I’ve got a dirty little secret: for more than five years I have been freezing whole-bean coffee. I say this knowing full well that a thousand roasters and coffee purists from around the world may rain judgement upon me, but if done right, freezing extends the freshness and shelf life of your coffee for months. The key advantages of freezing are that you’ll save money by buying larger amounts of coffee at a time (freezing the excess), you’ll reduce waste, and avoid the inevitable declining enjoyment due to staling beans.
The dos and don’ts of freezing coffee:
- Use only fresh, whole beans i.e. the closer to the roast date the better. There’s little point in freezing old beans.
- Ensure the container / bag is airtight. This is crucial as moisture will ruin your beans if the container isn’t perfectly sealed. I transfer my beans to ziplock bags, remove as much air as possible and very carefully seal the bag before placing at the back of my freezer. Ziplock bags can be carefully washed and reused.
- Don’t freeze coffee beans in the bag you bought them in, even if it’s unopened. Coffee bags are typically not designed for freezer storage.
- Freeze in small amounts. I freeze in 125 gram batches, which last me around a week each.
- Only remove the bag from the freezer once. Some proponents for freezing suggest that refreezing beans after taking them out is ok, but it’s not something I do. Freezing in smaller batches should make refreezing unnecessary.
- Allow the beans to warm up to room temperature before opening. Opening the bag right from the freezer can cause condensation inside the bag, introducing moisture to the beans.
I got on the frozen bean trip after a mate sent me a link to a Home Barista article (Coffee: To Freeze or Not to Freeze) in which Ken Fox and Jim Schulman pretty thoroughly explored the idea. 64 espresso shots from unfrozen and frozen (4 and 8 weeks) coffee beans, assessed for crema, flavor, aroma and preference.
Here’s a couple of takeaways from the article:
“Two months is safe: Freshly roasted coffee that is immediately frozen after roasting in a near airtight container in a very cold freezer, can be kept undisturbed in the freezer for at least 2 months and be expected to produce espressos that are not obviously inferior to those made from fresh coffee that has never been frozen.”
“Freezing does not accelerate staling after defrosting: At least over a period of time extending to about 8 days after roasting, using the roasting and freezing procedure used here, there was no evidence that previously frozen coffee deteriorates more quickly after defrosting than does coffee that has never been frozen.”
They carried out a second test, addressing some criticisms of the first experiment and again the results gave freezing the thumbs up:
“Freezing remains a viable method for the preservation of coffee roasted for espresso, for a period of at least 4 months.”
“It seems unlikely that freezing and defrosting has no effect at all on roasted coffee; but I think, given these results, it is impossible to claim that the effect of freezing is larger or more harmful than any of the other things we do with fresh roasted coffee in the first week of its life.”
The results were certainly convincing enough for me to at least try freezing my excess roasted beans and five years later, I’ve never looked back. I’ll wager that most folks who frown on freezing coffee beans have never done it. There is at least enough supporting evidence to warrant trying it. I’ve provided several additional sources below and I hope it’s enough to convince you to try your own freezer experiments.
Kenneth Davids is editor, chief writer and co-founder of Coffee Review http://www.coffeereview.com. He travels the world educating folks on coffee sourcing, evaluation and communication. Kenneth is also Editor-in-Chief to the Oxford University Press Companion to Coffee due to be published in 2019.
In his three books, Kenneth David recommends freezing coffee beans for longer storage. He is pragmatic about it and you’ll see below that while he believes freezing to be very effective, he recommends it only if necessary.
Freeze coffee that you can’t consume within a few days after roasting. Whether or not it’s a good idea to freeze whole-bean coffee is one of those peculiar controversies that run unresolved through the rhetoric of the coffee world. Two of the country’s leading technical experts on coffee roasting are diametrically opposed on this issue, one touting the freezer as the perfect place to preserve roasted whole-bean coffee and the other excoriating freezers as the best way to destroy the structural integrity of the bean and its capacity to protect flavor.
I would argue that freezing whole coffee beans while they’re fresh is silly, but if you absolutely have to keep your roasted beans around for more than three or four days before brewing, I find the freezer helps considerably more than it hurts. Put the beans in a sound zip-tight freezer bag and squeeze as much air as possible out of the bag before sealing it. Remove only as many beans as you intend to consume for the day and immediately reseal the bag and return it to the freezer. Allow the beans to thaw before grinding and brewing.
Home Coffee Roasting
“If, however, you shop for coffee less frequently than the righteous coffee lover truly ought to, and if you keep your whole-bean coffee around for more than a week before you consume it, place it in carefully sealed freezer bags in the deepest recesses of a good freezer as soon as you get it home.”
Espresso: Ultimate Coffee
“Freezing, however, is an excellent way to preserve whole-bean coffee if you do not intend to drink it within a week.”
Coffee: A Guide to Buying, Brewing, and Enjoying
It’s with good reason that Eileen P. Kenny, in a 2015 post on Sprudge.com, called Rao “One Of The World’s Most Influential Coffee Thinkers.” Scott is the author of several excellent books on coffee: The Professional Barista’s Handbook, Everything But Espresso, Espresso Extraction, and The Coffee Roaster’s Companion (my personal favourite). Here’s what he had to say about freezing beans in his book, The Coffee Roaster’s Companion:
“Although it still has its skeptics, freezing coffee has proven itself to be very effective for long-term coffee storage. Freezing decreases oxidation rates by more than 90% and slows the movement of volatiles.”
“There is no need to worry about the moisture in freshly roasted coffee actually freezing, as it is bound to the coffee matrix, which makes in nonfreezable.”
Rao references the book, Coffee Technology (Sivetz and Desrosier), and the following study:
Interactions of water with roasted and ground coffee in the wetting process investigated by a combination of physical determinations.
Journal of Agricultural and Food Chemistry (2007)
Mateus M.L., Rouvet M., Gumy J.C., Liardon R.
Michael Sivetz and Norman W. Desrosier
Sivetz and Desrosier advocated for freezing coffee beans in the book, Coffee Technology, way back in 1979. In the book they claim that freezing coffee beans leads to reductions in water reactivity, rate of oxidation, and aromatic volatility.
“freezing coffee to -10 F or -20 C, as in the household freezer, is a very effective way for extending the freshness of coffee aromatics for several reasons.”
Avi Pub Co (January 1979)
Sivetz went so far as to file for a patent for a method of keeping roasted coffee beans fresh, which included freezing.
Roast coffee bean freshness is maintained by storing just roasted beans in a sealed container having much less than 1.0% oxygen therein. Storage of roasted coffee at very low temperatures (less than −40 degrees F. (−40 degrees C.)) also preserves the freshness of the coffee. The combination of low oxygen and low temperature storage provides the freshly roasted coffee taste and a long shelf life for that preserved taste.
Patent US 6514552 B1
In my research for this post, I came across a fantastic article from 2015 by Karen Paterson. Karen is owner of Hula Daddy Kona Coffee, a member of the Hawaii Coffee Association, the Kona Coffee Council, the Kona Coffee Farmers Association, and the Specialty Coffee Association of America. A number of the references I’ve used here were found via Karen’s post. It’s well worth checking out her full post which leaves no stone unturned. Here’s how she summed up her findings:
Brewing coffee beans between 3 and 10 days after roasting is best. If coffee cannot be consumed before 10 days after roasting then freezing the coffee is a good alternative.The enemies of coffee freshness are heat, water and oxygen. Properly frozen coffee beans defeat all three.
Freezing Coffee Beans Keeps them Fresh
Kaladi Coffee not only recommend freezing for longer storage, they also utilise freezing at their roastery.
“We place our beans in the freezer directly after roasting so the staling process does not begin before you, the customer, purchase our coffee. Gasses expand at higher temperatures and contract at lower temperatures. Lowering the temperature of these gasses slows their rate of dissipation. Studies show that for every decrease in temperature of 10 degrees celsius, the life of the coffee increases by 50%. Most home freezers are capable of temperatures of -10 to 0 degrees fahrenheit, sufficient enough to store coffee beans for several months without degradation.”
Granite Ledge Coffee
Granite Ledge is another roasting company that advocates freezing.
Should fresh coffee be kept frozen?
Yes. If frozen when fresh, whole bean coffee can remain fresh for up to 9 weeks (+/-).” … “Is it best not to freeze coffee? Yes. But if you have a quantity of whole bean coffee that will not be consumed within 10 days to 2 weeks, the effects of freezing is negligable when compared to the effect when beans are left to degrade at room temperature.”
F. Gavina & Sons (Don Francisco’s Coffee)
Here’s an article about a study conducted by accredited Q-graders who also found that freezing works. Worth noting is that this is the first roaster I’ve seen who also recommends storing coffee in the fridge. This isn’t something I’ve seen recommended by anyone else and I’d be looking for more supporting evidence before I could recommend fridge storage.
“The best place to store coffee is in an airtight container in the freezer, which prevents the coffee from coming into contact with air and protects it from temperature changes. Additionally, storing the beans whole helps keep the rich aromas and tastes locked in longer.”
Don Francisco’s Coffee Unveils New Study That Answers the Age Old Question: To Freeze or Not to Freeze
Conspiracy Theory Time
Put your tinfoil hat on for this next bit. I generally don’t buy into conspiracy theories, but it has occurred to me that freezing coffee might be discouraged by some roasters as perhaps it’s not good for frequent, repeat business. If freezing works for you, then it means you can buy coffee cheaper and less often.
There’s more than enough support from reputable coffee industry folks, for storing coffee beans in the freezer, to warrant trying it. Next time you buy a bag of coffee, freeze half of it and brew it a few weeks later. I think you’ll be pleasantly surprised.