While the world may seem chaotic right now, at least you can control one thing – your morning cup of home-brewed coffee! Luckily for us, scientists have broken down exactly which groups of chemicals have the biggest influence on flavour in coffee. And it’s as easy as remembering “A B C D E”.
A is for acid
Roasted coffee has at least nine organic acids in it. A group of compounds called chlorogenic acids are the most prevalent and are generally quite bitter. But there are also other acids that each contribute their own versions of what we might call “sourness”. For example, citric acid contributes a lemony-type sourness. Malic acid contributes flavours reminiscent of tart green apples; while acetic acid is essentially vinegar.
For coffee lovers who hate “sour” or “fruity” coffee, the bad news is that organic acids are highly soluble and dissolve very quickly, so you can’t really avoid them in your cup. The good news is that you can make them less noticeable by extracting other flavours, balancing out the more undesirable flavours.
B is for baked bread
Don’t you love the smell of freshly baked bread? Or perhaps pan-roasted almonds? These aromas come from a reaction called the Maillard reaction. In coffee, the Maillard reaction contributes savoury/umami flavours and aromas akin to fresh bread or roasted nuts. Like organic acids, Maillard compounds dissolve quite easily and often contribute to a fuller, richer mouthfeel.
If one of your common complaints is that your daily coffee tastes a little sour or savoury, it probably means that you’re only managing to dissolve flavour groups A and B. To solve this, you’re going to need more – not more coffee grounds, but rather more time, more temperature, or more turbulence (read: stirring). If you have a grinder, you can also try grinding your coffee finer. The more of these elements you can introduce, the more energy your brew water has to extract those trickier, less soluble compounds. Compounds like…
It’s the sweetness that (almost) everybody loves in their morning cuppa. These compounds are formed during the roast process as the natural sugars in the bean are heated. The trouble with some of these caramels is that they’re tricky to dissolve. More heat, more time, or a finer grind are all ways to extract more caramels into your cup, but you have to be careful. Those same things can also increase the bitterness if pushed too far. Which leads us finally to…
D is for degradation compounds
Strecker degradation compounds are largely responsible for bitter and smoky flavours – like those you might find in a peated whisky. Traditionally, they are also associated with the idea of a “strong cup of coffee.” The good news for those who love a strong, bitter cuppa is that you don’t need more coffee to make it taste “strong”. Instead, use a lower dose, but just brew for longer, with hotter water and with more stirring. Doing this will bring out more bitterness without needing to use more coffee. A win for the household budget.
For the rest of us, though, these flavours are unpleasant and are associated with “burnt coffee”. Luckily these degradation compounds don’t dissolve easily and you can avoid them almost entirely if you brew your coffee for a shorter time or use slightly cooler brew water.
Not all coffees are equal. Some are naturally sweeter and may taste of chocolate, rainbows and unicorns; while others are roasted to ash. To find coffees you enjoy, you may have to venture beyond just one brand. And be sure to check the roast date on the bag before you buy!