Today, The New York Times hooked countless coffee aficionados (myself included) with a clickbait enticingly called "You Want Tastier Coffee? Freeze Beans, Then Grind." The article references a new study published in Scientific Reports that looked at grinding coffee beans at different temperatures to see how they turned out. They found that colder beans produce smaller, more consistently sized particles when you push them through a coffee grinder, and as a result, you get more flavor from less product. Intriguing? Yes. Should we all run to our freezers? Probably not.
"Cold is not recommended for preserving the integrity of beans," says Jeremy Lyman, co-founder of Birch Coffee. Coffee beans in the study were placed into either liquid nitrogen, a tub of dry ice, the freezer, or on the counter top before roasting. However, those beans were only kept cold for two hours in the study. When you're storing your beans in the freezer, opening and closing the door multiple times exposes them to more humidity as they defrost and refreeze. This cycle breaks down the beans faster, leaving you with stale coffee.
"Something warmer would be mushier and therefore harder to cut cleanly than something that is cooler and therefore firmer," says Jim Munson, President and CEO of The Brooklyn Roasting Company and previous member of the National Coffee Association Information & Education Committee. "That said, they've got it wrong when it comes to particle size and the resulting brewed coffee flavor." He goes on to explain that the article suggests that given the same extraction temperature, finer particles result in more sour flavors than coarser particles do, which they claim would be more bitter. "I believe the consensus in the industry and in general would be exactly the opposite!"
But if you really want to test the study's claims for yourself, chill only the beans you're about to grind and do it immediately before brewing. More simply put: "If you're the type of person who decants your wine and lets it sit for 45 minutes, or warms up your bathrobe in the dryer before putting it on, then you should probably freeze your coffee beans before you grind them," says Munson. Otherwise, just stick to storing your beans in a cool, dark place, far from your freezer, or buying your cup from a reputable local shop.