Name the quantities before changing them
Dose is the mass of dry coffee. Brew water is the water introduced during brewing. Beverage yield is the drink collected in the cup or server. They are different measurements: wet grounds retain liquid, and some brewing methods add water after extraction.
A filter recipe written as 1:16 here means one gram of dry coffee for sixteen grams of brew water. An espresso recipe written as 1:2 means one gram of dry coffee for two grams of beverage. Always check which convention a recipe uses.
| Example | Calculation | Meaning |
|---|---|---|
| 20 g coffee at filter ratio 1:16 | 20 × 16 = 320 g | 320 g brew water, not a promise of 320 g drink. |
| 18 g coffee at espresso ratio 1:2 | 18 × 2 = 36 g | 36 g beverage output. |
| 60 g coffee per 1,000 g water | 1,000 ÷ 60 ≈ 16.67 | Approximately 1:16.67 by input mass. |
Two measurements describe different things
Beverage TDS is a measure of dissolved-solids concentration, usually expressed as a percentage by mass. A reading of 1.3% means roughly 1.3 g of dissolved material in 100 g of that measured beverage. This does not tell you which flavor compounds are present.
Extraction yield estimates the dissolved coffee mass as a percentage of the dry dose. You cannot measure it by tasting sourness or by timing a brew. Coffee refractometer measurements require the instrument's sampling and calibration procedure; a household water-conductivity meter does not supply coffee TDS.
Measure plain brewed coffee before adding milk, sugar or syrup. Their dissolved material would be counted in a TDS reading but did not come from the dry coffee dose. Adding plain water is a different case: record the new beverage mass and measure the diluted sample consistently.
Work through 20 g in, 300 g out
Suppose you brew 20 g dry coffee and collect 300 g of beverage. A suitable, calibrated coffee refractometer gives a representative TDS reading of 1.3%.
Estimated dissolved mass in the collected drink = 300 × 0.013 = 3.9 g. Estimated extraction yield into that drink = 3.9 ÷ 20 × 100 = 19.5%. The compact formula is extraction % = TDS % × beverage mass ÷ dry dose.
This is a mass-balance example, not a target or a taste verdict. It assumes the reading represents the beverage, uses consistent mass units, and does not separately account for dissolved material in liquid left behind with the grounds. Immersion methods and espresso sampling need particular care.
Use the extraction calculator with your own suitable measurements, or plan dose and water with the brew planner.
Dilution changes strength without extracting more coffee
Now add 100 g water to that 300 g beverage after separating it from the grounds. You still have about 3.9 g of extracted material, spread through about 400 g drink.
The new concentration is 3.9 ÷ 400 × 100 = 0.975% TDS. The estimated extracted mass remains 3.9 g; the dry dose remains 20 g. Adding this bypass water has made the drink less concentrated without extracting more material from the grounds.
This is useful when you enjoy the flavor balance but want a lighter drink. Pouring an additional 100 g through the grounds is a different experiment: it can dissolve more coffee while also increasing beverage mass. Both extraction and strength may change.
To make the distinction concrete, imagine a second brew with the same 20 g dose but 420 g brew water instead of 320 g: input ratio 1:21 rather than 1:16. Suppose it yields 400 g beverage measured at 1.10% TDS. That would contain 4.4 g dissolved material, giving 22% estimated extraction. Compared with the first brew, strength has fallen from 1.30% to 1.10% while extraction has risen from 19.5% to 22%. These are invented, internally consistent measurements for learning the arithmetic, not a predicted result from adding 100 g water; real results must be measured.
Change one useful variable
A finer grind exposes material differently and changes how water flows. In a percolation brewer it can also slow drainage or encourage uneven paths through the bed. More contact time is therefore not automatically better extraction.
Use taste and repeatability together. If a drink feels too concentrated but otherwise pleasant, test dilution. If it tastes thin and lacks flavor, check dose and ratio. If it is sharply sour and running unusually fast, try a small grind adjustment while holding dose and yield constant. Mixed sour, bitter, and drying sensations deserve a check for uneven brewing, residue, or a roast you do not enjoy.
- Record coffee, dose, water or beverage yield, grinder setting, temperature, time and a short taste note.
- Pick one change and write the expected effect before brewing.
- Repeat with everything else as consistent as practical.
- Keep the change only if the new cup is more enjoyable or more repeatable.
Temperature works with the rest of the recipe
A controlled drip-coffee study compared 87, 90 and 93°C while adjusting other variables to hold strength and extraction fixed. It found little remaining sensory effect of temperature within those conditions. That is evidence about an interaction, not proof that brewing temperature never matters.
Use a recipe temperature as a starting condition, and account for the brewer, preheating, roast and batch size. Water boils at a lower temperature at higher altitude; an unattainable number on a sea-level recipe should not become a rule. Near-boiling water is not inherently forbidden for all coffee, and brewing temperature is different from a comfortable drinking temperature.
Evidence: Controlled drip-brewing temperature study · IARC: very hot beverages
Choose the next useful check
If the same coffee changed when your water changed, use the water testing guide and mixing calculator. If taste and flow are the observation, use the conditional troubleshooter before inventing an extraction measurement.
Sources & limitations
This guide combines source-based explanations and practical starting points. Coffee Jacob has not performed hands-on product testing or controlled tasting trials for this guide. Source check: 13 October 2026.