Filter coffee is now considered the standard by most specialty coffee experts. It offers a clear cup that fully reveals the bean's aromas while retaining unwanted oils thanks to the paper filter (Tverdal et al., 2020).
Good news: you don't need high-end equipment to make it well. Four parameters are enough to master. Here's how.
What you need
A filter holder, such as a V60 (Hario), Chemex, Kalita Wave, or a simple filter coffee maker. A suitable paper filter. A scale that measures to the gram. A kettle (ideally a gooseneck for better flow control) and, if possible, a thermometer or a temperature-controlled kettle. A grinder, ideally a burr grinder: grind consistency is more important than fineness.
And of course, freshly roasted, whole bean coffee.
The four parameters that make all the difference
Coffee to water ratio
This is the first variable. The Specialty Coffee Association (SCA), a global reference in specialty coffee, recommends a ratio of 1:16 to 1:18, meaning 1 gram of coffee for 16 to 18 grams of water. The European Coffee Brewing Centre advises about 60 grams of coffee per liter of water.
To start simply: weigh 15 grams of coffee for 250 grams of water (1:16.7). Then adjust according to your taste: less water for more body, more water for more clarity.
The grind
For filter coffee, aim for a medium grind, comparable to granulated sugar. Too fine, the water passes too slowly, the coffee becomes bitter (over-extracted). Too coarse, the water passes too quickly, the coffee becomes acidic and flat (under-extracted).
This is the most powerful parameter for adjusting your cup. If it's bitter, coarsen the grind. If it's sour, refine it.
Water temperature
The SCA recommends water between 92 and 96°C. Without a thermometer, boil your water, then wait 30 to 45 seconds before pouring. At this temperature, extraction is optimal: hot enough to release complex aromas, but not too hot to avoid bitterness.
Avoid directly boiling water, which "burns" the coffee, as well as water that is too cold, which leads to under-extraction.
Extraction time
For a standard filter coffee (15g of coffee), the total extraction should last between 2 minutes 30 and 4 minutes, including the initial phase (the bloom).
If your extraction is faster, your grind is too coarse. If it's slower, it's too fine.
The 5-step technique
Step 1. Rinse the paper filter with hot water. This removes the papery taste and preheats the vessel. Discard this water.
Step 2. Pour the ground coffee into the filter. Weigh the assembly on the scale and zero it.
Step 3. The bloom. Pour about twice the weight of the coffee in water (i.e., 30g of water for 15g of coffee), uniformly wetting all the grounds. Wait 30 to 45 seconds. The coffee expands and releases its CO₂. This phase is essential for homogeneous extraction.
Step 4. Pour the remaining water in several passes, using slow circular motions, starting from the center outwards, without touching the edges of the filter. Avoid pouring too quickly or too forcefully.
Step 5. Once the water has completely drained (between 2:30 and 4:00), your coffee is ready. Serve immediately.
Common mistakes
Using coffee ground several days ago. Volatile aromas degrade within a few hours after grinding. Grinding just before extraction transforms the cup.
Neglecting water quality. Water makes up over 98% of your cup. Hard or highly chlorinated water alters the taste. Choose filtered or lightly mineralized water. The SCA recommends water with a total mineralization rate between 75 and 250 ppm.
Skipping the bloom phase. Without this pre-infusion, the coffee is extracted unevenly, resulting in a hollow and unbalanced taste.
How to adjust to your taste
If your coffee is too bitter: coarser grind, slightly cooler water, or a more diluted ratio (1:17, 1:18).
If your coffee is too acidic or flat: finer grind, hotter water, or a more concentrated ratio (1:15).
Only change one thing at a time. Taste. Adjust.
In summary
Good filter coffee comes down to four benchmarks: 15 grams of coffee, 250 grams of water at 93°C, medium grind, 3 minutes of extraction. The rest is built by ear and palate.
The Helioce approach
At Helioce, our coffees are roasted in small batches, to a medium degree, to reveal the full richness of each origin using the filter method. Our advice: grind on demand, take care of your water, take your time. Filter coffee is one of the most beautiful ways to hear what a bean has to say.
References
European Coffee Brewing Centre. Certification Standards for Coffee Brewers. ECBC.
Hendon, C.H., Colonna-Dashwood, L. and Colonna-Dashwood, M. (2014). The Role of Dissolved Cations in Coffee Extraction. Journal of Agricultural and Food Chemistry, 62(21), 4947–4950.
Rao, S. (2014). The Coffee Roaster’s Companion. Self-published.
Specialty Coffee Association. Coffee Standards / Golden Cup recommendations. SCA.
Tverdal, A., Selmer, R., Cohen, J.M. and Thelle, D.S. (2020). Coffee consumption and mortality from cardiovascular diseases and total mortality: does the brewing method matter? European Journal of Preventive Cardiology, 27(18), 1986–1993.