Fun-facts from the Roastery
It's not unusual when you visit us for a roastery tour or coffee cupping, to be treated to some intriguing coffee-based tales from the team. We asked our colleagues to share their favourite facts with you.
First Crack or Pop
Dr Eduarda Cristovam, Director of Coffee, Quality & Sustainability
Roasting coffee can be like making popcorn. The green coffee beans crack or pop and puff up when heat is applied. For a coffee roaster being able to hear that first crack point is important as it signals changes in the chemical reactions inside the beans that lead to flavour development and determines what to do with the heat applied. A little bit like when making pasta or rice and the recipe advises to turn the heat down to simmer after it reaches a hard boil.
In busy and loud roasteries hearing that first crack is not always easy. If roasters get it wrong, they might lower the heat too late and lose control of the roast; this often equals charred, tipped or poorly developed beans. If they lower the heat too soon, they might stall the roast and bake the coffee. So, roasters often use other cues (appearance and smell) to determine if the elusive moment is taking place.
To train our roasters to identify the first crack point no matter the noise we decided to block all sound coming from the coffee during roasting and ask our roasters to signal when they thought the first crack point was taking place. To make this happen we gave our roasters headphones while they were roasting coffee and we played Eminem on full blast through the headphones. These distractions forced the focus to move to smell development and changes to bean appearance.
Interestingly not everyone uses the same cues. Some rely on aroma only and are like bloodhounds. Others rely on the change to colour and the surface of the bean, and a few individuals touch the hot beans constantly to judge moisture content. After several failed attempts everyone got the hang of it and switched from using sound as the sensory cue to smell, appearance and a big dose of instinct to pinpoint that important first crack point. Better still some widened their vocabulary and the ability to sway to music while roasting coffee at the same time.
Hessian Sacks
Alan Beattie, Sustainability Analyst
The hessian sacks the coffee comes in get recycled into carpet backing or packaging for other goods. We also send hessian bags to a local play group in Glasgow.
Rest Day (or Year...)
Fergus Lamont, Junior Coffee Buyer
If you have a particularly intense session in the gym, you might find it takes you a few days until you’re back to your best or are back to “optimum performance”. The coffee plant, like us, is sometimes no different: when it has been a particularly fruitful year for a crop, a bit of recovery is sometimes required before it is back to its best. 'The biennial effect' is the name given to this very coffee phenomenon; whereby coffee crop yields may drop one year compared to the next on account of a physiological recovery of sorts. Brazil, as the world’s biggest Arabica producer, is a notable example of this phenomenon, illustrated here.
SOURCE: Rabbich, D, DRWakefield, Biennial Production in Brazil, 2022, [last accessed 17/05/2022 from https://drwakefield.com/news-and-views/biennial-production-in-brazil/#:~:text=Biennial%20production%20is%20where%20a,the%20fruiting%20cycle%20in%20coffee
Coffee Grounds
Alan Beattie, Sustainability Analyst
Used coffee grounds can be used to remove fleas from your pets! Fleas don’t like coffee and can be used as a natural treatment as an alternative to harsh chemical options. However, coffee grounds may be less effective so a vet should be consulted if this doesn’t work. Also, coffee grounds should only be used externally as they can be toxic for dogs to consume!
Also, you can use used rounds to neutralise odours in your fridge due to the nitrogen contained in them. Place a bowl of them in your fridge and you’ll no longer be blamed for keeping last night’s Chinese left-overs!
Coffee Chaff
Alan Beattie, Sustainability Analyst
Any of the chaff, or silver skin, that is discarded in the roasting process is pelletised and is sent off for anaerobic digestion for energy production.
You can also use coffee chaff for mulching. It adds helpful nutrients, the main component being nitrogen, to compound and mulch mixtures. Tomatoes respond particularly well to the addition of coffee bean chaff to the mulch mixture.
Coffee chaff is believed to have medicinal properties, including fighting obesity-related inflammation. Plus, it’s non-toxic and thought to have antioxidant properties! Coffee chaff on ice cream?! It isn’t known for its great taste but New Zealand coffee company Kōkako has put that last assertion to the test by creating sweet treats using this by-product.
And finally....
An unusual processing method from Indonesia
Fergus Lamont, Junior Coffee Buyer
Goats Feet
Sumatra, as the world’s fourth-largest coffee producer, polarises the market with its funky flavours, full bodies and herbal tones. But what makes Sumatran coffee so distinctive, and unique? Giling Basah, in Indonesian, translates as “wet grinding”, and is the term given to the idiosyncratic process native to the island, whereby coffee beans are hulled far “wetter” than usual.
Hulling is the process of coffee production when the paper-like layer that surrounds the coffee bean is removed. Typically, beans are only ever hulled after being dried to around 12% moisture content. In Sumatra, however, beans are often hulled at up to 35% moisture content, still bloated with water. Although not a complete science, it is thought that this disruption to the drying process contributes to this enigmatic end product by way of inconsistent drying and subsequent ambience.
This process can take its toll on the beans, with cracks or splits appearing as a result, often creating a peculiar hoof- or goat’s foot- like appearance…