Last updated March 22, 2018 at 12:18 pm
America has bad coffee, so thankfully a scientist is on the case to help them brew better.
There is no doubt Australia is the best coffee country in the world. We love the stuff, we take it seriously, and it’s notoriously hard for international brands to break into the market.
We’re loyal to our baristas – with names like Kyan and Philip and Kiara and Fiefy becoming our morning heroes. In other countries, cafes and coffee shops advertise the fact they have an Australian barista behind the counter.
Every year we spend well over $4 billion getting our fix.
Other countries, namely the US, struggle with coffee. They tried to give us Starbucks, which we sent back with its tail between its legs. Because it was bloody terrible.
So it’s not necessarily a surprise that US scientists have been working out how to create better cups of espresso. Now, they think they’ve unlocked the key to creating a consistent flavour profile between cups.
The secret of coffee
“One day you might have a good cup of coffee and the next day you might not. From a scientific perspective, it has always puzzled me why we couldn’t do the same thing twice,” says Christopher Hendon, aka “Dr Coffee” from the University of Oregon.
“My research looks at every variable that goes into making espresso coffee, from grinding and packing the ground coffee, to water pressure and mineral chemistry. If every single café in America were to implement the procedure, it would save the U.S. $300 million a year by reducing the amount of coffee beans used to make espresso, while improving reproducibility.”
Credit: Charlie Litchfield, University of Oregon
Already, Dr Coffee’s lab had found that the differences in water in different areas of the US played a big role in changing the flavour.
In some areas, “hard” water with a high amount of magnesium and calcium caused coffee to have a stronger flavour than “soft” water.
According to Dr Coffee, this is due to caffeine and other compounds sticking to magnesium during the brewing process. Hard water can also have high amounts of bicarbonate, which causes coffee to have a more bitter flavour.
Something that every self-respecting Aussie also already knew is that the freshness of the coffee beans can also impact how tasty a cup of coffee is. Freshly roasted coffee contains carbon dioxide and other compounds that easily evaporate.
When beans are stored, these volatile compounds escape the beans, resulting in a less flavourful cup of coffee when it comes to be brewed.
It’s all about the grind
Dr Coffee’s team have changed focus however, and instead looked at the process of grinding coffee beans.
While intuition suggests smaller particles means more surface area, which should result in consistently tasty espresso, the research found there is a critical point at which smaller isn’t better.
“There is a point in grinding coffee beans when you make too many small particles, which stick together and result in reduced extractions,” he said.
For this reason, Dr Coffee points to the type of grinder as having significant impact on the flavour of the resulting coffee.
The team also examined the brewing method itself.
When extracting the espresso, the water should come into contact with the coffee grounds equally.
In comparison, with an awful US-style drip-brew coffee pot, the water drips mainly through the centre of the grounds while the grounds on the outside have little contact with water.
To try to help his fellow Americans, Dr Coffee collaborated with baristas to develop a method by which they can achieve their desired flavour profile consistently, the results of which he is presenting at the American Chemical Society 255th National Meeting.
“By predetermining the coffee-to-water ratio, as well as the water pressure, the maximum extraction can be systematically determined,” he said before the presentation.
“The barista can then iteratively improve their espresso reproducibility, while reducing waste coffee mass.”
Is this the turning point for American coffee? The rest of the world hopes so.
