Chemex Brewing Guide: How to Make a Clean, Sweet Pour Over

Why the Chemex Tastes Different

Ask ten pour over drinkers what makes the Chemex special and you'll get ten answers, but they all circle the same thing: the filter. That thick bonded paper strips out oils and fine particles, leaving a cup that tastes clean, tea-like, and unusually sweet when you get it right. It also clogs mercilessly when you get it wrong. This Chemex brewing guide walks through the whole process — grind, ratio, pour schedule, and the fixes for the two problems everyone hits.

What Makes It Different

The Chemex is a single-piece hourglass carafe with a built-in cone and a signature air channel — the little groove in the neck that lets displaced air escape while you pour. Its filters are roughly 20–30% heavier than a standard V60 paper, which is exactly why the cup tastes so clear.

That thickness comes with a trade-off. Water moves through slowly, so the brew is more forgiving of pour technique and far less forgiving of grind size. On a Chemex, grind is the main dial you turn.

If a V60 is a sports car that rewards precise steering, the Chemex is a heavy touring car — smooth, stable, and slow to change direction.

What You Need

• Chemex (the 6-cup is the everyday workhorse)
• Chemex bonded filters — square or circular, both work
• A burr grinder
• A gooseneck kettle
• A scale and a timer
• 42 g of coffee and 700 g of water for a full 6-cup brew

The Recipe: 1:16.5 for a 6-Cup Chemex

Start with a 1:16.5 ratio — 42 g of coffee to 700 g of water. It lands between the bright, thin end of the spectrum and the heavy, muddled end, and it scales cleanly if you brew smaller.

1. Rinse the filter properly

Fold the filter so the triple-layered side sits against the pouring spout, then rinse it with hot water until the paper is fully saturated and the carafe is warm. Dump the rinse water. This is not optional on a Chemex — unrinsed heavy paper genuinely tastes like paper.

2. Grind medium-coarse

Aim for coarse sea salt: noticeably coarser than drip, slightly finer than French press. Too fine and the heavy filter chokes, stalling the brew past five minutes and pulling out bitterness. Fines are the enemy here, which is why a burr grinder matters more than an expensive kettle.

3. Bloom with 90 g for 45 seconds

Add the grounds, level the bed, tare the scale, and pour roughly twice the coffee weight in water — about 90 g — starting at the centre and spiralling out. Give it a gentle swirl so every ground is wet. You'll see the bed puff up as CO2 escapes; fresh coffee blooms dramatically, stale coffee barely moves.

4. Pour in stages

After the bloom, pour in three roughly equal additions:

1. To 300 g, in slow concentric circles
2. To 500 g, once the bed has drawn down about halfway
3. To 700 g, finishing before the 3:00 mark

Keep the pour inside the bed and off the paper. Water that runs down the filter wall bypasses the coffee entirely and thins your cup.

5. Target a 4:00–5:00 total brew

The last drips should land somewhere between four and five minutes for a full carafe. Give the Chemex a swirl before serving so the brew is evenly mixed, then pour immediately — it tastes best as it cools into the 60°C range, where the sweetness really shows up.

Water Temperature and Bed Depth

Use water at 93–96°C for light and medium roasts, and back off to about 90°C for dark roasts, which give up their solubles too eagerly and turn ashy.

Bed depth matters more on a Chemex than most brewers because the cone is wide. Brewing a tiny 20 g dose in a 6-cup creates a shallow bed that water races through unevenly. If you regularly brew for one, either buy the 3-cup or accept that you'll need a slightly finer grind to compensate.

Fixing the Two Classic Chemex Problems

The brew stalls

If you're past five and a half minutes and water is still sitting on top, the grind is too fine — or your filter has sealed itself against the glass. Coarsen up a notch or two and make sure the folded filter isn't pressed flat against the wall in the channel area.

The cup tastes thin and sour

Sourness plus a fast draw-down means under-extraction. Go one step finer, pour a touch more slowly, and check that your water isn't sitting well below 93°C. A weak, watery cup with no sourness is usually just a ratio problem — try 1:15.

Cleaning and Care

Rinse the carafe with hot water after every brew and give it a deep clean weekly with a coffee-specific detergent. Oils build up invisibly in the neck and go rancid, and rancid oils will flatten even a perfect brew. The Chemex is glass, so avoid thermal shock — no boiling water into a cold-from-the-fridge carafe.

The Takeaway

A great Chemex cup comes down to three things: rinse the heavy filter, grind medium-coarse, and finish your pours by three minutes so the brew lands between four and five. Get those right and the Chemex does what nothing else quite does — it makes a big, shareable carafe of coffee that stays clean and sweet down to the last cup.