I could never reach a conclusion on this topic, but I had a few thoughts.
Until someone actually performs controlled experiments, we are all in the dark. The internet is filled with undocumented sources and false, untested claims.
The oils in coffee do become rancid after awhile like most food oils. If the reaction that produces this rancidity is slowed by cooler temperatures, then freezing could be beneficial. Many chemical reactions are heat sensitive, so this is one avenue to pursue. Whether household freezer temperatures are low enough to slow the reaction down to a significant level is left to experiment.
The heterocyclic compounds in coffee that produce its smells have a volatility that increases with increased temperature. I rationalize this through the kinetic molecular theory of heat. My reasoning is the following: the added heat produces more molecular agitation, resulting in more smell compounds being ejected. Cooler temperature mean smaller loss rate of smell molecules. There is a relative volatility to consider here, as flower, fruit and herb smells are the most volatile and may be lost at a high rate even with household freezer temperatures.
When you remove the beans stored in the freezer, the humidity in the air attaches to them much like condensation on a cold glass. Repeated exposure like this may impart bad flavours or ruin the beans. Maybe individual containers for daily use are recommended, rather than one large one that is repeatedly put back in the freezer.
Coffee beans, especially light roasts, have some moisture content after roasting, do they not? Would this be a problem when we freeze the beans?
If anyone has any ideas on these points, I would love to hear them as I am still trying to give a good answer to the people who ask me this question. Has anyone seen an actual study done for coffee?
I'm not personally aware of any scientific study, but my recommendation is always "try it for yourself." Chances are you have a freezer. It's fairly possible you have some sort of glass jar around. Fill the jar with fresh beans, freeze for a few weeks, take out the jar to thaw, and brew. See what you think. It's not an infallible thing, clearly, as the OP is seeing some very uncommon results, but I even draw the line at a month or so. If I'm storing coffee that long, I'm forgetting about it. It's really just a method that seems to work well at preserving beans a bit longer than their natural shelf life at room temp. My findings have never been what cwatson claims - I've never experienced a discernible off-taste due to freezing. However, you may find differently. And that's exactly why I recommend people to try it themselves. Waiting for a study to be completed will take far longer, after all. Though, if you really want to see a breakdown of the science behind frozen coffee preservation, I couldn't blame you.
"Frost Free" is the spawn of Satan as is trying to use the freezer at the top or bottom of your fridge. Common sense is all else that is required here.
1.) Don't refreeze any food product, just don't. (frost free included) 2.) Freeze in as close to a vacum as you can. 3.) Thaw frozen dry goods at room temp still sealed to minimize condensation. 4.) Once thawed consume it in a timely fashion. In my experience beans that have been frozen tank more quickly after thaw. I freeze in batches small enough i have to thaw about every day.
Try it if you can't make work for you don't do it. I think its pretty short sited to discount the dozens of accounts of successes by accomplished individuals that can make it work for them.
You know those people that want to tell you how to raise your kids but have none of their own? That is how i feel when someone with a kitchen appliance tells me how the merits or dis-merits of my machine or how to use it.
The above comments are pretty much solid stuff. I will add that I discern no degradation in quality, and i've tested using 9 day old q way valve coffee with the same coffee I froze at day 3 post roast then thawed e days later. I waited 2 days to allow the coffee to rest a bit. It was every bit as good as my 9 day prime coffee, with the slight differences in bloom/crema.
I would guess when freezing a drip blend, any differences would be less detectable.
I took the liberty of using one of JasonBrandtLewis's options and I quote Ken Fox and Jim's joint study: "On the "Features" section of this website is an article by Ken Fox describing an experiment comparing previously frozen coffee to fresh, never frozen coffee. It concluded that freezing was a reasonable way to preserve coffee intended for espresso use, for a period of at least two months".
And I do idolize Jim and everything he brings to the coffee scene. This is an argument that we should all be respectful on this forum to each others feelings.
Freezing is a reasonable way to, etc. 'nuff said. And no other claim, no more no less. This has helped me tremendously when I order 4-5 pounds to save shipping costs and haing to store a portion. If these guys feel little harm is done to their delicate palate then I don't worry about my untrained one. Thanks for allowing me to express my feelings on this delicate subject.
I actually just bought Red Bird's espresso roast. After wandering around their site I found this little bit of info about freezing which might be helpful:
"If you order the 5 pound bag and want to store it, the best way is to vacuum seal it with something like a Foodsaver, and then freeze it. Coffee that is not vacuum sealed will still age in the freezer, but vac-sealing and freezing seems to stop the aging process almost completely." -From Red Bird Coffee Website http://redbirdcoffee.com/aboutcoffee.html
It seems to me by that oxygen is the culprit with most food so getting rid of that might actually make what they're saying true...Even if the taste may change a little.
I have been freezing roasted espresso beans for the last couple years and have not had issues. i re-use the resealable 1 lb. bags that Vivace and Ecco ship their coffee in. These have the one-way valve that let air out as the beans off gas. I make a decent effort to get out as much air as possible before putting them in the freezer. My Sub-Zero freezer is set at 0 degrees and have ground beans that were frozen for up to 6 weeks with great results. A truly airtight seal is essential, and a below freezing temperature seems to do the trick. I have tried the mason jars as well, and it worked well enough, but you have to fill the jars to eliminate as much air as possible. A half filled jar was my one downfall recently and I wasted a 1/2 pound of Handsome espresso.
... I have tried the mason jars as well, and it worked well enough, but you have to fill the jars to eliminate as much air as possible. A half filled jar was my one downfall recently and I wasted a 1/2 pound of Handsome espresso.
I agree that getting the air out is crucial to successful freezing. I seem to recall reading a year or so ago, a semi-scientific test done by one of the engineers on either this site or Home Barista's. The conclusion was that freezing when done right, works pretty damn well for practical purposes.
I have experimented with it. It is a yes and no kind of answer. Yes just a vacuum will add a few days until the beans are stale but other then commercial machines the oxygen can not be lowered enough to stop oxidation. Limiting exposure to oxygen is just one part of the equation, the beans will still degas co2. Freezing below -10f stops the beans from degassing and seems to stop any oxidation or at least slows it to a crawl, I stopped pulling a vacuum on my jars and I can not taste a difference from a vacuumed jar and a non vacuumed jar once they have come to room temp.
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