equipment combination or physical brewing result has been tested. Displayed values may be rounded; measured inputs and model assumptions still matter.
Articles and guides link to relevant background references where appropriate. Editorial comparison ranges, starting recipes and experiment step sizes are identified as such. Manufacturer instructions, basket capacity, water suitability and safe handling remain specific to your equipment and situation.
Plans, observations and results are different
The home brew lab provides six independently written protocols covering grind, water ratio, temperature, pouring pattern, espresso yield and blind tasting. Each describes what to change, what to hold consistent, what to record and what the comparison cannot establish.
These are experimental plans, not reports of physical tests performed by BrewLab. Their example recipes are starting conditions, and their recording sheets leave observation cells blank. Creating A/B recipes does not create tasting results or deduct beans.
Your enjoyment ratings describe your preferences. A side-by-side comparison or troubleshooting suggestion is a hypothesis to investigate, not a statistical conclusion, professional grading decision or guaranteed improvement. BrewLab is not affiliated with or certified by the Specialty Coffee Association; the legacy cupping practice tool is separate from current Coffee Value Assessment methods.
Your records stay in your browser
No account is required, and the tools and journal features are free to use. Calculations run on your device after the page and its modules load. Opening a new page or reloading offline is not guaranteed; BrewLab does not install an offline app.
Recipes, brew snapshots and bean bags are saved in this browser for this site address when you select Save. There is no cloud sync or account recovery. A different browser, device or address uses separate storage, and clearing site data may erase records. Export a JSON backup to keep your work and import it on another device.
Local processing does not mean there are no network requests. Hosting and external fonts can process technical connection information, and advertising may be introduced. The privacy policy explains the processing and available choices; the terms describe the service’s scope and limits.
Corrections and questions
If a result or explanation seems wrong, use the contact page to prepare an email draft. Include the page address, input values and units, the result shown, what you expected and any supporting reference. For a display or timer problem, add the browser and a short description of the steps that led to it.
The contact page only prepares or copies your draft. You must send it yourself through your email application; copying is not confirmation that a message was received. Avoid passwords and unnecessary personal information.
For common questions about units, timers, local storage or experiment limits, start with the FAQ. For your next cup, choose a tool or a brewing path.
Page updated: November 5, 2026.