One of my goals with Danelaw is to demystify specialty coffee, so I want to give you some more detail about one of the most common processes used in the coffees I source. Washed coffee sounds simple enough - just coffee that’s been washed right? But the details can be quite distinctive and it all contributes to how the coffee tastes.

Coffee grows as a fruit - a berry if you like (technically a drupe I think, like an nectarine) with the seed in the middle. This is the “bean” we want to get out. Outside the seed are several layers of protective membranes and coverings as well as plenty of fruit - pulp and mucilage. Keeping with our nectarine example, the pulp is the bit you eat that dribbles down your chin, the mucilage is the sticky bit that sticks to the stone that you can’t get off that means you can’t put the stone in your car’s cupholder.

The pulp and skin is removed by passing it through a machine that’s part mangle, part cheese grater. The pulp and skin go one way, the bean and mucilage go the other way.

Then comes the task of removing that mucilage, and this process generates lots of the flavour.

It CAN be done mechanically, but this tends to leave a less complex and more basic flavour.

What happens with most of my favourite washed coffees is that they will go into a big tiled bathtub with some water and the ambient microbes start to digest the mucilage. These tend to be yeasts and bacteria living symbiotically, much like a sourdough starter. Once these have acted on the coffee, usually about 12-24 hours depending on the temperature, the coffee will then be washed (hence the name) by flushing it down narrow channels with little blocks in the floor, which cause turbulence that effectively knocks the loose mucilage off.

Once all the mucilage has been removed, the coffee then needs to dry down to about 12% moisture for export. This can be done in massive drying machines that work like a 5 storey tumble dryer, or alternatively sun dried.

Drying can be done on raised beds, where air can circulate all around the coffee, or it can be done on a patio. Whichever method is used, it’s important to keep moving the coffee, turning it to ensure even drying and not allowing mould to develop.

Once dry, the coffee can be sorted, the final protective layer around the bean can be removed and it can be bagged and shipped for export.

I really like washed coffees - they tend to produce sweet, fruity cups of coffee, that are predictable and balanced. There are limitations though - they’re often more expensive to produce than other styles of coffee, and all that mucilage-rich waste water has to be treated before it is released to groundwater too.

In areas where water is scarce, they’re difficult to produce and climate change is making it difficult to predict when it might rain. If you are sun drying on a patio and it rains, it makes it harder to get your coffee dry enough quickly enough without it becoming tainted.

Correct as of February 2023, the following washed coffees are available on the website:

Colombia Planadas Selección

Honduras Mauro Rodriguez Parainema

Honduras Rosely Hernandez

Rwanda Rugali Washed

You also might want to try 3 of these in a taster box too.