There has been a long standing difference between coffee drinkers: How do I store my coffee properly? On a shelf? In a bag? In the refrigerator? While many people have their own personal preference, a new study suggests that there is an added benefit to this practice in more flavorful coffee.
In the grand search for a better tasting cup of coffee, people have tried all sorts of different things in order to coax more flavor out of the beans. People have even added eggshell, salt, butter, and many other things to their coffee grounds in order to brew up a better flavor. This new study shows that a simple step will offer up more flavor than any of the trends that have passed through your coffee machines over the years.
Cold coffee beans
Scientists from the University of Bath collaborated with a local café in studying the various effects of grinding coffee beans at different temperatures. The study utilized various temperatures, from room temperature all the way down to a frigid -196°C. As the research, now published in Scientific Reports, points out, the coffee brewing process is more efficient and we get more “bang for our buck” when grinding cold coffee beans. Thus, during the brewing process, one gets more flavor from brewing the same amount of coffee.
Brewing coffee is a chemical process, much like any other act in the kitchen. Through brewing coffee, we are attempting to draw out as many organic molecules from the roasted bean, which has been ground into tiny bits before brewing.
How the coffee turns out depends on many different factors. Some of these factors include water chemistry, the “accessible” surface area of the coffee grounds, and now, according to this study, the temperature of the bean when it was ground. As the scientists pointed out, small and uniform coffee grounds allow for more surface area to come into contact with the water, which in turn allows for better extraction of the beans’ flavor compounds. This, consequently, allows for more coffee to be brewed per bean, and, thus, more flavor.
More bang for your buck
“What you’re looking for is a grind that has the smallest difference between the smallest and largest particle,” says Christopher Hendon, a chemistry Ph. D. student at the University of Bath and one of the researchers involved in the study. “If you have small grinds you can push flavor extraction upwards. We found that chilling the beans tightens up this process and can give higher extractions with less variance in the flavor – so you would have to brew it for less time or could get more coffee from the same beans.”
Hendon also said that this process changes the taste of coffee because “subtle changes in particle size distributions make a huge difference in the rate of extraction.” Additionally, the research has shown that in order to achieve more consistent grinds, the temperature of the bean needs to be constant. Since cooler temperatures maximize the surface area, this allows for more of the coffee bean to be used.
How this will affect the coffee industry has yet to be seen, but study co-author and café owner Maxwell Colonna-Dashwood believes that it will indeed. “All of this will impact on how we prepare coffee in the industry, I bet we will see the impact of this paper in coffee competitions around the globe, but also in the research and development of new grinding technology for the market place,” said Colonna-Dashwood.
