Acidity is part of coffee's sensory vocabulary, often expressed through citrus, apple or other fruit comparisons. CoffeeBox discusses natural acids, including chlorogenic acids and several other organic acids. Their presence does not mean a cup has spoiled, but a sour taste alone also cannot establish freshness or diagnose a specific brewing fault.
Perceived sourness depends on the whole beverage, including aroma, sweetness, bitterness and concentration. Chemical measures such as pH and titratable acidity answer different questions and should not be used interchangeably. A fruit descriptor is therefore not a measurement of a particular acid, and a dark roast does not become chemically acid-free.
When a cup seems unpleasantly sharp, record the coffee and recipe before changing a single variable. Grind, ratio, water, roasting and the particular lot may all contribute. You do not have to enjoy strong acidity to appreciate coffee, and disliking it does not prove inadequate training. Describe the experience first, then compare a deliberate recipe change.
The conversation
A good question can make a better brew.