Coffee Extraction Yield Calculator

Extraction Snapshot

{{ tdsDisplay }} · {{ solidsDisplay }} dissolved solids from {{ doseDisplay }} dry coffee

{{ extractionStatus.label }} {{ strengthStatus.label }} {{ profileLabel }} {{ beverageRatioDisplay }} Retained liquid included

Brew profile:

Pick the closest brew style; choose Custom if your lab or roaster uses its own target box.

Dry coffee dose:

Use the dry coffee weight in grams, such as 20.0 g filter or 18.0 g espresso.

Beverage mass:

Weigh the brewed beverage after filtering, including any bypass water already mixed into the cup.

Refractometer reading:

Enter the cooled, filtered sample reading. The calculator auto-recomputes as you type.

Target aim:

Use center for normal QC, or bias lower/upper when intentionally chasing a lighter or richer cup.

Measurement notes

{{ warning }}

Taste cue:

Optional: add the sensory direction after tasting so the next-brew note is less generic.

Bypass water already mixed:

Leave 0 unless the measured beverage includes water added after extraction.

Retained liquid estimate:

Keep 0 for the standard cup-yield formula, or enter estimated trapped brew liquid.

Reading correction:

Use 0 for a calibrated meter; apply only a known lab offset.

points

Brix to TDS factor:

Keep your meter or lab factor. A common coffee starting point is near 0.85.

Custom extraction band:

Enter lower and upper extraction targets in percent.

low % high %

Custom TDS band:

Enter lower and upper strength targets in % TDS.

low %TDS high %TDS

Metric	Value	Detail	Copy
{{ row.metric }}	{{ row.value }}	{{ row.detail }}

Signal	Status	Next check	Copy
{{ row.signal }}	{{ row.status }}	{{ row.next }}

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Coffee extraction yield is the percentage of dry coffee that dissolves into the finished drink. Strength, usually read as total dissolved solids (TDS), is the concentration of those dissolved solids in the cup. A brew can be strong but poorly extracted, well extracted but dilute, or balanced by the numbers and still need a taste check.

The measurement matters most when a recipe is being repeated or adjusted. A filter brew made from 20 g of coffee and 320 g of beverage at 1.35% TDS contains 4.32 g of dissolved solids, so the cup extraction yield is 21.60%. That result says the dose gave up a measurable share of soluble material, while the TDS tells you how concentrated the drink is after that extraction reached the cup.

Brew control map with extraction yield on the horizontal axis, strength on the vertical axis, a current point, and a selected target band. — Strength and extraction yield are read together on a two-axis brew map.

Brewing-control charts traditionally place strength on one axis and percent extraction on the other. The center of that chart is useful for quality control, especially for filter coffee, but it is not a universal taste law. Roast level, grind distribution, water, brewer shape, contact time, and personal preference can all move a cup away from a textbook center while still making sense.

Extraction yield is best used as a repeatable measurement, not as a final verdict. It helps compare two brews, catch a likely scale or refractometer error, and decide whether the next change should be about extraction, strength, or sample handling before another cup is brewed.

Technical Details:

Percent extraction is a mass-balance calculation. TDS estimates the concentration of dissolved coffee in the beverage. Beverage mass turns that concentration into grams of dissolved solids, and dry dose supplies the denominator for yield. When the same dose produces more dissolved solids in the finished cup, cup extraction yield rises.

A coffee refractometer reports either coffee TDS directly or a Brix-style reading that needs a conversion factor before it can be used as a TDS estimate. The calculator applies the Brix factor only when the Brix scale is selected, then adds any documented reading correction in percentage points. The effective TDS value is capped at 35% to prevent impossible entries from dominating the output.

Bypass water and retained liquid are accounting aids. Bypass water already mixed into the cup dilutes the final sample, so the page estimates the pre-bypass strength without changing the cup extraction yield. Retained liquid estimates dissolved solids still held in the bed or puck at the same measured strength, then reports a retained-liquid scenario separately from the primary cup number.

Formula Core:

The primary result is the cup extraction yield. Optional retained-liquid accounting creates a second scenario result, while bypass creates a strength estimate for the liquid before dilution.

\begin{array}{lcl} T & = & if Brix, (R \times F) + C; otherwise R + C \\ S & = & B \times \frac{T}{100} \\ E_{cup} & = & \frac{S \times 100}{D} \\ E_{retained} & = & \frac{(S + L \times \frac{T}{100}) \times 100}{D} \\ T_{pre-bypass} & = & \frac{S \times 100}{B - W} \end{array}

Coffee extraction yield symbol map
Symbol	Meaning	Source in the calculator
`R`	Raw refractometer reading	`Refractometer reading`, entered as `% TDS` or `Brix`.
`F`	Brix-to-TDS factor	`Brix to TDS factor`, used only for Brix readings.
`C`	Reading correction in percentage points	`Reading correction`, added after scale conversion.
`T`	Effective strength as % TDS	`Effective strength` and the vertical value on `Brew Control Map`.
`B`	Finished beverage mass in grams	`Beverage mass`, including bypass water already mixed into the cup.
`D`	Dry coffee dose in grams	`Dry coffee dose`, the denominator for extraction yield.
`S`	Dissolved solids in the cup	`Dissolved solids in cup`.
`L`	Retained liquid estimate in grams	`Retained liquid estimate`, reported as a separate scenario.
`W`	Bypass water already mixed in grams	`Bypass water already mixed`, used for `Pre-bypass strength estimate`.

Built-in coffee extraction and strength target bands
Brew profile	Extraction low	Extraction high	TDS low	TDS high	Status rule
Filter / pour-over	18.0%	22.0%	1.15%	1.45%	Inside the band when both values are greater than or equal to the low value and less than or equal to the high value.
Immersion / AeroPress	18.0%	22.0%	1.20%	1.55%	Below if the value is less than the low value; above if it is greater than the high value.
Espresso	18.0%	22.0%	8.00%	12.00%	Strength uses the espresso TDS band; extraction uses the same 18% to 22% window.
Concentrate / moka	18.0%	24.0%	3.00%	5.00%	Extraction has a wider upper limit to match concentrated brew profiles.
Custom target box	User set	User set	User set	User set	Reversed low and high entries are ordered automatically; very narrow bands trigger a warning.

Measurement warnings used by the coffee extraction calculator
Warning trigger	What to check
Dose, beverage mass, or refractometer reading is zero or below	The result is not ready until all three required measurements are positive.
TDS is outside the usual range for the selected profile	Confirm the reading scale, sample temperature, and whether the sample was filtered or cooled.
Brix factor is below 0.70 or above 1.00	Use the factor documented for the meter or lab method before trusting a Brix-based result.
Reading correction is more than 0.50 percentage points from zero	Confirm the offset came from a documented meter check, not from a taste adjustment.
Bypass water is equal to or greater than beverage mass	The pre-bypass estimate cannot be meaningful if dilution is as large as the finished drink.
Cup extraction yield is above 35%	Recheck TDS scale, dose, beverage mass, and any retained-liquid assumption.

The chart point, target aim, deltas, and table rows are deterministic outputs from these same measurements. They do not diagnose channeling, water chemistry, roast development, or sensory quality by themselves; they only place the measured brew against the selected extraction and strength bands.

Everyday Use & Decision Guide:

Start with the brew profile that matches the cup in front of you. Filter / pour-over is the best first pass for most low-strength brewed coffee. Use Espresso for shots with TDS in the high single digits or low teens, Concentrate / moka for stronger non-espresso brews, and Custom target box only when your shop, lab, or roaster has its own control limits.

Weigh the Dry coffee dose before brewing and the Beverage mass after brewing. Enter the cooled sample in Refractometer reading using the correct scale. If the meter reports Brix, check Brix to TDS factor before reading the result; the default 0.85 is a common coffee starting point, not proof that every meter uses the same calibration.

Use Target aim to compare the brew with the lower, center, or upper aim inside the selected band. This changes the delta target, not the measured extraction yield.
Add Taste cue after tasting so Next brew move can distinguish sour, bitter, weak, heavy, and balanced notes.
Enter Bypass water already mixed only when dilution happened after extraction and the measured sample includes that water.
Keep Retained liquid estimate at zero for the standard cup-yield formula. Add it only when an immersion or bed-retention scenario is useful.
Use Reading correction only for a known refractometer offset. It is not a way to force a number into range.

Read the Extraction Snapshot first, then open Extraction Ledger for the exact calculation. Taste Calibration Brief turns the extraction and strength status into a next-brew note. Brew Control Map plots the current brew, the selected target aim, the target band, and an optional retained-liquid scenario.

A result inside the target band does not mean the brew tastes good, and a result outside the band does not automatically mean the brew failed. If Measurement notes appears, fix the measurement problem before changing grind, contact time, dose, or dilution.

Step-by-Step Guide:

Use scale readings and a cooled refractometer sample before interpreting the status badges.

Choose Brew profile. Check that the summary badge shows the intended profile, such as Filter / pour-over or Espresso.
Enter Dry coffee dose and Beverage mass in grams. If either value is zero, Measurement notes reports that the value must be above zero and the result is not ready.
Enter Refractometer reading, then choose % TDS or Brix. For Brix, open Advanced and confirm Brix to TDS factor.
Set Target aim. Use center for routine quality control, lower for a lighter planned target, or upper for a richer planned target.
Open Advanced only for documented context: Taste cue, bypass, retained liquid, reading correction, or custom bands.
Read Extraction Snapshot. Check Cup extraction yield, Effective strength, and any warning badges before trusting the recommendation.
Use Extraction Ledger to audit the formula row, then use Taste Calibration Brief and Brew Control Map to decide one next change.
Open JSON only when you need a structured record of the inputs, target band, result fields, chart data, guidance rows, and warnings.

Interpreting Results:

The two fields to trust first are Cup extraction yield and Effective strength. Extraction yield says how much of the dose dissolved into the cup. Strength says how concentrated that cup is. The result is most useful when both values agree with taste and the warning list is empty.

How extraction and strength status combinations are interpreted
Status pattern	Common meaning	First check
`In extraction target` and `Strength in band`	The measured brew sits inside the selected control band.	Use `Taste cue` and repeatability before changing the recipe.
`Below extraction target` with `Low strength`	The cup often reads thin or under-developed.	Confirm the sample, then test finer grind, longer contact, or better wetting before raising dose.
`Below extraction target` with `High strength`	The cup is concentrated but did not dissolve enough from the dose.	Improve contact and flow rather than simply making the recipe stronger.
`Above extraction target` with `Low strength`	The brew is dilute but pushed far on extraction.	Tighten beverage yield while reducing extraction pressure.
`Above extraction target` with `High strength`	The cup is likely heavy, dry, or overdone if taste agrees.	Back off grind, contact, temperature, or agitation before adding dilution.

Boundary rules are exact. For the filter profile, Cup extraction yield from 18.00% through 22.00% is in target, while 17.99% is below and 22.01% is above. Effective strength from 1.15% through 1.45% TDS is in band for filter coffee.

False confidence is the main risk. A clean-looking In extraction target badge can still hide a hot, unfiltered, or poorly mixed sample. When the number surprises you, repeat the refractometer reading and compare Formula, Measurement repeatability, and Warnings before making the next brew.

Worked Examples:

Filter brew near the center

A 20.0 g dose, 320.0 g beverage, and 1.35% TDS sample under Filter / pour-over gives Dissolved solids in cup of 4.320 g and Cup extraction yield of 21.60%. The profile bands mark it as In extraction target and Strength in band. With center aim selected, Delta to target aim is +1.60 points EY and +0.05 %TDS, so taste decides whether the next brew should repeat or move lower.

Brix reading converted for a lighter filter cup

A 18.0 g dose, 270.0 g beverage, 1.45 Brix reading, and 0.85 factor gives Effective strength of 1.23% TDS. The cup contains about 3.328 g dissolved solids and reports Cup extraction yield of 18.49%. That sits barely inside the filter extraction band, so a sour taste cue would support a small extraction increase rather than a large ratio change.

Espresso with a normal extraction number

An 18.0 g espresso dose, 40.0 g beverage, and 9.00% TDS reading produces 3.600 g dissolved solids and exactly 20.00% Cup extraction yield. The espresso strength band is 8.00% to 12.00% TDS, so the output should show In extraction target and Strength in band. If the shot tastes harsh, the number does not rule out channeling, excessive fines, or a temperature problem.

Bypass and retained-liquid context

A 20.0 g brew with 340.0 g final beverage, 40.0 g bypass water, and 1.20% TDS contains 4.080 g dissolved solids, so Cup extraction yield is 20.40%. Pre-bypass strength estimate rises to 1.36% TDS because the same solids are assigned to the 300.0 g pre-bypass mass. If 10.0 g retained liquid is also entered, Retained-liquid scenario reports 21.00% EY, which is useful context but not the comparable cup-yield number.

Troubleshooting an impossible-looking result

A filter entry with 20.0 g dose, 300.0 g beverage, and 0.65% TDS gives only 9.75% Cup extraction yield and triggers a low-TDS measurement note for the profile. Before grinding finer, check whether the meter was set to Brix, whether the sample was hot or unfiltered, and whether the beverage mass was copied from brew water instead of the liquid in the cup.

FAQ:

What is the main formula?

The primary formula is beverage mass multiplied by effective TDS fraction, divided by dry coffee dose, then expressed as a percentage. The Formula row in Extraction Ledger shows the same substitution with your numbers.

Should I enter brew water or beverage mass?

Enter the finished Beverage mass in the cup. Brew water is not the same value because grounds and filters retain liquid, and this calculator's primary extraction result is based on the cup-yield formula.

Can I use a Brix refractometer?

Yes. Select Brix beside Refractometer reading, then confirm Brix to TDS factor. The calculator multiplies the Brix reading by that factor and then applies any reading correction.

Why did I get a warning even though the result appeared?

Warnings flag measurement conditions that can make a neat result unreliable, such as unusual TDS for the selected profile, a large reading correction, bypass water as large as the beverage mass, or an extraction yield above 35%.

Does retained liquid replace the cup extraction yield?

No. Retained-liquid scenario is separate context. Use Cup extraction yield for normal comparisons, then use retained liquid only when you want to estimate solids still trapped in the bed or puck.

Are my entries sent away for calculation?

There is no separate server calculation step for the coffee math. The page computes the result after it loads, and copied or downloaded CSV, DOCX, chart image, and JSON records are created only when you choose those actions.

Glossary:

Extraction yield: The percentage of the dry coffee dose that ended up as dissolved solids in the beverage.
Total dissolved solids: The concentration of dissolved coffee in the drink, reported as % TDS.
Dry coffee dose: The weighed coffee before brewing, used as the denominator for extraction yield.
Beverage mass: The finished liquid mass in the cup, including bypass water if it has already been mixed in.
Brix: A refractometer scale that the calculator can convert to a TDS estimate with a chosen factor.
Bypass water: Water added after extraction that dilutes the cup without adding dissolved coffee solids.
Retained liquid: Brew liquid estimated to remain in the bed or puck, used for a separate retained-liquid scenario.

References:

2017 SCA Certified Home Brewer Program Requirements, Specialty Coffee Association, 2017.
Towards a New Brewing Chart, Specialty Coffee Association.
Amped Up: Using Electricity to Detect and Quantify Molecules in Brewed Coffee, Specialty Coffee Association.
An Equilibrium Desorption Model for the Strength and Extraction Yield of Full Immersion Brewed Coffee, Scientific Reports, 25 March 2021.
Systematically Improving Espresso: Insights from Mathematical Modeling and Experiment, Matter, January 2020.