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Fermentation ‘essential’ for Colombian coffee

When it comes to coffee, there are a series of factors that affect its taste, aroma and all other qualities that make coffee what it is. 

However, writing in Barista Magazine, the Colombian Coffee Hub has branded fermentation as an "essential variable" in producing high-quality Colombian varieties.

According to the organisation, mildness is one of the key traits of Colombian coffee – therefore one which consumers with a sharp palate will be looking for. It believes that this is due in part to the delicate processing of the beans – as well as, of course, the climate in which the coffee was grown, the harvesting methods and the origin of the Arabica bean.

When coffee cherries are harvested, they need to be processed, for which there are three definitive procedures – dry, semi-wet or wet, and fermentation is part and parcel of the latter.

For dry processing (common in Robusta-producing regions), the beans are picked and left out to dry in the sun, without being depulped. For semi-washed beans, the cherries are depulped before being left to dry.

However, it is the beneficio method – the Spanish name given to the post-harvest wet-processing stage – that the Hub believes plays a crucial role in Colombian beans resulting in such a beautiful, mild beverage for end consumers.

In itself, the wet-processing method comprises several stages – that is, depulping, fermenting and washing – that are repeated to ensure that the procedure is done sufficiently meticulously. 

It can take anywhere between 12 and 28 hours, depending on various compounding factors such as temperature (the higher the temperature, the faster the process), the quantity of coffee being fermented, the maturity of the cherries (rather, how long they have been left on the crop before being harvested) and – of course – the amount of mucilage there is to break down.

This is what the fermentation stage is for – to break down the mucilage that clings to the outside of the beans. Combine this process with ones that are a quality Arabica variety, and the resulting coffee will be mild and sweet. A dry-processed Robusta bean, on the other hand, is likely to taste heavier and more bitter.

As would naturally follow with more component parts, wet processing is more time-consuming, requires more resources, and therefore adds the most value to the final product. However, opinion remains divided over which produces the nicest varieties of coffee. 'Naturals' – as dry-processed varieties have come to be known – are becoming increasingly popular, especially with younger generations of coffee lovers.

While DR Wakefield's managing director Simon Wakefield is not as keen on naturals, trader Phil Searle is indeed a fan, saying: "It's great to get some really lovely fruity flavours.

"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."