has a predetermined lifecycle: You pour a steamy mug of joe, set it down next to your laptop to refrain from burning your tongue, and before you know it, an hour has passed and your coffee is stone cold. You pop it in the microwave to nuke it for a few seconds, press the cup to your lips and grimace. It’s bitter. Bitter in a way that makes you wonder if someone poured a Romeo and Juliet-style vial of poison into it.
Green coffee contains chlorogenic acids, and the roasting process breaks those down into quinic acid and caffeic acid. While chlorogenic acid has a bitter taste, quinic acid and caffeic acid both have an even more pronounced bitter, astringent flavor.“All coffee has some amount of bitterness,” Rosenberg said. “But in freshly brewed coffee, there is also plenty of sweetness and acidity that balance the bitterness and create a complex and delicious-tasting coffee.
There are also tiny particles floating around in most cups of coffee ― especially if you’ve used a French press ― that continue to brew and get more bitter when you reheat your coffee. Rosenberg said brewed coffee will taste best if consumed within an hour or 90 minutes of brewing, no matter what.Every type of roast will taste more bitter upon reheating it, to a certain degree. But Rosenberg said a dark roast coffee’s bitterness will be even more pronounced.
Rosenberg said you should also make sure to preheat whatever container you’re brewing into, whether you’re doing a manual brew or a Mr. Coffee. Heat up some hot water in a kettle, then pour it into your pot, swirl it around a little and dump it out before you brew into it ― voila, your pot will be warm. The same goes for the mug you’re drinking out of. Take your mug and slosh a little hot water around in it to maintain that temperature even better.