You're not imagining it. When the temperature drops, your French press routine can go sideways. The air is cold, the counter is cold, the press itself is cold. You heat water, but by the time it hits the grounds, it's already lost a few degrees. That's the first problem.

Coffee extracts best between 195°F and 205°F (90-96°C). If your water is cooler, you get under-extraction—the acids come out first, the sugars never fully release, and you're left with a sour, sharp cup. It's not your beans; it's your brew temperature.

The second problem is grind size. Most people grind coarse for French press, which is right, but in cold weather, coarse grounds extract even slower. The water cools faster, so the grind needs to be a touch finer to compensate.

The third problem is time. You might be steeping for 4 minutes, but in cold weather, extraction is slower. You need to give it a bit more time to pull out the sweetness.

These three mistakes share one root cause: you're not keeping the brew hot enough for long enough.