When I was growing up, my parents kept their cans of Maxwell House ground coffee in the freezer. This was in the Pre-Internet days, when you had to physically go to libraries to source quality information. Though they were coffee lovers, I don’t think it ever occurred to them to research the practice. Probably they were informed through word of mouth from someone they respected; that doing so prevented the grounds from oxidizing quickly. It does sound logical as freezers maintain freshness. Of course when I struck out on my own, I also stored my coffee in the freezer without giving it much thought. It’s amusing how we don’t begin analyzing the little nonsensical idiosyncrasies accumulated from our parents until we’re over 30.
Since that bygone era, research has surfaced to supplement the advice on most coffee labels, educating all who care on why they are to heed the label’s advice. The directions are simple: Store your coffee in some type of opaque, airtight container, and away from light, heat and moisture. All of which expedite corrosion, a definite flavor killer. Though the instructions are straightforward and science based, I am regularly amazed to find improperly stored coffee, and a subsequently lackluster cup of coffee in many, so-called, professional coffee houses.
That being said, for all those who staunchly refused to remove their beans from the freezer…you are now on the right side of history, as current research is pointing back to the freezer.
Apparently, when beans are ground at frigid temperatures, the particle size is more uniform, which leads to thorough and consistent flavor extraction.
Why this matters: Coffee blends are comprised of a variety of beans with distinct flavor profiles, formulated and mixed precisely by highly skilled master roasters. The end result a delicious and balanced cup of coffee. If particular beans are over or under extracted, the flavor will suffer.
However, before you begin neurotically freezing your beans, take a good look at your coffee grinder, and measure the temperature in your storage cabinet. If you don’t have a good quality burr grinder, (why this matters?) it’s likely your particle size is not going to be purely uniform anyway.
When I brew beans at home that have been taken from a sealed container in the freezer, my coffee tastes better than when taken from a sealed container in the cabinet. I had incorrectly assumed my storage shelf was cool and dry, a rookie mistake I know. In reality, it was receiving way too much heat from the sun and range during the day. So, FYI, beans should be stored at 68-77 F or 20-25 C.
Of course, the best way to enjoy the coffee at its peak is to buy freshly roasted whole beans, and then grind them on demand.
Uman, E. et al. The effect of bean origin and temperature on grinding roasted coffee. Sci. Rep. 6, 24483; doi: 10.1038/srep24483 (2016).