How to Make Filter Coffee: Ratio, Temperature, Steps
The short answer to how to make filter coffee is this: put freshly ground coffee into a paper or metal filter, brew with 90-96°C (195-205°F) water at a ratio between 1:15 and 1:18, and keep the total brew time between 2.5 and 6 minutes depending on the grind size. When the ratio, grind, and water temperature are right, both an electric drip machine and a manual pour-over dripper (V60, Chemex, Kalita-style cones) give a good cup using the same principle; the steps below apply to both methods.
Getting the Ratio and Grind Size Right
The Specialty Coffee Association's Golden Cup standard recommends 55 grams of coffee per litre of water, which works out to roughly a 1:18 ratio and is a safe starting point for most home brewers. For a stronger cup, move toward 1:15; for a lighter cup, stay closer to 1:17-1:18 — the point is to stay within that range and find your own preference through testing. Grind size depends on the filter type: paper filters have fine pores and need a medium-fine grind, while metal filters have larger pores and need a medium-coarse grind; get it wrong and a too-fine grind in a paper filter slows the flow and turns bitter, while a coarse grind in a metal filter gives a weak, watery cup. Kimor's filter coffee line is sold pre-ground for paper filters and for metal filters, as well as whole bean, precisely to serve these two needs separately; if you have your own grinder, you can buy whole beans and grind to match your brew method.
Water Temperature and Brew Time
Let the water rest for about 30 seconds to a minute after boiling before you start brewing; the SCA's technical standard calls for the water to reach at least 92°C within the first minute of contact with the coffee, stay at or above that temperature for the rest of the brew, and never exceed 96°C. In practice that lands in the 90-96°C range: lower temperatures give a sour, under-extracted cup, while higher temperatures give a bitter, over-extracted one. Total brew time runs about 2.5-4 minutes for manual pour-over drippers and 4-6 minutes for electric drip machines depending on the drip rate; the longer the brew, the more is extracted, so aim for a consistent time with the same ratio and grind.
Why Water Quality Matters
Filter coffee is mostly water by weight, so the water itself shapes the result. The SCA recommends water with 75-150 ppm total dissolved solids (TDS) for brewing coffee; that range keeps very soft (pure/distilled) water from tasting flat and very hard water from tasting mineral-heavy and dull. If your tap water smells or tastes of chlorine, running it through a carbon filter, or simply letting it stand for a few minutes before brewing, is a simple step that can improve the cup. Boiling water repeatedly for long periods drives off dissolved oxygen and flattens the cup, so use fresh water for each brew — it makes a difference even with the same coffee. If you're unsure how hard your tap water is, you can run a side-by-side cup with a lightly mineralized bottled water using the TDS value on the label and decide for yourself which one suits your palate better.
Brewing Filter Coffee Step by Step
First, place the filter (paper or metal) in the brewer; rinse a paper filter with hot water to remove the papery smell, then add the ground coffee to the warmed brewer. Weigh both the coffee and the water on a kitchen scale — eyeballing it gives you a different cup every day. Pour roughly twice the coffee's weight in water over the grounds and wait 30-45 seconds; this is the "bloom," the step that lets trapped gas escape, and skipping it makes the extraction uneven.
Add the remaining water slowly, in a few stages and in a gentle circular motion, until you reach your total target; on an electric machine this step is handled by the device itself — you just need to fill the reservoir. Once brewing is done, remove the filter, give the cup a gentle stir, and serve it hot; as filter coffee cools, perceived sweetness drops and acidity becomes more noticeable, so avoid leaving it on a warmer for long after brewing.
Common Mistakes and How to Fix Them
The most common mistake is grinding the coffee long before brewing: ground coffee loses freshness fast once it's exposed to air, so grind right before you brew whenever possible. The second mistake is changing only the grind, without touching ratio or time, when the cup tastes off: if it's still unbalanced, change the ratio first, then the time, then the grind — one variable at a time — so you know what actually caused the difference. The third mistake is starting with cold or room-temperature water, or boiling it hard and leaving it open for a long time; both push you outside the target temperature range. Finally, a sour, flat cup is usually under-extracted, caused by a grind that's too coarse, water that's too cool, or too short a brew time; a bitter, dry cup is usually over-extracted, caused by a grind that's too fine, water that's too hot, or too long a brew time. Once you know which way the cup has drifted, fix one variable and try again. If you want to compare these steps on one specific piece of equipment, Kimor's V60 pour-over guide walks through the same steps in more detail for that single dripper.