Filter coffee

A starting recipe, and the range around it

Sourced

The Specialty Coffee Association's brewing standard centres on about 55 grams of coffee per litre of water. Most home recipes sit at or slightly stronger than that.

The ratio is the published SCA guideline; the other ranges describe common practice. All of them are starting points to adjust by taste, and different brewers have different sweet spots.

What the paper does to the cup

CoffeeHQ explanation

A paper filter traps almost all of the coffee's oils and the finest particles. Without them the drink has a lighter body and a cleaner finish, and individual flavours are easier to pick out. This is the main reason filter coffee tastes so different from French press coffee made from the same beans.

Metal and cloth filters let more through. A metal filter gives a heavier, slightly cloudy cup; cloth sits between the two. None of these is better. They are a choice between clarity and body.

The main ways to brew it

Tendency, not a guarantee

Pour-over by hand

Water poured from a kettle over a cone or flat-bottomed dripper. It gives the most control and asks the most attention; small changes in pouring show in the cup.

Automatic drip machine

The machine heats and distributes the water. Results depend on whether it reaches a proper brewing temperature and wets the coffee evenly, which varies widely between models.

Batch brewer

A larger machine brewing a litre or more at a time, common in cafés. Done well it is very consistent, because the same recipe runs identically every time.

Thick-paper brewers

Brewers such as the Chemex use a much heavier paper that holds back even more oil, for an especially clean and light-bodied cup.

If it tastes wrong

Tendency, not a guarantee

First decide whether the problem is strength or flavour. Weak and strong are fixed with the ratio; sour and bitter are fixed with the grind.

Weak and watery, but otherwise pleasant

Usually because: Not enough coffee for the amount of water.

Change first: Use more coffee, keeping the grind the same.

Work through weak coffee

Sour, sharp or hollow

Usually because: Under-extraction is the usual reading: the water ran through too quickly to dissolve enough of the coffee to balance its acidity.

Change first: Grind a little finer, keeping the amount of coffee the same.

Work through sour coffee

Bitter, harsh or drying

Usually because: Over-extraction, often from a grind so fine that the water stalls in the bed.

Change first: Grind a little coarser. If the brew took much longer than usual, this is the cause.

Work through bitter coffee

Dull and flat whatever you change

Usually because: Stale coffee, or water that is very hard or very soft. Neither can be corrected with technique.

Change first: Check the roast date first, then try the same recipe with a different water.

Check your water

Two comparisons worth running

CoffeeHQ explanation

• Strength versus extraction

  Change

  Brew twice. In the second, use about a fifth more coffee and change nothing else.

  Keep the same

  The grind, the water, the temperature and the way you pour.

  What to notice

  The second cup should be stronger but similar in character. That is what changing the ratio does, and it is different from what changing the grind does.

• One step finer

  Change

  Brew twice, the second one notch finer on the grinder.

  Keep the same

  The amount of coffee and water, and everything else.

  What to notice

  The second brew should run slower and taste fuller, and may begin to turn bitter. This is how you find the edge of a coffee's sweet spot.

Against other black coffees

Tendency, not a guarantee

• Americano — Similar strength, but made by diluting espresso. Heavier in body and usually more roasted in flavour.
• French press — Steeped rather than poured through, and filtered through metal. Fuller and heavier, with some sediment.
• V60 pour-over — One specific way of making filter coffee by hand, with its own recipe and technique.

What to do next

• Coffee-to-water ratio calculator — works out how much coffee your cup or jug needs at the strength you prefer.
• Dial in filter coffee — a step-by-step way to adjust grind and ratio for a new bag, one change at a time.
• Extraction basics — explains why sour and bitter are opposite ends of one scale, which makes the fixes above make sense.
• Paper vs. metal filters — the filter changes the cup more than most equipment does.
• Become a barista — A structured programme from dose and grind through milk, drinks and maintenance.