20 - 23 April 2023 / The Truman Brewery
24 March 2014
24 March: The Craft of Roasting Speciality Coffee by Hand
Interview with Oli Brown, Quality Manager, Union Hand-Roasted Coffee - Without the skill of our roasters and the years of experience which we have gained, we would not be able to get the right flavours and taste sensations. The ability to continually reproduce and hit the correct profile...
Interview with Oli Brown, Quality Manager, Union Hand-Roasted Coffee
Without the skill of our roasters and the years of experience which we have gained, we would not be able to get the right flavours and taste sensations. The ability to continually reproduce and hit the correct profile batch after batch is key to consistency in our blends, whilst having a solid understanding of the different processes, origins, densities, varietals is vital to the success of roasting all our single origins coffees at the Roastery. We work hard to maintain our artisanal craft approach to roasting coffee by hand, not computer.
The flavour and taste of all coffee beans are defined by the growing conditions, processing and the skill of the pickers, farmers, Co-ops and mills. But we as the Roaster have our own crucial part to play in the journey of the coffee bean from the farm to the consumer.  It’s we who put our own stamp on the process and where, if care is not taken we can squander all the hard work. Alternatively it’s where our skill can bring out the best that the beans can possibly offer and make the consumer have that ‘coffee moment’. 
How roasting can affect flavour and taste
The skill of Roasting Coffee is so much more than hitting a specific shade or colour of bean. 
It sounds simple, but the way in which we apply heat and air will drastically change the flavour and taste sensations in the coffee beans. It’s up to myself and more specifically our Roasters to make sure we’re getting it right every time.   
No one roast fits all.  
At Union we work with many different Single Origin coffees and each will require its own roast profile.
The Profile of Coffee
The different stages of the roast make up what is known as ‘the profile’. We use Cropster to log technical data about the roast. Cropster literally draws the shape of the roast profile, showing us roast temperature over time to give us a visual representation of what’s going on in the drum.  It’s great because we can see not just temperature and time, but the rate of the temperature rise. It allows us to refer back to previous roasts of the same beans, and replicate or improve the results.
There will be variances in profiles for each coffee, and our roasters expertise allows them to choose the correct profile for each bean.
Other factors impact the roast profile as well.
Process vs profile
Any given beans can be processed in different ways for varying results. For example in Costa Rica it is common to process the same harvest of beans via a number of methods:  
the natural process: left with its cherry still on to dry under the sun on raised African beds
the Honey process: cherry removed but left with most of its mucilage (the layer of sugar around the bean) still in place
the washed process: all of the sugar layer washed off and dry on raised beds thus giving a very clean and pure flavour of the coffee bean.  
We design our specific roast profiles to make the most of the processes and thereby highlight these different flavours, for example bringing out the wilds strawberry fruits of a natural coffee, the jammy redcurrant, sugar cane and brown sugars of the honey process, or the vanilla, chocolate and caramel and fudge of the fully washed process coffees.  
Timing matters
A short roast with high temperature input and lots of air in the drum until first crack, might bring out more of the fruit flavours and acidity. More heat input in stage two can bring out more body and more of the sweetness.  A longer roast with more even heat application throughout stages one and two will mute the fruit notes of a given coffee and give off darker bolder flavours like dark chocolate notes, treacle, chocolate brownie flavours and remain very sweet with little or no fruit but a long bold aftertaste. Perfect for milk based drinks. 
Origin and terroir
Origin is also important as it can give a guide to how a coffee might behave in the drum. Traditionally Roasters have approached coffee on solely on region-by-region or origin-by-origin basis. However as the speciality coffee industry has progressed and changed as part of the ‘third wave’, the regions have started to take less of a significance and roasters are now looking at aspects such as variety, process and altitude more often than just notes, and approaching the roast on these terms rather than specifically on a Country of Origin basis. 
Variety is another value to consider. Bourbon, Typica, Caturra and Catuai for example can take quite a lot of heat. Geisha, Euginodies and Mokka are more delicate and can lose their fruit flavour characteristics easily if over-roasted. 
Funnily enough the local ‘weather conditions’ in the roastery must also be taken into account when roasting coffee. On a cold day we know that a coffee might roast faster: hit the first colour change and first crack earlier. Or on a hot moist sunny day the roast might be slower as it takes longer for the moisture to be driven from the beans, which in turn affects the later stages of the profile and delays the different points of the profile.  
So there are a multitude of factors which can affect roast profile of a particular coffee and our roast team are presented with a massive challenge when approaching the daily production roasts.  
Whether we’re roasting for our online customers in our 10kg San Franciscan Roaster or dealing with a larger batch of Equinox on our 90kg Probat, every roast is approached with the same care and attention. All the coffees are roasted by hand, the artisanal way and with the roaster using his skills to get the utmost flavour and consistency from the beans.

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