What's coffee processing?
The first of many steps in the journey to your cup.
Coffee processing is, essentially, how we remove the layers that surround the coffee bean (the seed). Coffee beans are at the heart of many coats - silver skin, parchment/hull, pectin, pulp and finally the outer skin/cascara - and all methods aim to extract the green bean from these layers prior to roasting.
Processing typically happens in one of three ways: natural, washed, and honey. There's also the rarer pulped natural.
Natural process, dry process, unwashed, or natural sundried all refer to the same method.
The ripe coffee cherries are set out to dry in the sun after picking, causing the fruit that surrounds the green coffee beans to dry out. To prevent spoiling, they are raked and turned over throughout the day and covered at night (and when it rains!), as well as lying in thin layer on high, raised beds. Once totally dry, the cherries are sent to mills in order to separate the beans from the outer layers, otherwise known as “hulling”.
This process emerged in areas of coffee production that don’t experience high humidity or frequent rain - like parts of west Africa - but our natural process beans hail from Brazil.
So what’s the impact on flavour?
Often, the byproducts of enzyme breakdown in the fruit are absorbed from the mucilage into the heart of the coffee bean, which can result in an incredibly distinct flavour profile. Natural processing typically lends fruiter, “funkier” flavours to the bean as it has more time to sit with the naturally occurring sugars in the cherry.
Our Brazil Esmeralda - Attendant’s House Espresso - has a deep, creamy body with notes of caramel, milk chocolate, vanilla and (fittingly) Brazil nut. The molasses body speaks to its natural process, and this sweetness is one of the many reasons we chose it as our daily grind. Try it in store or brew it yourself!
Washed process, meanwhile, focuses only on the bean, quickly discarding the fruit.
Also known as wet process, this method sees the cherries removed from the bean before they are dried. Firstly, the coffee cherries are sorted into varying ripeness levels, then run through mechanical "depulpers" - essentially, squeezed until the seed pops out. They are separated and the beans are placed in tanks.
Here, they are often soaked in water to break down and remove the remaining mucilage - fermenting - then cleaned with more water.
Fermentation is, in and of itself, a variable part of the washed process and can radically alter the flavour profile of the final cup. The longer the beans are left to ferment, the closer to a boozy flavour they get - hence some producers choosing extended fermentation to lend fruitier notes to their coffees, while still taking care to make sure their crop does not turn vinegary.
In terms of flavour profile, washed coffees are more acidic than their natural cousins, with greater clarity of flavour. Some people say they taste "clean", with vibrant notes like citrus and tart apple.
The majority of Attendant's washed coffees are for brewing filter; an extraction method that, again, lets the clarity of the bean sing. Why not try a bag of our Democratic Republic of Congo beans? Produced entirely by women, they burst with fruity notes of green grape and lemon sherbet, as well as sweet toffee.
As for honey, we don't currently stock any beans processed this way, but we'd be remiss if we didn't cover it in Coffee Processing 101!
Similar to the washed process but with fewer steps, honey is also called pulped natural or wet-hulling. The ripest cherries are picked and pulped, forcing the bean out from the fruit, but instead of being placed in fermentation tanks, the beans are then left to dry.
Varying amounts of mucilage has been left on the drying beans - this is what determines what type of "honey" the process is:
- White honey: 80-90% (or up to 100%) of mucilage removed
- Yellow honey: 50-75% of mucilage removed
- Red honey: 0-50% of mucilage removed
- Black honey: minimum mucilage removed
There's no actual honey involved in this process; the name comes from the sticky nature of the beans and the super sweet, mellow and smooth flavours of the final product. Notes of chocolate, brown sugar, spice and cedarwood are common.
And those are the big three!
The best part is that, of the main two, you never have to choose: we've always got at least one of each on the site.