Last week I spent a very enjoyable morning learning all about the sourcing, roasting and brewing of coffee at a session put on by Clerkenwell coffee house Workshop (previously St Ali). As well as putting on a mighty lovely all-day dining spread, Workshop also take their coffee very seriously, with an in-house roaster at the rear of the shop and a brisk takeaway trade.
Our host and coffee manager, Tim, started by telling us a load of fascinating stuff about coffee that I never knew. For example, did you know that the skins of the coffee cherries (the beans are the inner ‘pip’ of this fruit) are caffeinated because it’s a natural insect repellant, and the dried skins can be brewed into a tea called cascara? And that’s just the start – we discussed the different varieties of coffee and the effect that altitude, location, processing and volume have on its quality and flavour.
Tim then explained how they go about sourcing and selecting coffee for Workshop – often they only get a 100g sample which they have to carefully roast and brew in order to decide whether to spend £60,000 on an order. Workshop ensure that they pay a fair price for their premium beans and try to have as open and transparent a relationship with their importers and farmers as possible.
We then saw the roasting process: raw beans are tipped into the roaster and a laptop displays the ‘recipe’ that each variety is to be roasted to. The temperature is painstakingly monitored and data-entered each minute that they roast to ensure a completely consistent result – a variation of just two degrees means the batch is no good. Workshop roast their beans very lightly to just bring out the subtle natural flavours – a more typical coffee chain might over-roast to mask poorer quality beans.
After 14 minutes of roasting, the beans are cooled and then bagged. They have to rest for a week to release any trapped carbon dioxide that can make the coffee bitter. Workshop’s head roaster Richard spends two days roasting approximately 300kg of coffee per week, which is sold via drinks in their two London locations, and also a small proportion as wholesale and retail beans.
Finally, we experienced a sample ‘cupping’ session. Tim and Richard do this every week to ensure consistency in the newly roasted beans, and also when tasting new additions to decide how they should be roasted and brewed.
The cupping session is almost ritualistic, like a Japanese tea ceremony, but this is to make sure the coffee is tasted with as few variables as possible. Beans measured into precise 12 grams, ground and added to bowls; kettle boiled and cooled; water poured; coffee stirred; wait for brewing; skim the top and taste a teaspoonful with a slurp.
We finished with a lovely brunch in Workshop’s restaurant, washed down with yet more coffee. This was a ‘beta’ session to see if the concept worked, which I think it most certainly did. I left with an even greater understanding and appreciation of coffee, along with a long list of wonderful facts to bore people with – I didn’t even share half of what I learned here. Tim plans to schedule in more sessions for the public to book onto soon: keep an eye on their Twitter for news.