Dial in every shot with numbers, not guesses.
BeanSage is a data-first espresso reference for home baristas. The tables below hold the brew ratios, extraction targets, formulas and corrections needed to place any shot in its correct class.
Espresso ratios, quantified
The brew ratio is the single strongest predictor of strength and flavour balance. It is dose compared against beverage yield, written as 1:n. The tables below hold every number needed to place a shot in its correct class.
| Style | Brew ratio | Yield (18 g dose) | Typical time | Strength (TDS) | Flavour emphasis | Best suited to |
|---|---|---|---|---|---|---|
| Ristretto | 1:1.0 – 1:1.5 | 18 – 27 g | 20 – 25 s | 9 – 12 % | Heavy body, sweet, low acidity | Dark roasts, milk drinks |
| Espresso (normale) | 1:1.5 – 1:2.5 | 27 – 45 g | 25 – 32 s | 8 – 11 % | Balanced acidity, body and sweetness | Default starting point for any bean |
| Lungo | 1:2.5 – 1:4.0 | 45 – 72 g | 30 – 40 s | 6 – 9 % | Thinner body, brighter, more diluted | Light roasts, single origins, sipping |
| Metric | Under-extracted | Target window | Over-extracted | Instrument |
|---|---|---|---|---|
| Dose | < 16 g | 18 – 20 g | > 22 g | Scale, 0.1 g resolution |
| Yield (18 g dose) | < 27 g | 27 – 45 g | > 45 g | Scale, 0.1 g resolution |
| Shot time | < 25 s | 25 – 32 s | > 35 s | Stopwatch |
| Water temperature | < 90 °C | 90 – 96 °C | > 97 °C | Group-head thermometer |
| Pump pressure | < 7 bar | 8 – 10 bar | > 11 bar | Gauge / pressure-profiling device |
| Flow rate | < 0.8 g/s | 1.0 – 1.6 g/s | > 2.0 g/s | Yield ÷ time |
| TDS (strength) | < 7.5 % | 8.5 – 11.5 % | > 13 % | Refractometer |
| Extraction yield | < 18 % | 18 – 22 % | > 23 % | Refractometer + scale |
| Quantity | Formula | Worked example (18 g → 36 g in 27 s) |
|---|---|---|
| Brew ratio | n = yield ÷ dose | 36 ÷ 18 = 1:2.00 |
| Extraction yield | EY % = (yield × TDS) ÷ dose | (36 × 10) ÷ 18 = 20.0 % |
| Flow rate | g/s = yield ÷ time | 36 ÷ 27 = 1.33 g/s |
| Water volume in puck | ≈ dose × 2.0 – 2.5 | 18 × 2.2 ≈ 40 g contact water |
Shot troubleshooting matrix
Each row maps a directly observable defect to its cause and a single correction. Change one variable at a time and log the result before moving to the next.
| Observed symptom | Measured signature | Likely cause | Primary correction | Secondary lever |
|---|---|---|---|---|
| Gushes, pale, watery | < 20 s, flow > 2.0 g/s | Grind far too coarse / dose too low | Grind finer in 2-click steps | Increase dose by 0.5 g |
| Sour, salty, thin | 20 – 25 s, EY < 18 % | Under-extraction | Grind finer until 25 s+ | Raise temperature +1 °C |
| Spraying / early blonding | Uneven flow, blond before 15 s | Channelling, poor puck prep | Level the bed, firm even tamp | WDT distribution tool |
| Drips then stalls | > 40 s, flow < 0.6 g/s | Grind too fine / over-dosed | Grind coarser in 1-click steps | Reduce dose by 0.5 g |
| Bitter, astringent, dry | > 32 s, EY > 23 % | Over-extraction | Grind coarser | Lower temperature −1 °C, shorten ratio |
| Flat, no sweetness | EY 18 – 20 %, TDS < 8 % | Correct extraction, low strength | Lower ratio toward 1:1.8 | Finer grind to raise TDS |
| Heavy, salty finish | TDS > 13 %, time in window | Strength too high | Raise ratio toward 1:2.4 | Prewarm cup, check water |
| Fast first drip, then slows | Drip < 8 s, total > 35 s | Channelling plus fine grind | Re-distribute before tamping | Grind one step coarser |
Continue the dial-in
Reference pages cover equipment methodology and bean-specific variables behind the numbers above.
Brewing lab notes
Long-form tests on grind size, water chemistry, pressure profiling and roasts — each post ends in a logged shot table.
AboutTesting methodology
How shots are measured: scales, refractometers, controlled water recipes and repeat counts behind every figure.
ContactSend your shot log
Stuck on a bean? Submit dose, yield, time and TDS — we answer with a single variable to change.