Why Is Coffee Bitter?

Coffee has a unique and, for some, an acquired taste. Caffeine plus two compounds created when coffee is roasted result in a bitter taste that is unique to java. Caffeine is the minor partner in the bitterness endeavor. The main two culprits are both antioxidants, which are the chemicals responsible for so many of the health benefits of coffee. The first antioxidants are chlorogenic acid lactones. These chemical antioxidants are created in light and medium roast coffees. A more potent cause of bitter taste in coffee comes from phenylindanes which are created in a dark roast coffee. But, there is more to the story than how you roast your coffee. How you prepare coffee is important as well.

Leaving Coffee in the French Press Too Long

Whether you like a light, medium or dark roast, the longer the water is in contact with the coffee grounds the more chemicals, and bitterness, you will extract. The best example of this phenomenon is when you use a French press and make more coffee with a than you will use right away. You let the coffee and grounds remain in the French press and return later for another cup or two. The odds are that more of the bitter antioxidants will have dissolved into the water making your second and third cups increasingly bitter.

Maximum Coffee Ground Surface Area

You could make coffee from putting whole roasted beans in hot water. But, you would need to wait a really long time for the antioxidants and caffeine to leach out and even then you would end up with an awfully weak cup of coffee. The reasons we grind coffee are to increase the surface area of coffee that is exposed to the hot water and to decrease the distance that caffeine and antioxidants need to move to get out of the coffee grounds and into the water. If you do not like bitter coffee, you need to be careful how finely you grind your beans. Very finely ground coffee gives up its caffeine and antioxidants quickly and thoroughly. This is a common reason why your coffee is bitter.

Hotter Water Dissolves Coffee Ingredients More Thoroughly

One reason that cold brewed coffee is less bitter than brewed coffee is that the bitter antioxidants are not as quickly or thoroughly removed from the grounds. The hotter the water you use to brew coffee the more antioxidants you will get in your cup. When you boil water to make coffee you have water at 212 degrees Fahrenheit if you live at sea level. If you live in the Eje Cafetero in Manizales, Colombia your boiling water reaches 198 degrees Fahrenheit. If you live at lower elevations and want to avoid coffee that is too bitter let the water sit a few minutes after removing from the stove. The ideal temperature for brewing coffee according to the National Coffee Association is between 195 and 205 degrees Fahrenheit. The folks in Manizales at 7,500 feet altitude can make their coffee with boiling water.  Those of us who live in the low lands should wait a minute or two to let our just-boiled water cool ever so slightly.

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