What is CaffiLab?
CaffiLab is a scientific caffeine estimation tool that calculates how much caffeine is in your coffee based on your exact brew parameters — not generic averages from a database. It uses a model grounded in extraction science:
C = dose × caffeine fraction × recovery
Instead of telling you "a cup of coffee has 95 mg," CaffiLab accounts for your specific coffee dose, bean species, brew method, grind size, water temperature, brew time, and more.
Getting started: the basic inputs
When you open CaffiLab, you'll see six basic inputs that drive the core estimate:
1. Brew method
Select your brewing method — pour over, espresso, French press, cold brew, AeroPress, drip machine, Moka pot, Turkish, Indian filter, or others. This sets sensible defaults for grind size, brew time, temperature, and extraction expectations.
2. Bean species
Choose between Arabica, Robusta, Blend, or "Not sure." Robusta contains roughly 2.2% caffeine by weight versus Arabica's 1.2%, so this choice has a large impact on the estimate.
If you select "Not sure," CaffiLab will use package clues and price to infer a likely blend profile.
3. Coffee dose
Enter the weight of dry coffee grounds you're using. CaffiLab supports grams, ounces, and pounds. More coffee means more available caffeine — this is a direct multiplier in the formula.
4. Brew water
The volume of water you're brewing with. This determines your coffee-to-water ratio, which affects extraction efficiency. CaffiLab shows your current ratio and the method's target ratio.
5. Beverage volume
The final volume of liquid in your cup, including any dilution. This affects concentration (mg per 100 ml) but not total caffeine.
6. Brew time
How long water is in contact with the coffee grounds. Longer contact generally increases caffeine extraction, though the relationship plateaus.
Understanding the results
CaffiLab shows four key outputs:
- Estimated caffeine (mg): The headline number — total milligrams of caffeine in your cup.
- Confidence label: Very High, High, Medium, or Low — based on how many inputs you've declared and how far your recipe deviates from method defaults.
- Precision bar: A visual gauge showing how tight the estimate is.
- Range: The lower and upper bounds (e.g., 140–180 mg), reflecting the uncertainty percentage.
Fine-tuning with advanced inputs
Click Advanced inputs to reveal 10+ additional parameters:
- Grind size: Finer grinds expose more surface area, increasing extraction.
- Roast level: Light roasts can yield slightly more caffeine in comparable brews than very dark roasts.
- Temperature: Higher temperatures increase extraction rate. Cold brew uses room-temperature water over many hours.
- Extraction yield: If you measure TDS (total dissolved solids), entering yield is one of the strongest ways to calibrate the estimate.
- Pressure: Only for espresso — 9 bar is the reference point.
- Water minerals and pH: Balanced mineral water is closest to specialty brewing standards.
- Bean freshness: Very fresh beans can resist even extraction; stale beans extract less predictably.
- Filter type: Paper filters produce a slightly cleaner brew; metal filters retain more material.
- Chicory: For Indian filter coffee — chicory adds body but no caffeine.
Each input you declare reduces the uncertainty range, improving confidence.
Tips for accurate estimates
- Weigh your coffee. Scoops vary; a kitchen scale makes the dose precise.
- Measure your water. Know how much water goes in and how much beverage comes out.
- Time your brew. Especially for immersion methods like French press and cold brew.
- Start with defaults. CaffiLab auto-fills sensible values. Adjust only what you know.
- Check the explanation panel. As you interact with each field, CaffiLab explains what it does and how it affects the estimate.
A note on accuracy
CaffiLab is an estimation tool, not a laboratory instrument. Actual caffeine content varies with cultivar, growing conditions, roast batch, water chemistry, and brewing geometry. The model is calibrated against published extraction research and aims to give you a useful, directionally accurate number — not a precise chemical measurement.
For most practical purposes — understanding whether you're having 100 mg or 300 mg, comparing brew methods, or tracking daily intake — CaffiLab gives you a much better answer than generic tables.