So you got a siphon brewer because it looks cool and makes a clean cup. But the first few batches taste sharp, almost like lemon juice with a coffee background. Don't toss the brewer. Sour siphon coffee is a fixable problem, and it's usually simpler than you think.

The culprit is under-extraction. That's a fancy way of saying the water didn't pull enough flavor out of the grounds. When that happens, the bright, acidic notes dominate, and you get that sour punch. It's not a bad bean problem—it's a technique problem.

Here's how to fix it, step by step.