Vacuum Setting for Storing Coffee

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Tcreast

#1: Post by Tcreast »

Hi,

I found some old threads on using a vacuum sealer to store coffee. Since then, I've been using an old chamber-style sealer (Vacmaster VP112S) to seal my beans in mason jars.

I'm using the maximum vacuum setting (I figured why not?) but now suspect that I'm sucking out some of the aroma of the coffee. I was surprised to find that my beans tasted kind of "flat" after being stored this way for a few weeks.

For reference, the highest setting is 29.3 Hg, which if I undertand correctly is ~98% vacuum.

So my question is, do you all have any idea what the optimal setting would be? The model I have offers 5 choices: 23.5 Hg, 26, 27.5, 29, and 29.3. It seems like 23.5 would be ~78% vacuum and 26 would be ~87%, so perhaps one of those?

Thank you.

Jeff
Team HB

#2: Post by Jeff »

I seal and freeze at 98%. At 9-12 months (I'm not doing well at catching up with my early-COVID buying spree), I find the beans still very enjoyable.

I think about it in terms of available oxygen. Whether that's "right" or not hasn't been tested with "specialty" coffee, that I know of. I seem to recall 2% O2 as being referred to, perhaps by Illy. That would be a bit more than 90% vacuum.

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Tcreast (original poster)

#3: Post by Tcreast (original poster) »

Interesting. Thanks, Jeff.

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LBIespresso
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#4: Post by LBIespresso »

Google/YouTube let me down so I'll ask here: If you put a wet sponge in a dry mason jar and vacuum sealed it would some of the water leave the sponge? Is this a relevant question to the voc's locked inside the coffee?
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Jeff
Team HB

#5: Post by Jeff »

You won't get that far, as the water will boil. Some professional chamber sealers will automatically stop when that is detected to help keep the oil clean.

jpender

#6: Post by jpender »

LBIespresso wrote:Google/YouTube let me down so I'll ask here: If you put a wet sponge in a dry mason jar and vacuum sealed it would some of the water leave the sponge? Is this a relevant question to the voc's locked inside the coffee?
Yes, some of the water will leave the sponge. For that matter, if you just put a wet sponge in a dry mason jar some of the water will leave the sponge. The question is: how much? And the answer to that is that it depends on a number of factors. Boiling speeds things up for sure. But that won't happen with a cheap Foodsaver sealer; you have to remove 97-98% of the air for water to boil at room temperature. So you could avoid that by limiting the vacuum to 95%. That would take the oxygen level down to about 1%, comparable to what the Coffee Freshness System achieves.

The real question you're asking -- how vacuum sealing affects volatile aromatic compounds in coffee -- is more complicated still. Certainly there is disagreement on this subject.

If it's a real issue one way to minimize it would be to freeze the coffee first and then vacuum seal it. That would mean that the boiling point pressures would be lower for each of the compounds. And there would be a lot less energy to vaporize the compounds. Ultimately energy is the limiting factor in vaporization. Pull a vacuum on that sponge and under the right conditions it would freeze.

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LBIespresso
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#7: Post by LBIespresso » replying to jpender »

Thank you for that explanation. Also, freeze, then vacuum seal is an interesting theory. It would be great to hear the people at Passenger, George Howell, and others discuss their green freezing practices.
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JohnB.
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#8: Post by JohnB. » replying to LBIespresso »

George Howell has posted lots of info about their green coffee freezing experience over the years. A few searches will still pull it up. Recently roasted a lb of El Salvador Los Luchadores Pacamara that I vacuum sealed with my "cheap Foodsaver" & froze back in 2011. Still smelled like fresh greens when I opened the bags, roasted normally & best of all is producing some very tasty Americanos.
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