I've been making cold brew at home for about a year now using a French press, but my stomach's been acting up lately. I've read that cold brew is supposed to be easier on your stomach than hot coffee, but mine still gives me acid reflux. Am I doing something wrong with my brewing method or should I try a different bean type?
Extending your brew time to 24 hours or longer will pull more of the good stuff out while leaving behind some of the compounds that trigger reflux - most people find that sweet spot around 18-24 hours works better than shorter steeps. You could also try a coarser grind, which reduces surface area and limits over-extraction of acids. Bean type does matter too; lighter roasts actually have more acid than darker roasts, so switching to a French or Italian roast might help more than your current beans. If it's still rough on your stomach after tweaking these, you might just be sensitive to caffeine itself rather than acidity, which is a different problem that cold brew won't solve.
The grind size matters more than people realize - if your grounds are too fine, they'll release more bitter compounds and chlorogenic acid even in cold water, which is actually one of the main culprits for reflux. Make sure you're using a coarser grind than you would for hot coffee, and also check that you're not reusing the same grounds or leaving them sitting in the liquid after your brew time is done, since that keeps extracting irritants.
Water temperature during the initial steep can make a bigger difference than people think. Cold brew typically uses room temperature or cold water, but if your stomach's still rebelling, try starting with water that's been sitting out or even slightly warm (around 60 - 70°F) for the first few hours, then switch to cold for the rest. This kickstarts the extraction without pulling out as many of the harsh compounds that develop over a really long cold soak.
That said, the other stuff matters too. Lighter roasts actually have more chlorogenic acid than darker roasts, so if you're currently buying light roasts thinking they're "gentler," that's probably backfiring. Switch to a medium or dark roast and see if that helps. You might also want to experiment with your water-to-grounds ratio - going a bit lighter on the coffee concentration means less acid per cup, which is obvious but easy to overlook when you're chasing that rich flavor.
One thing nobody's mentioned: try filtering your final cold brew through a paper filter instead of just pouring straight from the French press. A lot of the micro-particles and oils that remain can irritate your stomach, and a second filter pass catches that stuff. It takes five minutes and might be the cheapest fix before you overhaul your whole method.
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