Embrace the terroir. Don't fear the fruity acidity.
I've seen people scream that their coffee is "acidic" when it's just fruity. This is a thorny topic for many; I've had comments from many people who say they'd rather their coffee was too bitter than too acidic. I intend to make a distinction between two aspects of taste, fruiter flavours and mouth-puckering sourness. For many coffee drinkers (including me!) the inclusion of some fruity acidity is a welcome addition. Personally I love the more-ish feeling of light acidity in my cup, perhaps invoking a citrus, berry or stonefruit taste. COupled with some sweetness and body, it can invoke a jammy flavour note that is sought out my many tasters. Additionally, a fruity finish to a cup makes me want more! This is dramtically different from anything that makes the mouth pucker; that's often a flaw in the coffee making process (often underextraction of the solubles). Somtimes it's in the roast itself; in a lighter roast style, possibly this is evidence of too light a roast and maybe blending with a darker-style bean would mitigate the unpleasantness of the sensation if it troubles you. If you're not comfortable with the fruit in a lighter roast style, consider a
more medium style, which may add more body and bitterness to offset that fruit acid and sweetness. It's fine to not appreciate lighter roast styles; for a long time I didn't. Grind size may be a factor if it tastes underextracted. try a slightly finer grind, it may help.
Even a darker style can have some acidity in it depending on the coffee origin. Ethiopian, Kenyan and some other eastern African origins tend to be fruitier, especially when grown at higher altitudes. some Columbian coffees have the same trait, one that many coffee lovers seek out. There's a balance to be met between the natural bitterness of coffee in general, and the fruit notes from the terroir. I do recommend trying some coffees from the origins mentioned earlier; you may be surprised at the difference a little fruit acid can contribute to the overall balance of flavour in the cup. I actively seek out those coffees. Thankfully that balance is present in my daily driver Nicaraguan, and my local cafe's medium roast style has a similar flavour profile, evident even through the milk in a cappuccino or flat white. Experiment, talk to your roaster or barista honestly, they may have suggestions for what to try next, or how to improve your brewing method.
If you're put off coffee because you worry it makes your stomach sour, fear not. A little tingle of fruitiness is not going to give you heartburn. Any heartburn you experience may not be down to acidity in your coffee cup, rather some other element. It could be you're drinking it too hot or too cold. Our perception of flavours can alter with temperature. if you have to blow a gale across your coffee to cool it enough, it is too hot to begin with. Keep it to below 80°C before drinking, and ideally between 55° and 70°. The human mouth is not equipped to taste well at temperatures higher than that anyway, and you are certainly not getting the best flavour from your coffee as it approaches scalding point. Let it sit a few minutes, for goodness' sake, it won't kill you to be patient.
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