Scientists have worked out how to make the perfect cup of coffee

Most people drink coffee in the morning to function. It’s a world wide thing. And for some reason, some coffee just tastes so much better than others – but why is that? Well, if you’re wondering how to make that perfect brew every time, science has your back. New research has revealed what type of roast makes for the perfect cup of coffee (Picture: Getty)

In a new study, published in the journal Scientific Reports, a team of researchers created a series of lab tests to identify the blend of factors to make a perfect cup of coffee which balances flavour and zing to their brew. But it doesn’t seem to be good news for those who love a dark roast (Picture: Getty)

Dr Zachary Lindsey, an assistant professor of physics at Georgia’s Berry College said: ‘Over 20 years ago, I heard a barista claim that dark roasts have more caffeine, but a decade later, I was exposed to the contrasting idea that light roasts were the king of caffeine. Yet, I couldn’t find any convincing data. It wasn't until I picked up coffee roasting as a hobby in 2022 that I started to see the missing pieces of the puzzle. Luckily, two passionate undergraduate students on my research team were also intrigued by this mystery, and we got to work’ (Picture: Getty)

Dr. Lindsey and his team analysed the relationship between coffee beans’ chemical and physical attributes through various roasting and brewing situations. Their trial focused on only natural and washed processed Ethiopian beans, with researchers examining five varieties of roasts across brew times of one, two, and ten minutes using a machine with a 15:1 water-to-coffee ratio (Picture: Getty)

The researchers then used three techniques to analyse the caffeine content and extraction yield. To measure compounds like caffeine, chlorogenic acids, and other soluble compounds in the brewed coffee, the researchers used high-performance liquid chromatography (HPLC). Then, they used refractometry to see how much soluble material is dissolved from the coffee grounds. Finally, they used scanning electron microscopy (SEM) to observe the surface of the coffee beans and grounds. This helped them to examine the grain size and porosity (Picture: Getty)

And the results were in. The team suggests that, if you’re looking for a much needed energy boost, a medium roast blend provides you with the most caffeine per cup. But that's not all you need for a good cup of coffee. In a different, unrelated study, researchers revealed that for a cup of coffee, you’d want to go with reasonably hard water (Picture: Getty)

According to Dr Christopher Hendon, chemist at the University of Bath, sodium-rich water – like what is produced from water softeners – didn’t release the flavour’s full potential. The study showed that while high bicarbonate levels were bad for flavour, high magnesium ion levels were found to increase the extraction of coffee into water. So now you know how to make a perfect cup of joe. Don’t forget to grind your coffee into finely to increase the surface area of the beans, which will allow for more flavour to be extracted into the water (Picture: Getty)