Reference¶
Look-up numbers for dialling in: brewing standards, filter and espresso targets, water specifications, per-method starting parameters, extraction formulas, burr facts, and a glossary. See also: hub, Explanation, How-to guides.
Brewing Standards¶
Published targets for brewed coffee strength and extraction. The SCA row is the one most specialty guides quote.
| Standard | TDS (strength) | Extraction yield | Brew ratio | Water temperature | Source |
|---|---|---|---|---|---|
| SCA Golden Cup (filter) | 1.15–1.35% (11.5–13.5 g/L) | 18–22% | 55 g/L ± 10% (≈ 1:18) | 93 °C ± 3 °C (200 °F ± 5 °F) at contact | Moccamaster / SCA |
| European preference (SCAE era) | 1.20–1.45% | — | — | — | Wikipedia: Coffee extraction gives this as the European ideal strength (checked 2026-09-28 via search listing) |
| ECBC certification (founded by the Norwegian Coffee Association) | 1.30–1.55% | — | — | — | Moccamaster USA: What does it take to get ECBC certification? (checked 2026-09-28 via search listing). Wikipedia gives Norway's standard as 1.40 ± 0.10% |
| SCA / UC Davis chart (2023) | Map, not a box: sensory attributes and two consumer-liking clusters plotted over TDS × EY × brew ratio | — | — | — | Guinard et al. 2023 |
A dash (—) means the cited source gives no figure for that column.
Contact time
Summaries of the Golden Cup standard quote a total contact time of about 4–8 minutes for automatic drip brewers, which is also the window used in SCA brewer certification. Manual pour-over usually finishes in 2:30–4:00 because it uses a finer grind.
Filter Coffee Targets¶
Roaster baseline from the NiR Coffee brew guide, compared with the SCA figures above.
| Parameter | NiR baseline | Note |
|---|---|---|
| Ratio | 15 g coffee to 250 g water (≈ 1:16.7) | Stronger than the SCA 55 g/L (≈ 1:18) |
| Temperature | 90–93 °C | Hotter for washed coffees, cooler for experimental or "funky" processed coffees |
| Pour schedule | 45 g bloom for 45 s, then 4 pours of about 51 g, pouring done around 2:00 | Drawdown follows; batch brewers run longer |
| Pours | Bloom + 4; the 5-pour high-extraction recipe is an alternative for ultra-light imports | See How-to Guides |
| TDS target | 1.20% to 1.45% | Matches the European preference band, above the SCA 1.15–1.35% band |
| Extraction yield | 18% to 22% | See the note below |
Beyond 22% EY
The 18–22% band comes from the classic control chart (see Explanation). Extractions above 22% are often described as astringent, but low-fines grinders and very light roasts can exceed 22% and still taste clean. Treat 22% as a warning sign, not a hard limit.
Espresso Targets¶
| Parameter | Modern specialty baseline (NiR) | Italian standard (INEI) |
|---|---|---|
| Dose | 20 g (double basket) | 7 g ± 0.5 g (single) |
| Ratio / yield | 1:2 (for example 20 g in, 40 g out) | 25 ml ± 2.5 ml in cup, including crema |
| Time | 25–35 s including pre-infusion | 25 s ± 2.5 s |
| Water temperature | ~93 °C | 88 °C ± 2 °C at the group, 67 °C ± 3 °C in the cup |
| Pressure | ~9 bar; ~6 bar for light-roast or "turbo" shots | 9 bar ± 1 bar |
| Beverage TDS | roughly 8–12% (typical refractometer readings) | — |
Sources: NiR Coffee Brew Guide, Istituto Espresso Italiano.
Brew Method Parameters¶
Typical starting points collected from guides and community practice. These are not standards. Adjust grind first, then ratio.
| Method | Grind | Ratio (coffee : water) | Water temp | Total time |
|---|---|---|---|---|
| Espresso (traditional) | Fine | 1:1.5 – 1:2.5 | 90–96 °C | 25–35 s |
| Espresso ("turbo", low pressure) | Fine, coarser than traditional | ~1:3 | 90–96 °C | ~10–20 s at ~6 bar |
| Moka pot | Fine-medium | Set by filling the basket level | Start with hot water in the base | Stop at the first gurgle |
| AeroPress | Fine to medium | 1:11 – 1:17 | 80–100 °C | 1–3 min |
| Pour-over (V60, Kalita, Origami) | Medium-fine | 1:15 – 1:17 | 90–100 °C (hotter for light roasts) | 2:30–3:30 |
| Chemex | Medium-coarse (thick filter) | 1:15 – 1:17 | 92–96 °C | 4–5 min |
| Batch / auto-drip (SCA-certified) | Medium | 55 g/L (≈ 1:18) | 92–96 °C | 4–8 min contact |
| French press / immersion | Coarse | 1:15 – 1:17 | 93–100 °C | 4 min steep plus settling |
| Flash chill (Japanese iced) | Medium-fine | Same total ratio as hot; ~30–40% of the water as ice in the server | 90–96 °C | As pour-over |
| Cold brew | Coarse | 1:4 – 1:8 concentrate (dilute to serve), 1:12 – 1:15 ready-to-drink | Room temp or fridge | 12–24 h |
Water Specifications¶
SCA Brewing Water Standard¶
| Characteristic | Target | Acceptable range |
|---|---|---|
| Odour / colour | Clean, fresh, odour-free; clear | — |
| Total dissolved solids (TDS) | 150 mg/L | 75–250 mg/L |
| Calcium hardness (as CaCO3) | 68 mg/L (4 grains) | 17–85 mg/L (1–5 grains) |
| Total alkalinity (as CaCO3) | 40 mg/L | At or near 40 mg/L |
| pH | 7.0 | 6.5–7.5 |
| Sodium | 10 mg/L | At or near 10 mg/L |
| Chlorine | 0 mg/L | 0 mg/L |
Source: SCA News — Dissecting SCAA's Water Quality Standard.
Espresso machine water
Machine makers publish their own water specifications (hardness, alkalinity, chloride, pH) and may void warranties when they are not met. Check the manual for your machine; the SCA table is a flavour standard, not a boiler specification. Chloride (Cl⁻, from salts such as calcium chloride) promotes pitting of stainless steel even when chlorine is 0. For example, La Marzocco specifies 0–30 mg/L chloride and warns that more causes severe pitting corrosion and adds sourness and astringency to espresso (La Marzocco water specifications, PDF, checked 2026-09-28).
Remineralisation Concentrates (1000 ppm as CaCO3)¶
Dissolve in 1 L of distilled or RO water. Each concentrate adds 1 ppm per 1 g added to 1 L of finished water.
| Salt | Formula | Grams per litre for 1000 ppm | Adds |
|---|---|---|---|
| Epsom salt | MgSO4·7H2O | 2.46 g | GH (magnesium) |
| Baking soda | NaHCO3 | 1.68 g | KH (alkalinity), ~0.46 mg/L sodium per ppm KH |
| Potassium bicarbonate | KHCO3 | 2.00 g | KH without sodium |
| Calcium chloride dihydrate | CaCl2·2H2O | 1.47 g | GH (calcium), plus chloride |
Figures are calculated from molar masses and match the Barista Hustle water recipe (2.45 g Epsom, 1.68 g baking soda per litre). The SCA-target direct dose for 1 L (GH 68 / KH 40) is 0.167 g Epsom salt plus 0.067 g baking soda.
Hardness Unit Conversions¶
| Unit | Equals (mg/L as CaCO3) |
|---|---|
| 1 mmol/L Ca²⁺ or Mg²⁺ | 100.1 |
| 1 mmol/L HCO3⁻ (alkalinity) | 50.0 |
| 1 grain per US gallon (gpg) | 17.1 |
| 1 °dH (German degree) | 17.8 |
Extraction Formulas¶
| Quantity | Formula | Example |
|---|---|---|
| Brew ratio | water mass ÷ dose | 250 g ÷ 15 g = 1:16.7 |
| Extraction yield (percolation, espresso) | beverage mass × TDS ÷ dose | Espresso: 40 g × 9% ÷ 20 g = 18% |
| Extraction yield (pour-over) | beverage mass × TDS ÷ dose | 220 g × 1.35% ÷ 15 g = 19.8% |
| Beverage mass (paper filter) | brew water − retained water (≈ 2 g water per g coffee, varies with grind and filter) | 250 g − 30 g ≈ 220 g |
| Strength in g/L | TDS % × 10 | 1.35% ≈ 13.5 g/L |
Burr Performance Comparison (80mm Flat)¶
| Metric | SSP Multipurpose (MP) | SSP High Uniformity (HU) | Weber EG-1 DB-2 "Ultra" |
|---|---|---|---|
| Maker | SSP | SSP | SSP, for Weber Workshops |
| Clarity | Very high | Moderate | Very high |
| Body / mouthfeel | Light (tea-like) | Heavy (syrupy) | Light |
| Fines production | Low (v2 adds small finishing flats for espresso) | Moderate, traditional | Minimal ("ultra low fines") |
| Ideal application | Filter, modern light-roast espresso | Traditional espresso, milk drinks, medium-dark roasts | Pour-over only; not suitable for espresso per Weber |
| Espresso flow rate | Fast, needs a fine grind | Traditional, more forgiving | — |
| Forgiveness | Low (demands good puck prep) | High | — |
Sources: Weber Workshops EG-1 burrs, SSP burr guide (Sigma Coffee), MP vs HU for espresso, Espresso Aficionados burr catalog.
Note: burr alignment, temperature stability, and puck preparation heavily change real-world results. The EG-1 also offers a DB-1 "Core" set recommended for both filter and espresso.
Glossary¶
| Term | Meaning |
|---|---|
| TDS | Total dissolved solids: percentage of the beverage mass that is dissolved coffee (measured with a refractometer) |
| EY / PE | Extraction yield / percent extraction: percentage of the dry dose that ended up dissolved in the beverage |
| Brew ratio | Coffee dose to brew water (filter) or dose to beverage yield (espresso) |
| Bloom | First small pour that wets the bed and lets CO2 escape |
| Drawdown | Time for the last water to drain through a percolation bed |
| Channeling | Water finding preferred paths through a bed or puck, over-extracting them and under-extracting the rest |
| Fines / boulders | Very small / very large particles in a grind distribution |
| WDT | Weiss Distribution Technique: stirring grounds with thin needles to break clumps |
| GH / KH | General hardness (Ca²⁺ + Mg²⁺) / carbonate hardness (alkalinity), both usually quoted as ppm CaCO3 |
| Pre-infusion | Low-pressure wetting of the espresso puck before full pressure |
| Turbo shot | Coarser, lower-pressure (~6 bar), fast (~10–20 s) espresso at ~1:3 |