I was recently asked by an online magazine about the chemistry of coffee. I thought it would be inappropriate to let these little tidbits of information rest unused, so here it is:
-The BEST flavor of the coffee bean dissolves in the first four minutes of brewtime. This is when the rich chocolate type flavors make their way out of the bean, after that, the hot water starts to dissolve more of the alkaloids, which is where all the astringency and bitterness of coffee come from. Considering most 10-12 cup drip coffee makers take as much as 10-15 minutes to brew, it’s easy to understand why most coffee made at home is nothing like the flavor from a cup made out of a quality coffee machine.
-Another challenge with coffee brewing is the inclusion of quinic acid. Some acid in coffee is good as it adds brightness to the coffee, but too much and it develops an overly acidic “burn a whole in your stomach” flavor. The problem, a chemical called quinide is dissolved into coffee during the brewing process. As coffee sits on the coffee burner at a temperature in excess of 170 degrees, the quinide transforms into the extremely sour quinic acid.
How do you solve these coffee quality issues at home?
If you haven’t made the leap to an espresso machine, or french press caraffe, the easiest way to speed up the brew time in your coffee maker is to preheat the water prior to pouring it into the coffee maker. Don’t take water directly from the hot water tap, because the longer water is at a higher temperature, the more dissolved gas it loses, and the blander/flatter your coffee will be. I recommend taking cold water, heating it in a tea kettle, and then carefully adding it to the coffee pot immediately prior to brewing. Your brew time will decrease dramatically, and you’ll get more of the good stuff, and less of the bad stuff in your java.
To fix the sourness, get a thermal caraffe, or air pot and transfer your coffee off the burner as rapidly as possible. The quicker you can get the coffee off the heat, the less excess quinic acid will form, and the more your coffee will taste like an incredibly rich and chocolate beverage, with a hint of brightness.