Recently articles quoting two respected coffee professionals stated that roasted coffee beans should not be frozen because the water trapped inside the bean will freeze, expand and crack the bean. Starbucks Expert: How to Brew Coffee, Avoid Common Mistakes (quoting Major Cohen) http://go65g6Boo.gl/; Don’t Freeze Coffee, and Five Other Tips for Treating Beans (quoting Sherri Johns) http://goo.gl/mXMuHN The articles raise questions. How do these experts know that ice in the beans will cause cracks? Roasted coffee beans are full of cracks. How can you tell which cracks are from roasting and which from freezing? In addition, what difference does a few more cracks in the bean make? Neither article stated where the author got the information about freezing and cracked beans.
There are hundreds of theories about storing roasted coffee but very little valid research. Every coffee pundit is convinced that her particular method of storing coffee is correct and that everyone else’s method is wrong. The belief in freezing or not freezing roasted coffee beans goes beyond vigorous discussion. The discussion approaches the level of religious wars. Coffee “experts” are either for or against freezing. You are either a “freezer” or an “anti-freezer.”
There is no middle ground. Whichever side you choose you will be shunned and punished by the opponents. As an example, a small coffee shop owner in Baltimore froze some coffee beans it had purchased from a large roaster. He says the roaster told him that they were angry because he froze “their” beans and that they wouldn’t sell “their” coffee beans to him anymore. http://goo.gl/q1dzBH
The reasons given for not freezing coffee are varied:
- beans will crack from freezing.
- beans will attract odors from the freezer
- beans will attract water from the freezer
- beans will attract water when taken out of the freezer
- bean shelf life is not extended by freezing
- beans that have been frozen degrade very quickly after thawing
- freezing breaks down the flavor oils in the bean
However, there is no research, of any kind, which supports any of these reasons.
All of the coffee pundits agree that coffee is best brewed from three to ten days after roasting. The freezing/no freezing discussion comes up when the consumer cannot brew all of her coffee beans in that time period and has to store them.
The National Coffee Association recommends not using a freezer for short term coffee storage. Their reasoning is that taking the beans in and out of the freezer exposes them to moisture in the air which will degrade their flavor. However, they recommend using a freezer for long term storage of roasted coffee. http://goo.gl/mlGbVl
Kalidi Coffee, a major roaster in Denver, freezes their roasted coffee. On their website they say: “Freezing is one practice that sets Kaladi Coffee Roasters apart from other roasting companies. 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.” https://goo.gl/eb50E5
Andrew Hetzel, SCAA Board Member and coffee consultant, says ” I decided to try it myself and found that immediate freezing after roasting to be the single most effective method of delaying spoilage, hands-down. I now store coffees, mostly reference samples for purchases and experimental client blends in a dedicated coffee chest freezer for sometimes as long as a year after roasting without significant degradation, though frozen coffee will not have the same full usable shelf life of a fresh product once thawed. As with most coffee topics, scientific proof is practically nonexistent; however, I am entirely confident of the results …” Comment on Jay’s Strange Blog http://goo.gl/q1dzBH
Coffee Review states that “Freezing, however, is an excellent way to preserve whole-bean coffee if you do not intend to drink it within a week. Seal the beans in a freezer bag, put the bag in a part of the freezer that does not lose temperature every time you open the door, and remove only as many beans as you intend to consume in a day, returning the rest to the freezer. Thaw the liberated beans before grinding and brewing.” http://goo.gl/T0Khkj
A number of sites that advocate freezing roasted coffee refer to “studies” showing that freezing prolongs coffee freshness. However, they all appear to be referring to a book by Michael Sivitz. As stated on the Granite Ledge Coffee website: “Coffee can be stored in the freezer effectively if consumed within two months or so. While this discovery can contradict conventional belief, the empirical evidence is overwhelming.If interested in this subject, we recommend reading the comprehensive text written on the subject: Coffee Technology, Michael Sivitz, AVI Publishing Co., Westport CT, 1979″ http://goo.gl/nOkWTW
What Sivitz said is: ” Freezing coffee beans and …[roasted and ground] coffee is not often practiced, nor its usefulness appreciated. But 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: 1) water reactivity is immobilized; 2) volatility of aromatics is reduced by 4-fold: 3) rates of oxidation are reduced about 50 percent for each 10° C reduction, hence about 15-fold: and 4) the vegetable-like coffee oil is congealed, thereby reducing movement of volatiles dissolved therein from convective rates to diffusional rates. Altogether, roast beans keep for months and …[roasted and ground] for many weeks, which is at least a 30-fold freshness factor for beans and over a 15-fold freshness factor for …[roasted and ground].” Coffee Technology, p.280
There are three published experiments about freezing coffee beans. They all used a panel to taste coffee made from beans that had been frozen against the same not frozen beans. The first Coffee: To Freeze or Not by Ken Fox http://goo.gl/wFB2RY compared sixty-four shots of espresso, half from frozen beans and half from never frozen beans. Half of the frozen beans were held in the freezer for four weeks, the other half for eight weeks. The shots were judged by the author and two espresso loving friends based on crema, flavor/aroma and preference. The author found that there was no statistical difference between the scores of the frozen vs the unfrozen beans. He concluded that “…it has demonstrated that freezing, done shortly after roasting in a very cold freezer delays staling for at least two months and hence extends shelf life for at least that long.”
The second To Freeze or Not to Freeze http://goo.gl/KEX3FI was done by the Don Francisco division of F. Gavina & Sons. In the study, the same roasted coffee was split three ways. One sample was put into a freezer at 0 F degrees, the second was placed in a refrigerator at 32 F degrees and the third was stored on a counter at 72 F degrees. The samples were brewed and cupped every two weeks for 12 weeks by a panel of three Q cuppers. Their conclusion was “… the best cup of coffee is achieved starting with whole beans stored in an airtight container in the freezer for a maximum of 6 weeks.”
The third Taste Test: To Freeze or Not to Freeze Coffee Beans http://goo.gl/lF5alQ was done by Erin Meister, a barista trainer at Counter Culture coffee roasters. She split a sample of coffee and froze half of it for two weeks. (Part of her taste test also included coffee in Ziploc bags vs sealed one way valve bags.) The other half was stored at room temperature. The frozen packages were all opened and allowed to defrost in the open before brewing. She then had seven people taste the coffees and rate them on aroma, acidity, body and aftertaste. The unfrozen beans scored significantly higher than the frozen beans. However, there is an anomaly in the test that suggests it may be flawed. All of the ground coffees both frozen and unfrozen scored higher then their whole bean cohort. It isn’t possible that eight samples of two-week old ground coffee would consistently outrank the same two-week old whole bean coffee, whether it was frozen or not.
Here are my conclusions:
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. If coffee is going to be frozen, it is best to seal it in an airtight container immediately after roasting and then freeze it. If the coffee beans can’t be frozen immediately after roasting, placing the whole beans in an airtight container and freezing is still a good alternative. Double Ziploc bags, sealed one-way valve bags, airtight coffee containers and vacuum sealed bags are all good ways to store frozen coffee. If coffee is going to be partially extracted from the frozen sample, exposure to air and moisture should be minimized.
Hula Daddy Kona Coffee is the winner of the 2014 Kona Coffee Cupping Competition. Karen is a member of the Hawaii Coffee Association, the Kona Coffee Council, the Kona Coffee Farmers Association, and the Specialty Coffee Association of America. She is also the author of a number of articles on Kona Coffee including: Coffee Fraud http://www.huladaddy.com/?p=2337: Kona Coffee Farmers at a Crossroad http://www.huladaddy.com/?p=696 ;How Typica is Your Kona Coffee? http://www.huladaddy.com/?p=710 ; Are Roasters Eroding the Kona Coffee Brand?http://www.huladaddy.com/?p=952; Coffee Cupping Competitions – Real or Random Chance? http://www.huladaddy.com/?p=1670 ; Seven Easy Steps to Become a Gourmet Coffee Taster http://www.huladaddy.com/?p=1785 ; How to Brew Coffee Using a Pour Over Filter http://www.huladaddy.com/?p=1754; Before You Buy an Automatic Single Serve Coffee Brewer http://www.huladaddy.com/?p=1899; Siphon Coffee Brewers Suck! http://www.huladaddy.com/?p=2026; Sweet Coffee http://www.huladaddy.com/?p=2144;What Color is Your Coffee Roast? http://www.huladaddy.com/?p=4 You can email her at firstname.lastname@example.org