Nectar of the gods. Liquid joy. My favorite vice. All these words describe coffee for me.
But, they don't help me articulate what I like or don't like about the taste of a particular brew. So, I decided it's time for a little coffee bean edumacation, yo!
First the Bean
Coffee beans come from two types of coffee plants: arabica or robusta. For you gardening types, coffee belongs to the botanical family Rubiaceae, genus Coffea, and it thrives in tropical regions around the world below the Tropic of Cancer and above the Tropic of Capricorn (picture a thick belt all around the Earth's equator).
Arabica coffee grows at higher altitudes, and robusta (also known as coffea canephora) grows at lower ones. Arabica beans contain less caffeine and 60 percent more lipids (fats) and sugars than robusta, so their flavors are more refined and less likely to taste sludgy or bitter upon roasting. Robusta beans give higher yields per plant, are more resistant to disease than arabica, and contain about twice the caffeine content by weight (thought to deter those pests and diseases!). Instant coffees are commonly blended from robusta beans.
Which brings us to blended versus specialty coffees. I'm going to guess you can figure out what blended means: roasters will select more than one type of bean to source and roast together, in order to deliver a consistent flavor profile time after time. Specialty coffees are cultivated, harvested, and roasted in ways to present and promote coffee as an artisanal foodstuff, not a commodity. They often comprise a single-type, even a single-origin / micro-climate bean. If you're familiar with wine-tasting, the concept is analogous to assessing the terroir of a wine.
Next the Roast
There are whole books written about roasting coffee beans. Classes and Certifications administered, too. I'm not going that far. Mostly, I'm interested in definitions of roasts and how they tend to result, taste-wise, in my cups of java. But, first things first.
Coffee starts as what's called a cherry. Inside the ripe blueberry-sized fruit is its seed, a green coffee bean. It's the pit, really, but who tends to equate liquid nectar with roasted pits, right?
Coffee beans are separated from their cherries via one of three methods: a Washed (Wet) process, a Semi-Washed process, or a Natural (Dry) process. If you'd like to get your Coffee Geek on big time, check out the book How to Make Coffee: The Science Behind the Bean by Lani Kingston. It has enjoyably thorough descriptions of these methods. And, if you find yourself called to become a Master Roaster, you'll no doubt revel in the subtleties of roasting a Wet-processed Guatemalan arabica versus a Dry-processed one.
But, for the sake of us mere coffee slurpers, let's just say we've got some processed green coffee beans in front of us, and we want to know how they might be roasted.
In a big heated drum, that's how. During the roast, coffee beans undergo chemical and physical changes that affect their color, size, taste and smell.
Mmmmm, roasting coffee smells are the best, aren't they? I might drool as I think about them. I digress.
Roasts range from - wait for it - Light to Dark. You knew that, didn't you? Did you know about the cracks? Let me tell you about cracking coffee beans.
The beans are in the heated drum. Check. The temperature inside them is rising. Check. Once the temperature reaches about 400° F, those puppies expand in size and - Crack #1! Stop right there, and you have a Light Roast. The beans will not look dark or oily, and the roasted bean will retain most of its origin flavor and caffeine.
If you keep the heat on, the beans will hit Crack #2 at about 435 - 445°F. Dark Roasts stay in the heat until or just past Crack #2. But, a Medium Roast will fall in the middle. Your roaster might like to pull their Medium Roast beans right before the second crack. Or, right at it. It's an art, not a science.
As far as resulting tastes go, I like to think: lighter roasts taste "bean-ier;" darker roasts taste "roast-ier."
I'm always a sucker for a dark roast. But, from my research for this post, I think I'm going to have to try more Medium and Light roasts to expand my palate!
Finally the Taste
Traditionally in coffee tasting, or cupping, there are four categories: aroma, acidity, body, and flavor.
Smell much? Our sense of smell informs our sense of taste. Our tongues can taste only salty, sweet, bitter and sour; but, our noses can detect thousands of smells. So, take a deep whiff of your black gold before slurping your first sip and spray the coffee across your palate and tongue to gauge as much flavor and aroma as possible. Sample words to describe aroma include spicy, nutty, floral, and earthy.
Acidity is similar to the idea of carbonation in soda. - www.kaladicoffee.com
Nobody seeks out flat soda, usually. But, nobody wants to be overwhelmed by fizz either. At ideal acidity, the taste of a coffee is fresh, lively, and bright with a clean finish. It has a little snap. At too acidic, the taste runs to bitter and has too much bite (I just pictured a coffee cup with teeth around its edge - hardy har har).
Acidity is determined both by the type of bean and how it's roasted. The darkest roasts taste the least acidic. Coffees with low acidity feel smooth in your mouth and tend to linger.
Body is the weight or thickness of the coffee on your tongue. Me, I love a cup of espresso that seems thick enough to stand a spoon in! But, I also prefer the feel and taste of whole milk versus non-fat. Non-fat just tastes like white water to me.
Actual roast/bean flavor descriptions I've come across include: Toasted Walnut, Chocolate, Golden Raisin, Maple Syrup, Cocoa Nib, Currant, Vanilla, Dried Fig, Blackberry, Hazelnut, Malt, and Caramel. I don't know that I'd discern Dried Fig in any coffee, but I'll be on the lookout from now on.
Big sigh. Wasn't that all informative? Makes you want to go out and taste some coffee right now and grab a friend - or a stranger even - and Describe How Your Coffee Tastes to them, doesn't it?
Get to it then, and let me know how it goes.