How’s This Idea For Fresh Coffee Bean Storage? - Page 2

Want to talk espresso but not sure which forum? If so, this is the right one.
Qrumcof
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#11: Post by Qrumcof »

jpender wrote: Adding CO2 won't change the total amount of O2 or the partial pressure.
That helps a lot (not an exact science / anecdotal evidence). I know for a fact freezing the beans keeps them fresher longer, but I only assumed that vacuuming the air out and then freezing would be better.

Great idea; - I will test full vacuum versus the weaker vacuum (comparable to the food saver vacuum devices), I'm breaking up a pound into 5 parts (1-2 shots a day), and 1 of 4 frozen bags will be full vacuum. So I will probably be able to test all seven coffees in the next month or so.


LONG VERSION:

I don't know if frozen beans taste as good as the same fresh roasted beans did a couple of weeks/months later, but the frozen beans are definitely close enough to where I cannot tell the difference without methodically testing. Of course I want to optimize for the perfect shot, LOL, so if I notice a difference I will have to switch to buying those expensive little 12 ounce bags and eat shipping.

I did just buy a $600 chamber vacuum sealer, and I like it a lot (https://www.amazon.com/gp/product/B07YL ... UTF8&psc=1).

It can vacuum 6-9 16oz mason jars at the same time, and it's only 14"x15". It would've paid for itself quickly with the cost of coffee beans, but now that I've learned to cook at home (pandemic) I found so many uses it will eventually pay for itself even if I end up not using it for the beans.

The chamber vacuum sealer works differently than the disposable ones.. I can adjust the strength of the vacuum by changing the setting of how long it vacuums before the sealing cycle begins, and it also seals the thick mylar bags that the other units cannot (by adjusting the "seal" time for a longer duration).


VACUUM --- OR NOT?

I came across a discussion where there was a chorus agreeing that the strong vacuum of the chamber vacuums suck the flavor out of coffee. And the reasoning made sense. Because if coffee is offgassing, it seems like pressure instead of vacuum would keep it fresher longer (like a bottle of pop is under pressure, and a vacuum would probably suck away the fizz).

But I don't know what the relationship is between offgassing and the freshness of the coffee.. Is offgassing the coffee flavor boiling away? Or is it only a coincidence that when offgassing completes we are one step closer to stale coffee.

A strong vacuum does change boiling points, so it's conceivable that a strong vacuum could be boiling away flavor at room temperature (probably the coffee we smell). The boiling point of [car] antifreeze increases 3° for every pound of pressure. If the same is true for water, then 28HG of pressure would change the boiling point to ~125°. The thing that concerns me is the various flavor elements that make coffee probably have different boiling points; - so it's easy to imagine flavor boiling away at room temperature, and vacuuming could make it boil faster.


IN FAVOR OF VACUUM?

Fresh beans deserving of freezer storage in the first place, are still offgassing. A bag I vacuumed yesterday slightly puffed in about 10 minutes (Offgassing), so there is no more vacuum, and the air has been replaced with the CO2 Offgassing (i'm only guessing but this seems to me the best you can do without expensive equipment to add pressure and CO2 instead of a vacuum). So maybe if the coffee is fresh enough it can tolerate vacuum sealing (but not repeated cycles). I believe vacuum packing does indeed pump a little bit of flavor out of the beans (ages the beans maybe a day?), but in return stabilizes the beans for long-term storage.

Jeff

#12: Post by Jeff »

Bags loosing vacuum that quickly may just be the beans puncturing the pouch. Even with commercial pouches, I often have to use a paper or muslin inner bag to prevent it. Puncture failures can happen weeks or months later. I've seen it happen with greens, roasted coffee, dog and cat kibble, parrot pellets, rice, ... , so it's unlikely offgassing.

jpender

#13: Post by jpender »

Qrumcof wrote:A strong vacuum does change boiling points, so it's conceivable that a strong vacuum could be boiling away flavor at room temperature (probably the coffee we smell). The boiling point of [car] antifreeze increases 3° for every pound of pressure. If the same is true for water, then 28HG of pressure would change the boiling point to ~125°. The thing that concerns me is the various flavor elements that make coffee probably have different boiling points; - so it's easy to imagine flavor boiling away at room temperature, and vacuuming could make it boil faster.

All boiling does is increase the rate of vaporization; it doesn't drive it. What matters is the temperature and partial pressure. Air at atmospheric pressure has very little CO2 to counteract CO2 release from the beans. Vacuuming doesn't change this very much. Pressurizing with N2 doesn't change it at all.

An analogy is a pan of water. You can heat it to boiling. But if you don't it will still evaporate unless the humidity is really high.

Qrumcof
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#14: Post by Qrumcof »

Jeff wrote:Bags loosing vacuum that quickly may just be the beans puncturing the pouch. Even with commercial pouches, I often have to use a paper or muslin inner bag to prevent it. Puncture failures can happen weeks or months later. I've seen it happen with greens, roasted coffee, dog and cat kibble, parrot pellets, rice, ... , so it's unlikely offgassing.
Can I try wax paper to protect the Mylar (I don't have a paper bag).
That the bag must be leaking was my first thought as well.

After two in a row did exactly the same thing (lost the vacuum in minutes/maybe 10 maybe 20),
Then I sealed some three month old beans, and it took an hour or 2 for the bag to puff..
So it made sense that all beans were offgassing slower.

To add to the confusion I sealed some rice, and I thought it was settled, but by the next morning the vacuum released too.

I know mylar can crack open, which is why I ordered the 7.2 mill thick mylar/foil bags.. Do you think bags this thick would be prone to leaking?

I set the seal time to 8-seconds and the seal looks good. Since you said rice and coffee both might puncture a bag, maybe I need to do another test with some other material?

Jeff

#15: Post by Jeff »

I use paper bags from a restaurant supply house or muslin bags used for spice storage. Waxed, parchment, or the like would probably work as well. Bags, for me, are easy as I weigh out a week's worth directly into them, then seal.

I can't comment on Mylar, as I use high-temperature bags primarily for sous vide. They're thicker than standard bags, but similar material. All it takes is an invisible pin prick to have a failure and coffee beans seem to have enough sharp spots to cause them.

Qrumcof
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#16: Post by Qrumcof »

Jeff wrote:Bags loosing vacuum that quickly may just be the beans puncturing the pouch. Even with commercial pouches, I often have to use a paper or muslin inner bag to prevent it. Puncture failures can happen weeks or months later. I've seen it happen with greens, roasted coffee, dog and cat kibble, parrot pellets, rice, ... , so it's unlikely offgassing.
You were right. It appears to be the mylar bags.

I probably went through 7-9 bags, and every single one would lose vacuum. The seal looks strong.. In the previous test I wrapped the contents of both in wax paper, and still no good - they both lost vacuum fairly quickly.

The first success I've had, where both bags are still hard like a little bricks several hours later. I vacuum sealed a cheap 3 mill plastic bag over the mylar bags (vacuumed both bags).

Meanwhile coffee is going stale; what a pita.

aussiecoffeebuzz

#17: Post by aussiecoffeebuzz »

This works pretty well for me

https://www.anacondastores.com/camping- ... BP90029613

You can make the bag any size you want, and re vacuum seal them.