Coffee Brewing Basics: Grind, Ratio & Method

Brewing coffee is extraction: water dissolves flavour from ground beans, and how much it dissolves depends on how finely the coffee is ground, how much coffee meets how much water, how hot that water is and how long they stay in contact. Every brew method is simply a different way of balancing those variables. Once you understand them, you can make any brewer taste better — and work out why a cup went wrong.

Grind size: the variable that matters most

Finer grounds expose more surface area, so water extracts flavour faster. They also slow water down, which lengthens the brew. Coarser grounds extract more slowly and let water pass more quickly. That is why each method has its own grind range: a short, pressurised brew needs finer coffee; a long steep needs coarser coffee.

• Moka pot: fine, but coarser than espresso — roughly the texture of table salt.
• Pour-over / filter: medium to medium-fine, similar to coarse sand. Adjust by how fast the water drains.
• French press: coarse, like rough breadcrumbs, so the grounds steep evenly and stay behind the mesh.

Consistency matters as much as size. Blade grinders chop unevenly, leaving dust that over-extracts beside chunks that under-extract, so the cup can taste bitter and sour at once. A burr grinder crushes beans to a more even size, which makes every other adjustment easier to judge. Grinding just before brewing also keeps more aroma in the cup.

Coffee-to-water ratio: a starting point, not a rule

Ratio controls strength. For pour-over and French press, a common starting range is about 1 g of coffee to 15–17 g (or ml) of water — for example, 15 g of coffee to roughly 250 ml of water. Treat this as a place to begin, not a correct answer: beans, roast and personal taste all move it. A moka pot works differently because the basket and water chamber set the dose; fill the basket level and the water to just below the valve.

Weighing coffee and water with a scale is the simplest way to make a good cup repeatable. Scoops vary with roast and grind, so a cup you liked yesterday is hard to recreate from volume alone. Once you have a reliable dose, change ratio in small steps and note what you did.

Water, temperature and time

• Water makes up most of the cup. If your tap water tastes of chlorine or leaves heavy scale in the kettle — common in some South African municipalities — filtered water often gives a cleaner result and less build-up in brewers.
• Temperature: just-off-the-boil water is a practical starting point for pour-over and French press. Leaving a boiled kettle to settle briefly is usually enough; you do not need an exact number to brew well.
• Time works with grind. A pour-over typically finishes in a few minutes and a French press is commonly steeped for around four minutes before pressing. Use these as reference points, and let taste decide whether to go longer or shorter.

How the three common methods differ

A moka pot pushes water up through the coffee using steam pressure from the base, producing a short, strong, heavy-bodied brew. It is quick and suits people who like intense coffee or milk drinks. Heat and grind are the main controls; the step-by-step method and care are covered in our moka pot guide, so they are not repeated here.

Pour-over lets water flow through a bed of coffee and a paper filter. The filter holds back oils and fine particles, giving a lighter, cleaner cup where the character of the beans comes through clearly. It rewards attention: grind, pouring speed and ratio all show up in the taste.

A French press steeps coffee fully in water, then separates it with a metal mesh. Oils and some fine particles pass through, so the cup is fuller and richer, with a little sediment at the bottom. It is forgiving and easy to scale for several people. None of these methods is better overall — they produce different styles of coffee.

Adjust one thing at a time

When a cup is not right, change a single variable and brew again. Grind is usually the first lever for flavour balance; ratio is the lever for strength. If you change grind and dose together, you will not know which one helped.

Troubleshooting your cup

• Bitter, harsh or drying: likely over-extracted. Grind a little coarser, shorten the brew, or on a moka pot lower the heat and take it off as the flow turns pale.
• Sour, thin or sharp: likely under-extracted. Grind a little finer or extend the brew time; check the water was hot enough.
• Weak but otherwise balanced: use more coffee for the same water. Strength is a ratio question, not a grind question.
• Too strong but balanced: add a little more water, or dilute after brewing.
• Muddy or slow to drain (pour-over): the grind is probably too fine or very uneven. Go coarser, and check your grinder for dust.
• Water rushes through and the cup tastes flat: the grind is too coarse. Go finer in small steps.
• Gritty French press: grind coarser, press slowly, and leave the last centimetre in the jug rather than pouring the sediment.

Keeping coffee fresh

Coffee loses aroma after roasting, and faster once ground. Buy amounts you will use within a few weeks, keep beans in an airtight, opaque container away from heat, light and humidity, and grind only what you need for each brew. Avoid storing an open bag next to the stove or kettle, where warmth and steam speed up staling.