Brew Snapshot
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Pour schedule
Step Start End Addition (g) Cumulative (g) Copy
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Tasting cues

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Introduction

Coffee brewing is an extraction problem disguised as a daily ritual. The balance between coffee mass, water mass, contact time, and temperature decides whether a cup tastes thin, balanced, or dense, so small changes are easy to feel in the mug. This planner turns that balancing act into a brew plan you can weigh, time, and repeat.

Instead of starting from guesswork, the tool works backward from the beverage size you want to serve. It calculates how much dry coffee and total water are needed, estimates how much liquid the grounds will hold back, and lays the brew out as a bloom plus one or more pours. The result is a schedule you can take to the kettle, not just a static ratio.

That matters most when you move between brew styles. A 360 mL pour-over, a 36 mL espresso, and a one-liter cold brew concentrate do not share the same strength target or contact time, so the presets change ratio, brew time, retention, and expected strength band before you make custom adjustments.

A practical example is a morning filter brew for two small cups. Enter a 360 mL target, keep the pour-over preset, and the planner produces a coffee dose a little above 27 grams, about 420 grams of total water, and a timed pour sequence near the preset strength window.

The planner is still a starting model rather than a taste guarantee. It does not know your grinder alignment, roast age, water chemistry, or how evenly the bed drains. The numbers are most useful when you combine them with taste, drawdown time, and the actual water you pour.

Everyday Use & Decision Guide:

Start with the preset closest to the brewer on your counter, then leave the default ratio, brew time, bloom share, and retention alone for the first pass. That gives you a realistic baseline before you begin chasing taste with custom numbers.

  • This tool is a good fit when you know the beverage size you want and need a repeatable dose, water mass, and pour sequence.
  • If your information is rough, trust the preset first and change only one thing at a time, usually ratio or brew time, not every field at once.
  • A common misread is treating the requested beverage size as the same thing as kettle water. The planner separates total water from expected final yield because the grounds retain part of the brew.
  • Before trusting the recipe, compare the Brew Snapshot with the Recipe Breakdown and make sure the warnings area is empty.

The Brew Control Map is best read as a quick orientation, not a verdict on flavor. It compares your current ratio and estimated strength with the chosen preset's target band, so it shows whether the plan sits inside or outside that expected zone. Verify the plan by weighing both coffee and water and checking how close the real brew time lands to the planned one.

Technical Details:

The planner models four linked quantities: coffee dose, total brew water, retained water in the grounds, and estimated beverage strength. It starts from your target beverage size, then asks how much coffee is needed so that total water minus retained water lands near that target. That makes retention a structural part of the calculation rather than an afterthought.

Estimated strength is handled separately from the pour schedule. You choose an extraction target, the tool divides that value by the water-to-coffee ratio, and the resulting total dissolved solids estimate is compared with the preset's expected range. That is why two brews can share the same beverage size but land in different strength bands when ratio or extraction target changes.

The schedule itself is deterministic. Bloom water is taken as a share of total water, the remaining water is split across the selected number of pours, and each pour inherits a time slice from the total brew time after bloom. All calculations stay in the browser and no network call is made while you use the tool.

Formula Core

The core math answers a practical question: how much coffee and water are required to yield the drink size you want after the grounds keep some liquid back?

mcoffee = Vtarget R-A mwater = mcoffee×R Vyield = mwater-mcoffee×A TDS = E R
Coffee brew planner symbols
Symbol Meaning in this tool Unit Where it comes from
Vtarget Requested beverage size mL Brew size
R Water per gram of coffee g/g Water to coffee ratio
A Retained water per gram of coffee g/g Coffee retention
E Chosen extraction target % Extraction target
TDS Estimated strength of the brewed liquid % Computed in Brew Snapshot

With a 360 mL pour-over at ratio 15.5 and retention 2.2, the planner computes about 27.1 g of coffee and 419.6 g of total water. At an extraction target of 20%, estimated TDS is about 1.29%.

Method Defaults and Schedule Logic

Each preset loads a full starting profile, not just a ratio. The shipped set includes pour-over, Chemex, espresso, French press, AeroPress, cold brew concentrate, and moka pot, each with its own yield, brew time, bloom settings, retention assumption, and expected strength band.

Coffee brew planner presets
Method Default yield Ratio Brew time Expected TDS band
Pour-over 360 mL 15.5:1 210 sec 1.25% to 1.45%
Chemex 600 mL 16:1 270 sec 1.25% to 1.40%
Espresso 36 mL 2:1 28 sec 8.00% to 12.00%
French press 480 mL 15:1 240 sec 1.20% to 1.50%
AeroPress 230 mL 13:1 120 sec 1.30% to 1.60%
Cold brew concentrate 1000 mL 5:1 43200 sec 3.00% to 5.00%
Moka pot 180 mL 7:1 320 sec 3.00% to 5.00%

After the preset is chosen, the schedule is built in three passes: reserve bloom water, split the remaining water across the selected pours, then spread those pours across the available post-bloom time. That is why increasing Pour steps changes both the table rows and the line in Pour Timeline.

The most important boundary is ratio versus retention. If the ratio is less than or equal to retained water per gram of coffee, the planner cannot produce a liquid yield, so it shows the warning about increasing ratio or reducing retention and suppresses the schedule and charts. A softer boundary appears when final yield drifts more than 5% from the requested beverage size; in that case the recipe still renders, but the warning reminds you that the served cup will not match the target closely.

Coffee brew planner controls and effects
Input or output surface What changes when you move it
Brew size Scales coffee dose and total water upward or downward.
Water to coffee ratio Changes dose math, expected yield behavior, and the strength point on Brew Control Map.
Extraction target Changes estimated TDS and the strength label, but not the water schedule.
Bloom share, Bloom duration, Pour steps, and Coffee retention Reshape the timed recipe, final yield, and warning behavior.

Step-by-Step Guide:

The fastest way to get a trustworthy plan is to set a realistic brew target first, then let the schedule explain how to get there.

  1. Choose a Method that matches your brewer. The preset immediately loads a ratio, brew time, retention value, and expected strength band that fit that style.
  2. Enter the desired Brew size and review Brew Snapshot. At this stage you should see coffee dose, total water, ratio, grind label, and a first strength badge.
  3. Adjust Water to coffee ratio, Brew time, Pour steps, Water temperature, and Extraction target only if you have a clear reason. The TDS badge and extraction line respond immediately.
  4. Open Advanced for Bloom share, Bloom duration, and Coffee retention. If the summary disappears or the warning says to increase ratio or reduce retention, fix that first before looking at the charts.
  5. Read the Recipe Breakdown table from top to bottom. Each row tells you when a pour starts, when it ends, how much water to add, and how much cumulative water should be in the brewer by that point.
  6. Check Pour Timeline, Brew Control Map, and Recipe JSON before brewing. If the map lands outside the preset band or the yield warning stays visible, revise the plan before you grind coffee.

A good finished plan gives you a believable dose, a schedule you can follow by timer and scale, and a strength estimate that suits the cup you want.

Interpreting Results:

The most important outputs are the coffee dose, total water, expected final yield, and estimated TDS. The schedule tells you how to execute the plan, but the summary tells you whether the plan is internally coherent.

  • If Yield in the summary sits close to your requested beverage size and there are no warnings, the ratio and retention assumptions are internally consistent.
  • If the TDS badge flips to light-bodied or heavy-bodied, the planner is saying your chosen ratio and extraction target sit outside the preset's expected strength band.
  • If Brew Control Map labels the point diluted or concentrated, read that as a comparison against the preset ratio, not as a universal judgment about quality.
  • If a warning says the beverage yield will differ because of retention, plan to weigh the brewed liquid after the run and decide whether the retention assumption was too high or too low.

The false-confidence trap here is treating estimated TDS as a measured number. It is an estimate derived from your chosen extraction target and ratio, not a refractometer reading from the actual cup. The best verification step is to brew once, compare the real drawdown and served volume with Recipe Breakdown and Yield, then decide what to adjust for the next round.

Worked Examples:

Filter baseline for a repeatable morning brew

Use the pour-over preset with a 360 mL target, ratio 15.5, brew time 210 seconds, bloom share 16%, bloom duration 45 seconds, and retention 2.2 g/g. The planner produces about 27.1 g coffee, 419.6 g total water, 67.1 g bloom water, and an estimated TDS of 1.29%.

In Recipe Breakdown you get one bloom row plus three pours, and Brew Control Map places the brew close to the preset target zone. That is the kind of plan you can brew once and then keep as a stable house recipe.

A deliberately lighter cup

Keep the same pour-over method but push the ratio to 17:1 and lower Extraction target to 18% for a 350 mL brew. The planner drops the dose to about 23.6 g, raises total water to about 402.0 g, and estimates TDS near 1.06%.

Now the summary badge turns light-bodied, and Brew Control Map shifts into the diluted and weak region. That tells you the plan is intentionally outside the default pour-over strength window.

Why the planner sometimes refuses to build a recipe

Set ratio to 2.0 while leaving Coffee retention at 2.2 g/g. The planner can no longer make total water exceed retained water, so Brew Snapshot clears and the warning says to increase ratio or reduce retention so the brew yields liquid coffee.

The corrective path is straightforward: raise ratio above retention or lower retention to a realistic figure for the brew style. Once that inequality is fixed, Recipe Breakdown, Pour Timeline, and Brew Control Map return automatically.

FAQ:

Does the planner measure extraction from the brewed cup?

No. It estimates TDS from your chosen extraction target and ratio. The calculation is useful for planning, but it is not a direct reading from brewed liquid.

Why does the requested beverage size not always match the yield warning?

Because the tool subtracts retained water from total brew water. If retention is high relative to the ratio, expected final yield can drift away from the size you asked for.

Can I use this for espresso and cold brew too?

Yes. The preset list includes espresso, cold brew concentrate, moka pot, French press, AeroPress, Chemex, and pour-over. Each preset changes the default yield, ratio, brew time, retention, and strength band.

Is my brew data sent anywhere?

No. This package runs locally in the browser and the tool files do not include a server request path for your recipe inputs.

Glossary:

Bloom
The opening wetting phase that uses a share of total water before the main pours.
Extraction target
The assumed percentage of soluble material removed from the coffee.
Retention
Water the grounds keep back, expressed per gram of coffee.
TDS
Estimated total dissolved solids, used here as a strength cue.

References: