All coffee has to be processed before it can be roasted and ultimately brewed and consumed. To understand why and how coffee is processed, we first have to go back to the coffee farm.
Even though we call them beans, coffee is actually the seed of a fruit - it’s not a bean at all. The fruit, often called a cherry is picked once ripe, usually by hand. Then it’s off to be processed.
Processing refers to the method by which the fruit is removed from the seed, and it can have a pretty noticeable effect on the final flavour in the cup. Processing methods lie somewhere on a spectrum between fully washed, a natural processing.
As the name suggests, washed process involves a lot of water. First, the cherry is depulped using a depulping machine. The removes the skin and most of the fruit, leaving a sticky layer of fruit mucilage stuck to the seed. To remove this last stubborn layer of fruit, the seeds are soaked in water in large fermentation tanks, where natural yeasts eat away at the fruit sugars, gradually breaking down the left over mucilage. Somewhere between 12 and 36 hours later, the clean coffee seeds (fine, beans then) are removed and dried.
Washed coffees tent to have very clean and bright flavour profiles with prominent acidity and good flavour clarity.
Natural processing is much more straightforward. The ripe cherries are picked and then left out to dry on concrete patios or raised beds for anywhere from two to six weeks. During this time the cherries are turned frequently to prevent mould and to make sure everything is drying at the same rate. When they’re good to go, the dried fruit is removed mechanically, leaving us with a dry coffee seed.
Natural coffees tend to have a nice fruity sweetness and good body, although sometimes they can exhibit some “funky” flavours that some people just can’t stand. This isn’t always the case and nice clean naturals are more and more common these days, but a funky natural can be a bit of a love-it-or-hate-it flavour.
Pulped Natural / Honey Processing
Pulped natural is sort of a middle ground between washed and natural. The skin (and some of the fruit in honey processing) is removed mechanically like in washed processing, but instead of soaking the seeds in a fermentation tank, they’re brought out to the patios to dry in the sun like in natural processing.
There are varying degrees of honey process (there’s no actual honey involved by the way) that indicate how much fruit has been removed. White honey process removes the most fruit, yellow a little less, red less still and black leaves the most fruit on.
Pulped naturals are a nice middle ground between washed and natural that tend to give a good sweetness and a nice body without sacrificing flavour clarity and cleanliness of flavour.
Next time, we’ll talk about origins and what they can tell us about a coffee.