Coffee affects reflux through two separate properties: caffeine relaxes the LES, and coffee itself is acidic, which can directly irritate the esophagus in people who already have some inflammation there. For some people, this makes coffee one of the most reliable triggers; for others, it causes no noticeable issue at all, which is part of why blanket advice to "just quit coffee" doesn't land the same for everyone. If coffee is a suspected trigger, a few adjustments are worth trying before eliminating it entirely: drinking it with food rather than on an empty stomach, choosing a less acidic roast (darker roasts are often lower in acid than light roasts), reducing quantity rather than cutting it out, or switching to cold brew, which tends to be less acidic than hot-brewed coffee.
