Coffee is generally chemically acidic because its pH is below neutral. The About Coffee source incorrectly uses pH 4.6 as the general definition of acidity; that threshold belongs to particular food-safety classifications, not the basic chemical boundary. In ordinary aqueous discussion, pH below about seven is acidic.
A primary study comparing hot and cold coffee found similar pH values across its samples while measuring different titratable acidity. Those are distinct measurements. Perceived brightness, sour taste and a person's digestive symptoms are different again, so the label low acid needs an explanation of what was measured.
Roast, coffee selection, extraction and dilution can change the drink, but a coarser grind or cold brewing does not guarantee a symptom-free cup. Try brewing adjustments for flavor without treating them as medical treatment. If coffee causes recurring reflux or other discomfort, seek individual advice rather than assume the most expensive low-acid product solves it. The useful comparison is a clearly identified recipe or test result, not an undefined promise of gentleness.
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