How to Brew Chemex for One Cup (the Small-Batch Method That Actually Works)
Most Chemex recipes are written for 3 to 6 cups. That's what the Chemex was designed for — a tall, thick glass vessel with a paper filter bonded to it, made to brew a full pot for a household or a small group.
But a lot of us live alone, or we're the only one in our house drinking coffee right now. Brewing a 6-cup Chemex for yourself means 5 cups of cold coffee sitting on the counter, or a lot of waste.
You can absolutely brew a great cup of Chemex coffee for just yourself. The trick is to use the smallest Chemex (the 3-cup), get the ratios right, and accept that the brew is short — about 10 ounces, not a full pot.
This is the method we use when we want Chemex coffee but don't want to brew six of them.
What you need
Equipment:
- A 3-cup Chemex (the smallest one — about 1 pint capacity)
- Chemex paper filters (the bonded, thick ones — not generic cone filters)
- A gooseneck kettle (a regular kettle works but you'll have less control)
- A scale that reads in grams
- A burr grinder (blade grinders make this method inconsistent)
- A timer
Coffee and water:
- 18 grams of whole bean coffee (medium roast or lighter — dark roast is harder with this method)
- 300 grams of filtered water at 200–205°F
That ratio (1:16.6) is the standard for pour-over. It works for Chemex too, scaled down.
Why the 3-cup Chemex and not the 6-cup
The 6-cup Chemex is too tall and too wide for a single serving. The water drains too fast through the coffee bed — the brew ends up under-extracted, thin, and weak. The 3-cup Chemex has a smaller filter bed, which means the water moves through more slowly and extracts more evenly.
If you only have a 6-cup Chemex, you can still brew for one. Just understand the brew will be slightly faster and lighter than ideal. Use 18 grams of coffee and 300 grams of water — the same recipe — and accept that the cup will taste a little more delicate.
Step-by-step: brewing 10 oz in a 3-cup Chemex
Step 1: Rinse the filter (30 seconds)
Place a Chemex paper filter in the brewer, with the heavier three-ply side over the pour spout. Pour about 50 grams of hot water through the filter, saturating it fully, and discard the water in the carafe.
This does two things. First, it gets rid of the papery taste from the filter. Second, it preheats the Chemex. Both matter for the final cup.
Step 2: Grind and add the coffee (30 seconds)
Grind 18 grams of coffee to a medium grind — about the texture of coarse sand. Pour the grounds into the rinsed filter.
For a 3-cup Chemex, 18 grams fills the filter bed about halfway. That's the right amount. Too little and the water drains too fast. Too much and the bed chokes.
Step 3: The bloom (30–45 seconds)
Pour about 50 grams of water over the grounds, just enough to saturate them all. Start at the center and pour in a slow spiral outward, then back inward. The grounds will bubble and rise — that's the CO2 releasing. This is the bloom.
Let it sit for 30–45 seconds. Don't stir. The bloom is part of the extraction process.
Step 4: The main pour (1 minute 30 seconds)
Pour the rest of your water (about 250 grams remaining) in a slow, steady spiral. Start at the center, expand outward to the edge, then spiral back to the center. Don't pour directly on the filter paper — the water should hit the coffee bed, not the paper.
Pour in three or four pulses. Let the water level drop halfway between pours. The whole pour should take about 1 minute 30 seconds.
Step 5: The drawdown (1 minute 30 seconds)
After your last pour, the water will continue to drain through the coffee bed. This is the drawdown. Let it finish — don't pull the filter out early. The drawdown takes about 1 minute 30 seconds for a 3-cup Chemex.
The total brew time (bloom to end of drawdown) should be 3 minutes 30 seconds to 4 minutes. If it's faster than 3 minutes, your grind is too coarse. If it's slower than 4 minutes 30 seconds, your grind is too fine.
Step 6: Serve
Once the drawdown is complete, pull the filter out, discard it, and pour. Chemex coffee is best served immediately, but it'll hold its flavor for 20–30 minutes if you leave it in the carafe. After that, the cup starts to lose its brightness.
What to adjust if the cup tastes off
The cup is thin or sour. Grind finer. A coarse grind is the most common mistake with single-cup Chemex — people default to a coarser grind because they're used to making larger batches. The bed needs to be tight enough to slow the water down.
The cup is bitter or harsh. Grind coarser. The water is sitting too long in the bed, over-extracting.
The cup is weak. Add 1–2 grams of coffee. Don't go above 20 grams for an 18-gram recipe — too much coffee in a 3-cup Chemex will clog the filter.
The cup is flat. Check your water temperature. If the kettle has been sitting for a few minutes, the water may have dropped below 195°F. Reboil or pre-heat the water again.
Common mistakes with single-cup Chemex
Using too little coffee
The instinct when brewing for one is to scale the coffee way down. People use 8 or 10 grams in a 3-cup Chemex and end up with a thin, weak cup. The filter bed needs enough coffee to slow the water down. 18 grams is the minimum for a 3-cup Chemex.
Using the wrong grind size
For single-cup Chemex, the grind should be on the finer side of medium. Think "table salt," not "raw sugar." If you have a Baratza Encore or a Fellow Ode, this is around setting 8–10. If you're eyeballing, err on the side of finer.
Pouring water on the filter paper
The water should always hit the coffee bed, not the paper. Pouring on the paper bypasses the coffee and you lose extraction. If you're seeing channels of clear water running down the side of the filter, your pour pattern is off.
Rinsing the filter with cold water
The rinse water should be hot — the same temperature as your brew water. A cold rinse leaves the filter cool, and the first part of your brew extracts slower than the rest.
Not using a scale
Measuring by spoons is unreliable for pour-over. Coffee density varies. 18 grams of one coffee might be 1.5 tablespoons; 18 grams of another might be 2 tablespoons. Use a scale.
What we use
At home, we use a 3-cup Chemex for one-cup brewing about 4 days a week. The rest of the time we use a Clever dripper (see our Clever dripper guide). The Chemex makes a cleaner, more tea-like cup. The Clever makes a fuller-bodied cup. They're different tools for different moods.
For coffee, we use a Costa Rica or a Colombian single origin at a medium roast. The lighter the roast, the more the Chemex paper filter highlights — citrus, florals, bright fruit. Darker roasts lose some of that.
The takeaway
A 3-cup Chemex is the right tool for a single serving. The recipe is 18 grams of coffee, 300 grams of water at 200–205°F, ground at a medium setting, brewed for 3:30 to 4:00 total. Get those four variables right and the rest is just practice.
If you're new to Chemex, give yourself 3 or 4 brews before you decide whether you like it. The first cup is rarely the best cup. The paper filter, the slow pour, the longer brew — they all combine to make a cup that's distinctly Chemex, and it takes a few tries to land.
— Seraphina, Cozy Sips
If you'd rather skip the manual pour, the Clever dripper is a great alternative — same quality, less attention required.