Don't Freeze Coffee, and Five Other Tips for Treating Beans

It’s a triumph to buy great coffee, but thanks to oxygen, what happens once the beans reach home can reduce a premiere microroast to nothing better than a commodity cup. Below, coffee consultant and Cup of Excellence Managing Director Sherri Johns offers advice on how to properly source and handle beans, plus ways to repurpose them once stale.

"When beans are roasted, they become porous—like little sponges—so it’s important to store them away from heat, light, moisture, and air." -Johns

1) Coffee has more enemies than just poorly-trained baristas, jokes Johns. "When beans are roasted, they become porous—like little sponges—so it’s important to store them away from heat, light, moisture, and air." That includes your refrigerator, she adds. "Coffee will pick up the onions in the bottom, the butter on the third shelf." Don’t put your coffee in the freezer either—the moisture molecules in the coffee beans will freeze and expand, causing tiny hairline fractures in the beans' structure. The air in the fractures can become stale and result in a vastly disappointing cup later.

2) Choose a clean, non-porous, airtight container. Glass works well if kept away from light and heat, says Johns, while porous plastic will absorb the oils from coffee as it ages and taint the next batch with the stale oil from the last one. Metal works fine, if it’s kept away from heat and moisture.

3) Buy fresh coffee. Retailers, in interest of keeping the product on the shelf as long as possible, will pick "best by" dates far outside ideal conditions. If possible, avoid the grocery store altogether and purchase beans from a quality local micro-roaster. But either way, look for the coffee’s birth date (roast date), not its death date (best by date).

... coffee, once roasted, is fresh for seven to 10 days maximum.

4) Buy small quantities—as much as you can drink in a week. Because coffee, once roasted, is fresh for seven to 10 days maximum. Depending on the origin country or the elevation, beans will have different densities, and various cultivars of coffea arabica come in different sizes. (Bourbon beans are small and tight, while Pacamara beans are large and porous.) So, all will roast differently. Once roasted, though, according to Johns, "they are on an equal playing field, and need to be respected."

5) Just because coffee still smells like coffee, it’s not necessarily fresh. Per Johns, "Even though coffee may still smell great after a month, the truth is that immediately after roasting it starts deteriorating. Would you buy a baguette on Monday and service it Friday? Of course not. Would you store that baguette in the freezer and expect it to taste just as great as fresh?" There are means to keep oxygen away from coffee by using nitrogen, she adds, but really, it’s best to respect the innate life cycle of the beautiful brown cherries and use quickly.

6) Use stale coffee creatively. "Worms love it, snails hate it. Roses love it and old grounds work nicely in the garden—make a ring around plants and it keeps the snails away. Night crawlers thrive on it when mixed with soil. Or, take grounds and blend with sea salt and a nice lavender or other gently scented oil for a coffee scrub."