Ko & Co Coffee

September 2025

Getting first crack timing right (eventually)

For the first few months we roasted by ear and by vibes, which worked right up until it didn't. The batch that changed things was a Guatemalan we'd bought specifically because the bag said "bright, floral, tea-like" — and what we got out of the roaster tasted like a burnt tea bag. Not floral. Not bright. Just sad.

The problem, we eventually figured out, was that we were reacting to first crack instead of anticipating it. By the time you actually hear it clearly over a fan and a pan sizzling, you're already a good 20–30 seconds into it, and if you're aiming for a light-to-medium roast that's most of your development time gone before you've even started the stopwatch.

What we changed

Two things, both boring:

Our rough timeline now, for a light-medium roast in our setup: charge at 0:00, yellowing around 5:30–6:00, first crack starting somewhere around 8:30–9:30, and we pull it 60–90 seconds after first crack starts depending on how it's smelling by then.

Every roaster and every batch size shifts these numbers around, so treat this as "what worked for us" rather than a recipe. The bigger lesson was just: write the times down, every batch, even the bad ones. We didn't do that for months and it cost us a lot of repeat mistakes.

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