Better Espresso thru Freezing - Page 4

Beginner and pro baristas share tips and tricks for making espresso.
Ken Fox (original poster)
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#31: Post by Ken Fox (original poster) »

shadowfax wrote:Try taking one of those one way valves apart. They are simple, cheap devices that don't work terribly consistently at room temperature. they rely on an oil-lubricated rubber disk sealing against a plastic orifice, and I don't think that the oil seals right when frozen.
The CEO of Pacific Bag, major seller of these sorts of bags, either posted here or said to me verbally (I forget which, maybe both) that these one way valves have a drop of oil in them that will freeze in the freezer, and the result is that the valve will freeze in either the open or closed position. It is not intended to be used as a one way valve in a freezer. I tape over the valve myself when I put a valve bag in the freezer.

ken
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gscace
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#32: Post by gscace »

cannonfodder wrote:That is unfortunate. I have been freezing my home roasts, and commercial roasts when I get several pounds at a time with good results. I do not vac pack my beans, they just go into a mason jar. On commercial roasts I tape over the valve and toss them in the chill chest. With prolonged storage, I do notice that the beans will age more rapidly once they go into service. However, that is after prolonged storage, months not weeks. When I freeze home roast, I will use pint jars instead of quart. That is about 2-3 days of coffee for me so I can keep what is in the grinder at its prime window. My chest freezer is around -20F.
IMO it's a waste of time to vacuum pack coffee if it's fresh from the roaster. The coffee degasses like crazy, so any vacuum you pump is gonna be lost really quickly. I store in "ball" jars with replaceable gaskets and freeze.

-Greg

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JohnB.
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#33: Post by JohnB. »

gscace wrote:IMO it's a waste of time to vacuum pack coffee if it's fresh from the roaster. The coffee degasses like crazy, so any vacuum you pump is gonna be lost really quickly.
-Greg
I always let the beans degas for several days (3-4) before vac bagging as I want to be able to use the beans soon after removing them from the freezer. I've left roasted coffee in the freezer for 2-3 months that was vac bagged using a Foodsaver & the bags were still just as tight as the day they went in. Let the vac bagged beans warm up on the counter for an hour or two & the bag will start to swell as the beans begin degassing again.
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shadowfax
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#34: Post by shadowfax »

gscace wrote:IMO it's a waste of time to vacuum pack coffee if it's fresh from the roaster. The coffee degasses like crazy, so any vacuum you pump is gonna be lost really quickly. I store in "ball" jars with replaceable gaskets and freeze.

-Greg
2 points. First, vac-packing removes oxygen and moisture from the air in the jar (in a humid climate like Houston, especially), and when the coffee degases, it re-fills that space with (mainly) CO2 rather than the atmospheric mix of gases including O2. My understanding is that CO2 is much less reactive with the cells of the coffee beans, and doesn't cause aging like oxidation does. So, assuming that excess moisture and oxygen are both things that could cause problems, and that even if the vacuum is refilled, it's refilled with CO2 and moisture from the beans, a loss of vacuum isn't necessarily a bad thing. Second, my experience is just like John's--I can't quantify the vacuum loss, but I can say that given fresh beans 2 days post-roast that are vacuum sealed in a mason jar, after several weeks of freezing, and then allowing to thaw for 12-24 hours, the vacuum is still quite powerful. I've let one or two sit for days here and there out of the freezer (without relieving the vacuum manually), and they still seem to have a (very weak) vacuum.

I can't speak to the added utility of vacuum sealing in a freezing situation, but in any case, degassing does seem to be one of those chemical processes that's virtually halted by freezing, and I don't think it's a realistic dimension of the issue.
Nicholas Lundgaard

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GC7
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#35: Post by GC7 »

If one takes the commonly used formula that reaction rates double every 10 degrees of temperature increase and one takes the production of CO2 from roasted beans as a simple chemical reaction you can estimate the decrease in production with freezing. If we go from a 70* room temperature to a -10* freezer then the rate of CO2 production from the beans will be 256-fold reduced. That is essentially stopping the process over the freezing interval.

I have recently used my foodsaver to freeze beans and the package (unless it breaks which happened once) remains tightly packed. I have also put tape over one-way valve bags. I can't tell the difference in the cup so far but both methods preserve beans well.

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Peppersass
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#36: Post by Peppersass »

I still haven't gotten an answer to one of my freezing questions:

When you throw a 12oz or 16oz bag from a roaster in the freezer, then later remove it for use, do you

1) defrost and use the whole bag, or
2) Take what you need for a few days or a week, reseal the bag and throw it back in the freezer, or
3) Break it down into different containers and put what you won't be using back into the freezer?

If #3: Do you break it down while still frozen? If so, what about the potential for condensation and freezer burn? Or, do you let the coffee defrost completely and refreeze the unused portion (seems like a bad idea)?

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shadowfax
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#37: Post by shadowfax »

I won't bother speculating on how or whether or not #2 or #3 are safe, but I can say that method #1 is the one that is confirmed to be safe by blind testing, and also seems to me to be clearly the safest route. If you feel the urge to put the excess back in the freezer, that's a good cue that you could just put smaller quantities of beans in the individual containers you're using (and/or get smaller containers).
Nicholas Lundgaard

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sweaner
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#38: Post by sweaner »

Dick, I never re-freeze the beans. I usually place the entire 12 oz bag into a vacuum bag, the now discontinued Reynolds HandiVac. :cry: I then freeze that. When I am ready to use it I remove and let it come to room temp. Then I use the entire bag. If/when we get a second freezer I will likely go to the mason jars.
Scott
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Address7
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#39: Post by Address7 »

I have been following this post for a while with interest, as I like trying different batches from all over the country, and I feel better about the economics of it when I order a 5 lb bag. Note: I have only dealt with roasters who 'roast and post' and generally order blends that are said to be best (by the roaster) between days 5 and 15 post roast, but this is what I do:

1) Upon receiving the coffee, I open the bag and disperse it amongst approximately 8 regular 12 oz Mason jars, filling as much as possible, including settling the beans.
2) I loosely attach the lid and wait about 2 hours at room temp before sealing. Since the roasts I get are between 2 - 4 days old, they start gassing immediately. The CO2 will displace the oxygen in the jar, as CO2 is heavier. Leaving the lid open a bit allows the oxygen to escape.
3) I seal them and pop them in a regular freezer.
4) I pull out one jar at a time. In the morning, I open the jar to let the beans degass. By the next day, they seem to be at about the right stage to start making espresso. I do not re-freeze, but I do keep the lid on tight between uses. The coffee seems to be good for up to about 4-5 days before the crema really falls off. I do notice that the beans age faster than just using a fresh, never frozen 12 oz, but only by about 2 days.

Note: I am in Utah, we have very low ambient humidity so I don't worry about moisture.

Enjoy your experience, James

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cafeIKE
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#40: Post by cafeIKE »

GC7 wrote:If one takes the commonly used formula that reaction rates double every 10 degrees of temperature increase ...
10° Celsius. Room temp [20°C] to -4F [-20°C] is 4x10°C so the reaction rate 1/16th.