My ratio kept tasting wrong until I started weighing the water instead of the coffee
Been brewing on a Chemex for about two years and for most of that time I was convinced the problem was my grind size. Too coarse, too fine, adjusted, adjusted again, read every guide I could find. The brew always came out either a little flat or weirdly bitter with this thin, almost watery finish that I could not explain.
Turns out I was measuring coffee by weight but eyeballing the water. I would fill the kettle, pour what felt like the right amount through the bloom and the main pour, and call it done. Never once thought about how much water I was actually using. When I finally put my scale under the whole setup and tracked both inputs together, I realized I was consistently overshooting the water by somewhere between 40 and 70 grams depending on the day.
That inconsistency explained everything. Some mornings it tasted fine and I thought I had finally dialed it in. Other mornings it tasted weak and I blamed the beans. It was just sloppiness in how I was tracking one half of the ratio.
What actually fixed it for me was setting a target weight before I even start heating water. Right now I am using 42 grams of coffee to 700 grams of water, which lands around 1:16.6. The bloom gets 90 grams, I wait about 45 seconds, then the rest comes in two slow pours. Time from first pour to drawdown is usually around four minutes.
The Chemex does seem to reward patience with the pour speed more than any other brewer I have used. Slow and steady lets the grounds stay relatively level and the drawdown stays clean without going too fast. If I rush the pour and agitate the bed, the cup gets murky and the clarity that makes this brewer worth the hassle just disappears.
Curious whether others here track water temp as precisely as the grind and ratio, or whether you treat it more loosely. I have been landing between 93 and 96 Celsius and have not noticed a huge difference within that window, but I also have not done anything systematic to test it.