Welcome to Part II in our Coffee Matters series, where we’ll talk about coffee processing methods and their impact on your cup.
The humble coffee bean actually starts its life as a fruit similar to a cherry. Before it can be roasted, the skin and pulp must be removed and the seed dried.
The way this is done is called the “processing method,” and it is one of the biggest factors affecting the flavor of your coffee – whether it wet or dry processed will make a bigger difference than whether it is from Brazil or Ethiopia.
But what does that actually mean? Read on!
Natural or dry process
This is the oldest approach to processing coffee. The whole fruit is sundried in thin layers on patios or raised drying beds, being regularly raked or turned by hand to ensure even drying. This usually takes around a week but depending on weather conditions, it could take up to four to reach the optimum moisture content. The skin and pulp is then easily removed from the bean.
During the drying process, the beans are imbued with sugars and more soluble solids, creating a coffee that is heavy in body, sweet, smooth and complex. Naturally processed coffees tend to be fruity and wine-like, but can be more vulnerable to tainting by ferment flavours.
Natural processing is most often used in countries with scarce rainfall and prolonged sunshine, so that the coffee can be properly dried.
Washed or wet process
Wet processing is a relatively new method where the fruit gets stripped from the coffee bean within 12 hours of picking. The skin and pulp are removed by being quickly fermented, and washed off by pressing the fruit through a screen immersed in water.
The coffee beans are then sun-dried on patios or raised drying beds, sometimes followed by machine drying to further bring down the moisture content. Kiln drying may be used in overly humid climates where the beans are susceptible to rotting.
The wet process creates lighter bodied coffees that are brighter, cleaner and fruitier, sometimes with more delicate, floral, tea-like characteristics. It is often used to showcase high grown flavor and acidity.
A beautiful example is our Single Origin Colombia La Jacoba Microlot 1 – a sweet and juicy filter roasted coffee with orange and vanilla aromas, and notes of mandarin on the palate.
Semi-washed or pulped natural/dry process
An intermediate between wet and dry processing, the skin is washed off, but the pulp is allowed to dry on the bean over 24 to 48 hours.
The coffee ends up with characteristics of both methods, retaining some of the acidity of the wet process but is usually sweeter, with some of the body of dry processed coffee.
This type of processing can only occur in regions where the humidity is low and the coffee fruit can be dried rapidly without fermenting.
While some countries are restricted in processing methods by climate, others have more flexibility and thus more variation in the coffee they produce.
There are a number of other processing methods and experimentations with processing going on all across the World and we roast coffees highlighting all these methods over time. That’s the exciting part!
The next post will look beyond processing to examine the generalized flavor profiles of coffee from different regions.