Learning to
Brew
A companion to the SCA Brewing Foundation course. Read it before class to prepare, and after class to review. Everything here serves one goal: brew a tasty cup on purpose, and know what to change when it isn't.
Six sections, four practice tools.
Brewing is
controlled dissolving.
Hot water dissolves and extracts the water-soluble material from roasted, ground coffee. That is the entire event. Every technique, gadget, and recipe simply controls how much dissolves, and how evenly.
Coffee is the seed of a fruit, grown in the tropics, harvested, processed, transported, and roasted before it ever meets your kettle. Brewing is the last step, and the only one in your hands.
Water passes between particles, carrying dissolved coffee into the cup. Extraction is how much; evenness is how well.
Seven elements decide
every brew.
Ratio is just division
A ratio of 1:16 means one gram of coffee for every sixteen grams of water. Divide your brew water by the ratio number and you have your dose. Converting a ratio to a per-liter recipe must respect water density: one liter at 93 °C weighs 963 g, which is why 1:17.5 works out to about 55 g per liter.
Brew ratio calculator
Enter your brew water and slide the ratio. The dose is calculated for you, with the per-liter equivalent the SCA guideline is written in.
Inside the SCA balanced zone (1:15 to 1:20, about 50 to 65 g per liter).
Six ways to
brew a coffee.
Left to right: ibrik (boiling), pour-over (gravity filter), moka pot (percolation and pressure), espresso (pressure), French press (immersion), syphon (vacuum).
Explore a method
The six principles a brewing device can work on. Tap one to see how it moves water through coffee, the devices that use it, and where it lands against the SCA Ideal.
Syphon, French press, gravity drippers
Moderate ratios and full control of time and temperature. These are the devices the Brewing Control Chart was drawn for.
Moka pot, ibrik, espresso
They brew intentionally far stronger than the Ideal range. A different target, not worse coffee.
Numbers worth
knowing.
Grind: the double lever
A finer grind exposes more surface area, so water extracts more, faster. In gravity and pressure brewing it also slows the flow, which stretches contact time. One adjustment, two effects, both pushing extraction the same way. If a brew tastes sour and thin, grind finer. If it tastes bitter and drying, grind coarser.
Pressure methods need a fine grind to create resistance. Immersion methods like a coarse grind because the steep is long. On a dripper, the grind is close to right when the outflow turns from a stream to a drip inside the recommended brew time.
| BREW METHOD | TIME | COFFEE : WATER | GRIND SIZE · µM |
|---|---|---|---|
| Pour over | 3:40 | 1 : 16 | 400 to 800 |
| French press | 10:00 | 1 : 13 | 600 to 1000 |
| AeroPress | 2:20 | 1 : 15 | 500 to 900 |
| Moka pot | 1:30 | 1 : 11 | 350 to 700 |
| Drip brewer | varies | 1 : 17 | 400 to 900 |
| Espresso | 0:26 | 1 : 2 | 250 to 500 |
| Cold brew | 16 h | 1 : 10 | 600 to 1100 |
| Syphon | 1:40 | 1 : 15 | 400 to 800 |
Typical time, ratio, and grind-size window by method, in microns (200 to 1200 µm scale, after the Kruve sieve chart). Finer for pressure, coarser for immersion.
The bloom: wetting the bed releases trapped CO₂ so water can reach the coffee evenly.
Turbulence and the bloom
Turbulence is the mixing movement of water through the grounds, created by pouring, stirring, or boiling. The right amount separates particles and keeps fines from clogging the bed, producing a more even extraction.
Fresh coffee holds carbon dioxide from roasting. Wetting the bed first and pausing briefly lets that gas escape as the bloom, preventing channels and dry pockets before the main pour.
Filters shape the body
Paper gives the cleanest, lightest cup and is single-use; store filters dry, airtight, and away from light, and pre-wet before brewing to heat the device and rinse paper flavors. Cloth gives more body and needs meticulous care. Metal passes fine particles and oils for the heaviest, cloudiest cup.
Paper, metal, and cloth each leave a different cup behind.
The pour-over,
step by step.
A flat, even coffee bed after drawdown is the signature of an even extraction.
Steep, then separate
Heat the device, add coffee, start the timer, wet all the grounds, lid on, then press slowly and decant immediately.
Set, activate, time
Set the bed, fill the tank, activate, and time from first wetting to last drip. Then evaluate like any other brew.
Clean gear, better coffee
Brewing devices, servers, grinders, and reusable filters must be cleaned to prevent taints in the cup. Clean equipment also runs consistently, faults less, and lasts longer. Manual drippers get cleaned between brews; the auto brewer's spray head stays clear so water flows evenly. Watch the water side too: corrosion and limescale are the two classic equipment killers. No brewer is self-cleaning.
Extraction, strength,
and balance.
Describe every brew by its color, aroma, taste, and body. Then let two numbers explain what you tasted: extraction is the share of the grounds that dissolved, and strength is how concentrated the cup is.
The Brewing Control Chart
The chart plots strength against extraction. Diagonal lines are coffee-to-water ratios: your ratio fixes which line you are on, and grind, time, and temperature slide you along it. The target box sits at 18 to 22% extraction and 1.15 to 1.45% strength.
Reading flavors onto the chart: low extraction tastes sour and thin, high extraction tastes bitter and drying, low strength tastes watery, high strength buries complexity. Sour and weak? Finer or longer. Bitter and harsh? Coarser or shorter.
Extraction is the flavor profile. Strength is the volume knob. TWO NUMBERS, ONE CUP
Where is your brew?
Enter the dose, the beverage weight, and the TDS reading from a refractometer. Extraction is calculated and the brew is plotted on the chart.
Inside the ideal window.
The SCA Brewing Control Chart, simplified: strength up the side, extraction along the bottom, the ideal box where both are optimum. Your brew is the dot.
The brewing vocabulary,
defined.
The percentage of the ground coffee's mass that dissolved into the beverage. 20 g of grounds giving up 4 g is a 20% extraction. The SCA optimum is 18 to 22%.
The concentration of dissolved solids in the cup, measured as TDS with a refractometer. The SCA optimum for gravity and immersion brews is 1.15 to 1.45%.
A brew with optimum flavor and pleasant strength: optimum extraction and optimum concentration achieved together.
The mass of dry coffee against the mass of brew water. 1:20 to 1:15 is the balanced zone; about 50 to 65 g per liter.
The burst of CO₂ released when hot water first wets fresh grounds. Wetting the bed and pausing lets gas escape for a more even extraction.
The mixing movement of water through the grounds, created by pouring, stirring, or boiling. The right amount evens out extraction.
A map of strength against extraction with diagonal ratio lines and a target box at 18 to 22% extraction and 1.15 to 1.45% strength.
Paper, cloth, or metal. Paper brews cleanest and lightest, cloth adds body, metal passes fines and oils for the heaviest cup.
Keeping brewed coffee hot: a closed, insulated container at 80 to 85 °C. Hot plates evaporate water and wreck aromatics.
Knowledge check.
Ten questions in the spirit of the written exam. Tap an answer to see feedback; your score tallies at the end.
Test yourself
Multiple choice, single correct answer, like the SCA written exam.