When it comes to words that usually describe coffee, rarely do we see the words "acidic" or "bitter" among them. They carry less-than-positive connotations, as we've often been trained to prize smoothness and sweetness in coffee. But in reality, the right amount of acidity lends balance, complexity and a little pop to the flavor of high quality coffee that we'd really miss if it wasn't there. Hear us out: Consider the lemon, one of the universal workhorses of the kitchen. While we might not eat it by the slice like we do with oranges, a pinch of its piquant zest does wonders for baked goods, and a squeeze of its bright juice makes everything from iced tea to garlicky pasta come to life. Lemon's citrus sharpness makes most everything else it touches taste richer and bolder. Without it, so many of the world's cuisines would fall a bit flat.
The taste receptors on our tongues that detect sweet, salty, sour and bitter (and some argue, savory) long to all be lit up like a Christmas tree. So things that are just sweet don't often have that certain spark or the flavor contrast we crave. A mass produced milk chocolate bar doesn't intrigue the palate like a square of cacao-dense dark chocolate. Real cocoa beans are mighty bitter, and it is that element mingling with the added sugar that makes good dark chocolate so wonderful. There's a new book out about this exact concept, simply titled Bitter, by chef and writer Jennifer Mclagan. She argues that bitterness is an under appreciated flavor in North America but that due to growing interest in coffee, chocolate, craft IPA-style beers, and leafy greens, we as a culture are finally starting to understand what lies beyond our favored salty and sweet. That's right: bitterness is trending.
So, when it comes to coffee, some levels of acidity and even bitterness are not uniformly bad. Many coffees beans grown at high altitudes - generally considered of higher quality than those grown lower - carry with them tasting notes like "bright," "dry," or "effervescent," which are all basically classed up ways of talking about acidity. For the record, this isn't the same thing as pH-based acidity. In fact, on the pH scale, properly brewed coffee is less acidic than orange juice, beer, and most sodas (!). The acidity we're talking about is all in the flavor profile. Some other factors that come into play besides growing altitude and region are whether the coffee beans are washed (fermented) after they're picked, and roasting techniques. Washed coffees often turn out more acidic than unwashed, and lighter roasts tend to be more acidic than darker roasts.
There's a fun tasting exercise over at FWx.com (Food&Wine Magazine's hip, young counterpart) that we recently came across that nicely illustrates the benefits and nuances of acidity. They suggest buying 5 different varieties of apple - red delicious, granny smith, fuji, pink lady and mcintosh - slicing them up and putting them on separate plates. You're supposed to taste each one, first while holding your nose, and then like normal - this helps you to realize how instrumental the sense of smell is to fully experiencing flavor. The idea is that by tasting apple varieties side by side, you can train yourself to consider the nuanced differences beyond their shared apple-iness. So much of that has to do with their levels of acidity and sweetness.
For extra credit, put the apples in order from most to least acidic and ask yourself which ones you most enjoyed. There is a matter of personal preference involved - some people generally veer towards sharp, bright acidity (shout outs to all the Sour Patch Kids lovers out there!), and some prefer rounder, milder, or sweeter flavors. If you become acquainted with which level of acidity you tend to like, let one of our baristas know the next time you're in HubBub. This info can help them steer you towards the perfect coffee for you. There is no right or wrong, only a chance to expand the sensitivity of your palate and try new things!
Apple photo by Dan McKay, used under a Creative Commons License