Coffee ratio calculator

The Golden Ratio and why it works

The Specialty Coffee Association (SCA) standard is 1:16 to 1:18 by weight — one gram of coffee to 16-18 grams of water. For a typical 12oz cup (355ml water), that's 20-22g of coffee. Most home cooks brew at 1:10 to 1:13 and wonder why their coffee tastes bitter and over-extracted — they're using too much coffee for their pour-over, or grinding too fine.

Brewing method changes the ideal ratio because contact time and filtration differ:

• Pour-over (V60, Chemex): 1:16 to 1:17. 20-25g coffee per 12oz cup.
• Drip machine (Mr. Coffee, Breville): 1:15 to 1:18. 22-25g per 12oz cup.
• French press: 1:12 to 1:15. Coarser grind, longer extraction. 28-35g per 12oz.
• AeroPress: 1:14 to 1:16. 17-20g per 8oz cup.
• Espresso: 1:2 (ristretto) to 1:3 (lungo). 18g coffee in, 36-54g liquid out.
• Cold brew concentrate: 1:4 to 1:5. Diluted 1:1 or 1:2 with water/milk to serve.
• Moka pot: Fill filter basket to brim, no tamping. Typically 1:7 to 1:10.

Why weight beats volume

A scoop of coffee varies 20-40% by density based on bean origin, roast level, and grind. Dark roast coffee is less dense than light roast (loses mass during roasting). A fresh light roast scoop could be 15g; a stale dark roast scoop could be 9g from the same scoop size. Scales end this variance. A $15 Hario V60 scale is the starting point. A $49 Timemore Black Mirror adds 0.1g precision and a built-in timer for pour-over pacing.

Grind size by method

Match grind to contact time. Longer contact = coarser grind.

• Turkish (lowest): powder, 20-40 micron
• Espresso: fine sand, 200-400 micron
• Moka pot: slightly coarser than espresso
• AeroPress: medium-fine
• Drip machine: medium, like sand
• Pour-over V60: medium-fine to medium
• Chemex: medium-coarse (thicker filter needs coarser grind)
• French press: coarse, like breadcrumbs
• Cold brew: very coarse, like small gravel

A burr grinder is the second-most-impactful coffee upgrade after a scale. Baratza Encore ($170) is the standard home burr grinder. Blade grinders produce inconsistent grind size and are a major cause of bitter+sour coffee simultaneously.

Water temperature is non-negotiable

200°F (93°C), plus or minus 5°F. Too hot burns and over-extracts (bitter, harsh). Too cool under-extracts (sour, thin). Kettles with temperature control (Fellow Stagg EKG, $149) are worth the money. Workaround: boil water, let sit 30 seconds off heat — water drops to ~200°F by then.

Water quality matters more than you think

Coffee is 98.5% water. Hard water (high mineral content) produces dull, heavy coffee. Softened water (sodium-treated) produces flat, sharp coffee. Ideal: moderate mineral content, neutral pH. SCA-spec water is 150 ppm TDS with balanced calcium/magnesium. Practical move: use filtered tap water, not distilled, not softened. Third Wave Water sachets ($20 for 12 gallons of brew water) are popular among obsessives.

The pour-over technique

1. Rinse filter with hot water. Removes paper taste, preheats dripper.
2. Add ground coffee, tare scale to 0.
3. Bloom: pour 2x coffee weight in water (40g water for 20g coffee), wait 30-45 seconds. CO2 escapes.
4. Main pour: slow, steady circles, pouring 40-60g per 10 seconds.
5. Target total time: 3-4 minutes from bloom to final drip.
6. Adjust next brew: too fast (under 3 min)? Grind finer. Too slow (over 4:30)? Grind coarser.

Espresso math

Modern specialty espresso is a 1:2 ratio: 18g coffee produces 36g liquid in 25-30 seconds. Variables:

• Dose (input): 18g for a standard double shot
• Yield (output): 36g (1:2), 27g (1:1.5 ristretto), 54g (1:3 lungo)
• Extraction time: 25-30s
• Temperature: 200-205°F
• Pressure: 9 bar

Adjust grind finer if shots pull too fast (under 20s) — yields sour, watery shots. Adjust coarser if shots pull too slow (over 35s) — yields bitter, harsh shots.

Cold brew at home

Simple recipe: 100g coarsely ground coffee + 500g water, steep 14-18 hours at room temp. Strain through fine mesh + paper filter. Produces ~400g concentrate. Dilute 1:1 with water or milk to serve — so 50g concentrate + 50g milk = one iced coffee.

Cold brew is 65-70% less acidic than hot brew. Great for sensitive stomachs. Does not develop the same aromatic complexity as hot brew — coffee heads are divided. Use a coarse grind and avoid ultralight roasts (designed for pour-over); medium-dark roasts cold brew best.

Milk ratios for lattes and cappuccinos

• Cortado: 1:1 espresso to milk (2oz each)
• Cappuccino: 1:1:1 espresso : steamed milk : foam (2oz each, ~6oz total)
• Flat white: 1:2 espresso to steamed milk, minimal foam (6oz total)
• Latte: 1:3 to 1:4 espresso to milk (8-12oz total)
• Americano: 1:4 espresso to hot water (8-10oz total)

Storage: your coffee is going stale faster than you think

Whole beans stay fresh 2-4 weeks after roast (check roast date on bag — "best by" is often 12 months, which is marketing, not science). Ground coffee stales in 2-5 days. Always buy whole bean, grind immediately before brewing. Store beans in airtight opaque container at room temperature. Not the fridge (condensation). Not the freezer unless you're buying multi-month supply and thawing once (freezer-thaw cycles damage beans).

Related: tea steeping ratio, ml to cups, cups to grams, cocktail ratio.

The upgrade path that transforms coffee

In order: (1) buy a scale, $15. (2) Buy fresh whole beans from a local roaster, $20/lb. (3) Buy a burr grinder, $170 (Baratza Encore). (4) Buy a temperature-controlled kettle, $149 (Fellow Stagg EKG). (5) Pour-over setup (Hario V60, $25 + filters). Total: $400 for specialty-cafe-quality coffee at home, saving $5/day vs. buying coffee out = $1,825/year. Pays back in three months.

Worked example: dialing in a V60 pour-over

Start with 20g medium-fine ground coffee + 320g water (1:16), total brew time target 3:00-3:30.

First brew tastes sour and watery: under-extracted. Grind finer and/or extend brew time. Target: 3:30. If shots still weak, increase coffee to 22g.

Second brew tastes bitter and drying: over-extracted. Grind coarser and/or shorten brew time to 2:45. If still bitter, decrease coffee to 18g.

Third brew: if finer grind crashes time to 4:00+ and bitter, you've gone too far. Back off one notch. Adjustments are iterative; dialing in a new bean takes 3-5 brews.

Worked example: espresso pull adjustment

Target: 18g in, 36g out (1:2 ratio), 25-30 second pull, 200°F water, 9 bar pressure.

Pull 1: 18g in, 36g out in 15 seconds. Too fast = under-extracted (sour). Grind finer.

Pull 2: 18g in, 36g out in 45 seconds. Too slow = over-extracted (bitter). Grind coarser.

Pull 3: 18g in, 36g out in 28 seconds. Perfect. Locked in. Pull again to confirm consistency; variance of ±2 seconds is normal.

Flavor adjustments: too intense → increase ratio to 1:2.5 (18g in, 45g out). Too weak → reduce to 1:1.5 (18g in, 27g out, ristretto). Each shift changes concentration and flavor compound balance.

Worked example: 2-liter cold brew for the week

Ratio: 1:5 coffee to water for concentrate, diluted 1:1 at serving. 400g coarse-ground coffee + 2000g filtered water, steep 18 hrs at room temp in a 3L container.

Strain through cheesecloth, then paper filter. Yield: ~1800g concentrate (some absorbed by grounds). Stored in fridge, lasts 14 days.

To serve: 100g concentrate + 100g cold water/milk + ice = 8oz iced coffee. Concentrate yields 18 servings for ~$4-6 in coffee cost (vs. $90 buying 18 iced coffees at $5 each). Savings: $85+.

Grinder buying guide

• Baratza Encore ESP ($200): 40 grind settings, handles espresso down to pour-over. Starting home burr grinder. Upgraded 2024 from the original Encore.
• 1Zpresso K-Plus manual ($230): hand grinder, best-in-class consistency, 40 clicks per rotation. No electricity needed. Rival to $400+ electric grinders for espresso.
• Baratza Virtuoso+ ($270): built-in timer, better burrs than Encore. Best mid-range home grinder.
• Niche Zero ($700): single-dose espresso grinder, near-zero retention. For serious home espresso.
• Fellow Opus ($225): compact, quiet, 41 grind settings. Good pour-over grinder, marginal for espresso.
• DF64 / DF83 ($350-500): commercial-grade flat burrs, modified home grinder. Great value for espresso heads.

Grind setting affects the ratio. On a Baratza Encore ESP: setting 15 for espresso, 20 for moka pot, 25 for pour-over, 30 for drip machine, 35 for French press, 40 for cold brew. On 1Zpresso K-Plus: 1.4.0 for espresso, 2.0.0 for pour-over, 3.5.0 for French press (each "0" is 10 microns of adjustment).

Bean variety and ratio interaction

• Light roast Ethiopian Yirgacheffe: floral, citrusy, high acidity. Best at 1:16-17 pour-over. More coffee overwhelms the delicate notes.
• Medium roast Colombian: balanced, caramel notes. Versatile — works 1:15-18.
• Dark roast Sumatran: earthy, full body. Can handle 1:13-15 because bitter compounds balance other flavors.
• Espresso blends: typically medium-dark roast, designed for 1:2 extraction. Single-origin espresso is harder to dial — requires grinder precision.
• Decaf: Process affects grind. Swiss Water decaf grinds normally; CO2 decaf often needs slightly finer grind.

Water composition details

SCA-recommended water: 150 ppm total dissolved solids, 17-85 ppm calcium hardness, 40 ppm alkalinity (bicarbonate), pH 6.5-7.5. Most tap water is 2-4x too high in mineral content for ideal coffee.

Practical solutions: Third Wave Water sachets ($20 for 12 gallons of brewing water, mixed with distilled). Brita filter reduces by 20-30%. Buying distilled water ($1/gallon) then adding a pinch of Third Wave gives perfect results. For busy home setup: Brita + tap water tastes distinctly better than straight tap, takes 10 seconds.

Milk steaming temperatures for latte art

• 140-150°F: silky microfoam, pours well for rosettas and hearts
• 150-160°F: comfortable drinking temp, slightly less glossy foam
• 160-170°F: hotter, but microfoam starts to dissipate
• 170°F+: scalding, damages milk proteins, foam collapses quickly

Whole milk foams best (3.5% fat). Oat milk steams beautifully — Oatly Barista or Pacific Foods Barista are reformulated specifically for espresso. Skim milk makes dry, rigid foam. Almond milk is hardest — thin, splits at high temps.

FAQ

Why does my coffee taste different every morning? Variables compound: grind setting drift, water temp variance, bean age, brew time. Lock in one variable at a time. A scale and a thermometer eliminate 70% of day-to-day variance.

Can I use pre-ground coffee? It will be stale within 1-2 weeks of opening. For serious drinking, buy whole bean and grind immediately before brewing.

How long after roast is coffee best? Peak window: 7-21 days after roast. Too fresh (CO2 off-gassing) under-extracts. Too old (oxidation) tastes flat.

Should I store coffee in the freezer? Only if you're storing for 2+ months and will thaw once. Freeze-thaw cycles damage flavor. Airtight opaque container at room temp is ideal.

Why is my espresso bitter even at correct ratio? Water temperature too high (try 198°F instead of 205°F), or grounds too fine, or roast too dark. Try a medium roast bean first.

Is a pod machine worth it? For convenience, yes. For quality, no. Pods cost $0.70 each and produce stale, generic coffee. A $200 grinder + $25 pour-over gear + fresh beans beats any pod machine on quality, at lower per-cup cost after 6 months.

How much caffeine in each brew method per cup? Drip 95-165mg; pour-over 80-200mg; espresso shot 60-80mg; French press 80-135mg; cold brew 150-250mg (longer extraction). Per ounce, espresso is highest; per 8oz cup, cold brew concentrate is highest.

What's the best all-around home setup under $500? Baratza Encore ESP grinder ($200), Hario V60 with scale and kettle ($80), Fellow Stagg EKG temperature kettle ($149), 1-lb local fresh beans ($18). Total $447, makes cafe-quality coffee.