Here Comes The Science Bit

In winning the 2017 World Barista Championship, Dale Harris made use of the latest technology to analyse aromatics. Here he explains the process

- Dale Harris

People are drawn to speciality coffee for many reasons: the culture, the people, the brands, the sense of belonging. The industry hopes to attract customers by promising that coffee can taste different. Actually, it promises more: that coffee can taste much better than people expect and that it has a diversity of flavours beyond those offered by almost all other products.

At some point, most people have been entranced by the complex flavours and aromas of coffee. They may not be able to explain why this is, but there are solid, scientific reasons.

When simple amino acids – the fuel cells built by biological actions in plants and animals – are exposed to a certain level of heat for the right amount of time, they are transformed into a complex range of aromatic compounds. This is known as the Maillard reaction and is what happens when coffee is roasted, bread baked, steak grilled and onions sweated. Humans respond to these complex webs of aromas.

The process is a series of reactions, and each part of this sequence can produce different compounds dependent on the substances present at that stage, precise temperature, pH and other factors. The complexity of green coffee contributes to this diversity: it contains different starches, sugars and proteins dependent on the mineral content of the soil in which it was grown, the length and consistency of its maturation, and even the way the seed was released from the cherry and dried.