The processing of coffee cherries into green coffee beans is the most significant contributory factor to flavour and cup profile. Cherries are either wet or dry processed and in some instances semi-washed – a hybrid of the two methods. The dry process is also known as the natural method and produces ‘unwashed’ or ‘natural’ coffee. It is the oldest method of processing coffee in the world and produces a coffee that is heavy in body, sweet, smooth, and complex.
The dry process is often used in countries where rainfall is scarce and long periods of sunshine are available to dry the coffee properly. It is not practical in very rainy regions, where the humidity of the atmosphere is too high or where it rains frequently during harvesting. It is critical that the drying process is carefully managed as a coffee that has been overdried will become brittle and produce too many broken beans during hulling while a coffee that has not been dried sufficiently will be too moist and prone to rapid deterioration caused by the attack of fungi and bacteria.
Before drying, the harvested cherries are usually sorted and cleaned, to separate the unripe, overripe and damaged cherries and to remove dirt, soil, twigs and leaves. This can be done by ‘winnowing’ where a large sieve is used to remove any unwanted materials. Alternatively the ripe cherries can be isolated in washing channels close to the drying areas; any defective green beans will float to the surface and be removed.
The coffee cherries are then spread out in the sun to dry – either on large concrete or brick patios or on matting raised to waist height on trestles. As the cherries dry, they are raked or turned by hand to ensure even drying and prevent mildew. It may take up to four weeks before the cherries are dried to the optimum moisture content, depending on the weather conditions.
The dried cherries are then stored in bulk in special silos until they are sent to the mill where hulling, sorting, grading and bagging take place. All the outer layers of the dried cherry are removed in one step by the hulling machine before the green coffee beans are bagged and sold.
The dry method is used for about 90% of the Arabica coffee produced in Brazil, most of the coffees produced in Ethiopia, Haiti and Paraguay, as well as for some Arabicas produced in India and Ecuador. Almost all Robustas are processed by this method.
Because “Unwashed” or “natural” coffees are dried while still contained within the fruit the coffee produced has a fuller body and, above all, a phenomenally juicy berry flavour. The challenge with naturals is that unripe and over-dry coffees are harder to sort out, and as such some unwashed coffees are associated with a range of inconsistencies–unripe, nutty-tasting beans called “quakers” are the most common–unless the mill or the roaster, or both, take great care to ensure consistent quality. Many within the industry hail a good quality natural, but some prefer washed coffee for its cleaner, smoother profile. We asked our traders for their view.
Trader Phil Searle, who’s recently joined the industry, enjoys a natural but feels they are not a morning coffee: “It’s better for the afternoon. It’s great to get some really lovely fruity flavours. They're a bit like a cider – you don’t want one in the winter!”
“I couldn’t have many cups of a natural – it really gives your tastebuds a run for your money!”
In terms of the market’s attitude towards it, Phil believes there is certainly more willingness to buy more naturals now in comparison to a few years ago, however the demand for washed coffee does still outstrip this.
Speaking with Jay Baxter, he related a recent ‘Let’s Cup’ event in our Selection Room:
“We cupped a natural Sumatran that just jumped off the cupping table. To see our customers' reaction as they cupped it was fantastic! Their comments included artificial bubble gum flavours; really sweet and fruity; strawberry bubblegum, chocolate orange, strawberry cheesecake.”
He also values the impact the new interest in naturals is having on the industry:
“It’s an acquired taste but really keeps the industry interesting. It’s funky and unusual and sometimes needs to be explained that that’s what it’s supposed to taste like! The older generation tends to dismiss it out of hand thinking it is fermented – we think it’s exciting – it’s making the coffee industry really interesting.”
“Origins are thinking more about how their coffee is being drunk at destination. They are happy to try different things that may appeal and are really opening up the options. What we’re really enjoying seeing is how growers and roasters are working together to trial naturals to achieve certain flavour profiles – it's making for a lot more collaboration. It lets them add value to their offering and makes more money for them, which is great.”
Simon Wakefield shares a slightly different sentiment on a natural coffee: “During my training in Papua New Guinea we learned that when coffees became too fruity it meant they were fermented. For me personally, a lot of the naturals are too close to this for comfort! It’s a coffee which I can manage half a cup of but no more – the really intense fruit flavours are too much to enjoy.”
And in terms of what it's doing for the market:
“It’s great what it's doing for the industry – growers and roasters working collaboratively and creating some really interesting naturals and semi-naturals. Do I want to drink them? Not really – but it’s important to know what makes a good natural – whether you personally like it or not.”