Freezing Espresso Coffee, Part Two - Page 2

Beginner and pro baristas share tips and tricks.
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JohnB.
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#11: Post by JohnB. » Mar 19, 2009, 12:58 pm

I've been vac bagging(Foodsaver) & freezing my roasted beans for over a year & a half now. I don't have Jim's cupping abilities but I've been very happy with the results. I break the espresso down into 2 day lots & the vac pot/press beans into one use bags. The beans are stored in an upright storage freezer set to 0*F. Just getting into home roasting & I also vac bag/freeze my greens in half pound portions.
LMWDP 267

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another_jim
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#12: Post by another_jim » Mar 19, 2009, 1:02 pm

I'll defer to Ken, but I think it's a typo. He puts the coffees in valve bags immediately after roasting, then freezes them.

The major point of this test, along with all the other accounts we have here, is that coffee in the freezer does not simply go stale more slowly than at room temperature. Whatever happens is different, since the classical signs of staleness (no aroma, flat and/or bitterish taste) do not occur. If freezing does change coffee; it's in some way we haven't been looking for.
Jim Schulman

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JonR10

#13: Post by JonR10 » Mar 19, 2009, 1:30 pm

Wow, this was a very cool experiment, and nicely done!

Thanks guys - for the effort to help us all understand (or not) just a bit more. Once again, it seems as though more we discover the more we open our eyes to areas that we don't fully undertstand. :mrgreen:
Jon Rosenthal
Houston, Texas

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cafeIKE

#14: Post by cafeIKE » Mar 19, 2009, 1:58 pm

sweaner wrote:Excellent experiment. Any thoughts on freezing the coffee in a regular refrigerator/freezer.
This was discussed in Rate of coffee staling.
IMO, two months seems fine @ -20°C / -4°F.

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GC7

#15: Post by GC7 » Mar 19, 2009, 1:59 pm

I suspected it might be a typo but confirming would clarify for others.

I do believe that waiting a bit for some degassing in the bags to purge O2 before freezing OR vacuum sealing as I described would improve the process.

JohnB - I love my foodsaver unit. I store any greens not being used within a couple of months in vacuum bags. I divide them up between what can fit into my 57* F wine cabinet and the refrigerator at 4* F. I have not subjected greens to freezing.

Ken Fox

#16: Post by Ken Fox » Mar 19, 2009, 2:55 pm

GC7 wrote: I have a question and perhaps a suggestion for improving storage more.

You state
"The test coffees that were frozen were packaged immediately after freezing into plastic valve bags (with the valve taped over), placed into a very cold chest freezer at around -15F, where they reposed until defrosted in these bags couple of days before the comparison tests were conducted. The fresh-never frozen coffee had degassed for 4-5 days before it was used in the test."
The above (posted quite late last night after Jim and I agreed on the text, itself not a simple process!) had a typo in it which I have now corrected. It should have read "The test coffees that were frozen were packaged immediately after roasting into plastic valve bags . . . . "

Thanks for picking this up.

My (Ken's) normal practice is not to use valve bags for freezing my own coffee, rather to use nearly air-tight Mason type jars. The coffee is frozen just out of the roaster in a sealed jar and the jar is not opened again until the jar (or valve bag, in this case) has come back up to room temperature after defrosting, prior to use.

ken
What, me worry?

Alfred E. Neuman, 1955

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JohnB.
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#17: Post by JohnB. » Mar 19, 2009, 5:29 pm

GC7 wrote: JohnB - I love my foodsaver unit. I store any greens not being used within a couple of months in vacuum bags. I divide them up between what can fit into my 57* F wine cabinet and the refrigerator at 4* F. I have not subjected greens to freezing.
Then I assume you meant to say 40*F?? Some good info on greens storage here: http://www.terroircoffee.com/content/view/144/28/
LMWDP 267

ManSeekingCoffee

#18: Post by ManSeekingCoffee » Mar 19, 2009, 5:48 pm

Terrific follow up to a great first article. I've been wanting more of this kind of empirical evidence for coffee practices for quite a while. Following your experiences, I typically vacuum seal up surplus beans from the roaster upon receipt and store them in my standard freezer at around 0 degrees (F). I rarely notice any difference between the frozen and fresh beans. In the few instances when I have, my suspicion is careless packing/contamination on my part.

I'm curious about whether you had a chance to follow the frozen coffee out several days post freeze. I typically only freeze a couple of days supply, but I find it hard to believe that there is simply no chemical change to freezing (and aging it). Is the coffee merely in suspended animation. I'd suspect that it ages faster once thawed. I seem to remember this suggestion from the first article as well? Certainly if it did age more quickly upon thawing, that's an argument for bagging up small doses as opposed to an entire bag.

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another_jim
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#19: Post by another_jim » Mar 19, 2009, 6:10 pm

ManSeekingCoffee wrote:I'm curious about whether you had a chance to follow the frozen coffee out several days post freeze. I typically only freeze a couple of days supply, but I find it hard to believe that there is simply no chemical change to freezing (and aging it). Is the coffee merely in suspended animation. I'd suspect that it ages faster once thawed.
It's probable that you are right.

Nitrogen pressurized Illy is "progeria coffee," tasting acceptable for a few days, then dying rapidly, almost literally on one's tongue, on the third. However, we noticed no ultra-rapid decline like this. Testing for a slower decline, just like testing for any subtle effect you are not certain of, requires a large number of trials to nail anything (it's easier if one knows exactly what one is looking for, since one can design a far more elegant and telling experiment).

So far, I've been completely incapable of even characterizing how frozen coffee's taste changes in relation to fresh. So the preliminary for experiments of this sort would be for me to cup very light roasted coffees that have been frozen very badly and slap-dash, in the hope of finding an obvious gustatory smoking gun. Once that is found, it may finally be discernible it as a subtle whiff in properly frozen coffee.

It would make a terrific parlor trick, and earn anyone doing it lots of cuppers bragging points. But it would still be meaningless in terms of using or not using freezing when one needs to preserve a roasted espresso blend.
Jim Schulman

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GC7

#20: Post by GC7 » Mar 19, 2009, 6:16 pm

JohnB. wrote:Then I assume you meant to say 40*F?? Some good info on greens storage here: http://www.terroircoffee.com/content/view/144/28/
Yep - mixed up my fahrenheit with centigrade :oops: