Filter coffee at home: a practical guide to ratio, grind and water temperature

Making filter coffee at home is not hard, but three settings must be right: ratio, grind size and water temperature. Each noticeably changes the taste of the cup. Here is the order we teach our baristas at the roastery.

1. Ratio: 1 gram of coffee to 16 grams of water

The starting point is 1:16. A 300 ml cup needs about 18–19 grams of coffee. A coffee scale is far more consistent than a spoon, but if you do not have one you can count a tablespoon as about 6 grams. Our brew calculator does the conversion for you.

2. Grind: the size of a grain of sand

The ideal grind for filter is between sea salt and table salt. If the coffee tastes bitter and astringent the grind is too fine; if sour and watery, too coarse. Change only the grind setting by one step each time, and do not move three things at once.

3. Water temperature: 92–96 °C

Let boiled water sit for a minute. Light roasts like hotter water (95–96 °C), dark roasts cooler water (90–92 °C). Water quality matters too: hard tap water mutes the coffee's acidity, while distilled water flattens the taste. Soft bottled water is a good middle path.

4. The brewing flow

1. Wet the filter and warm the dripper.
2. Add the coffee and level it; pour twice the weight of coffee in water (the bloom) and wait 30 seconds.
3. Pour the remaining water in 2–3 pours, in circles from the centre outwards.
4. Total time should be 2:30–3:30 minutes.

5. Troubleshooting

• Too bitter: grind coarser or drop the water by 2 °C.
• Too sour: grind finer or extend the time.
• Watery: move the ratio to 1:15.

Which beans to start with?

For first attempts we suggest a balanced and forgiving coffee: Colombia Huila or the Morning Blend. Delicate origins such as Ethiopia are a joy once your settings are dialled in.

Logging every brew in a notebook is the quickest way to mastery: date, coffee, grams, water, time and tasting note. After three weeks you will have your own recipes; by joining one of our cupping sessions you can share them with us too.

In the first week change just one variable and write it down: either grind, ratio or water temperature. Faulty cups are valuable data too; they help you find which setting is the real problem. When you get stuck, do not hesitate to ask the baristas in our cafés.

Remember: good coffee comes from consistency more than expensive equipment. Try three times with the same scale, the same time and the same water; that is how you will feel the difference.