The chemistry of coffee
Updated: Nov 22, 2019
More than half of adult Americans drink coffee every day, making the US the 8th highest coffee consuming country in the world. So there must be something great about coffee if so many people are into it. You might have guessed the answer: it’s pretty delicious!
Chemistry: making coffee taste great!
Coffee is a chock-full of compounds that contribute to this taste. While the exact composition of a cup of coffee will depend on the origin and roast of the beans, there are a number of molecules - and consequently tastes - present in most coffees.
The first molecule that jumps to mind when you think coffee, is probably “caffeine”. Caffeine is indeed part of what makes a lot of people love coffee, it’s a natural stimulant that blocks neuroreceptors from interacting with the sleep chemical edenosine, and therefore makes you feel more awake and alert. It is actually a plant toxin, and though it is not toxic to most people (though some people can be very sensitive to caffeine), it can negatively affect your sleep.
More than caffeine alone
Luckily, there are other compounds in coffee that contribute more to the taste. Quite a few of those compounds are acids, which include quinic acid, citric acid, chlorogenic acid, phosphoric acid, and acetic acid. These give coffee a “sour” taste. While you might not like too much sour in your coffee, a little bit creates a good balance between all the other things you are tasting. In addition, some acids, such as 3,5 dicaffeoylquinic acid, act as an antioxidant.
That’s not where the beneficial compounds in coffee end; it also contains theophylline, which is a mild caffeine-related stimulant that acts as a muscle relaxant and is present in some medicines to treat the symptoms of bronchitis and asthma.
Another compound present in coffee is 2-ehtylphenol, which gives coffee its slightly medicinal, tarry smell. Coffee is not actually a medicine, but it does contain niacin, or vitamin B3, and vitamins are generally good for your health. Niacin is the result of another compound, trigonelline, breaking down at higher temperatures. Trigonelline itself gives coffee a sweet, earthy taste. So, double wammy, good taste and healthy vitamins!
Contributing strongly to the taste as well is a molecule called acetylmethylcarbinol. This long named-chemical is present in butter, and makes coffee taste - you guessed it - buttery. There are a lot more molecules present in coffee, some of which in large quantities might even sound unpleasant (looking at you, demethyl disulfide which smells like garlic, and putrescine which smells just like it sounds - putrid), but together, they contribute to the complex and delicious flavor of coffee!
There are a lot of different tastes in coffee and as with many things: finding the right balance is what makes it delicious!
What about decaf coffee?
During the decaffeination process, caffeine is extracted from the beans. Unfortunately, sometimes other molecules that contribute to the flavor of coffee, are removed as well! The trick to a good cup of decaf is maintaining the deliciousness of coffee. With the Decaf Pouch, you can easily remove the caffeine without losing any of the taste!
Written by Valerie Bentivegna
Extract on coffee from This is what you just put in your mouth? By Patrik Di Justo, Three Rivers Press (a division of Penguin Random House LLC), 2015
Coffee statistics: http://www.e-importz.com/coffee-statistics.php
More about the chemistry of coffee: https://www.acs.org/content/acs/en/acs-webinars/culinary-chemistry/coffee.html