Not sure if this is the correct forum for this, but this is where the true bean-heads hang out, so I thought I'd give it a try.

I ordered a foodsaver vacuum packer with a mason jar adapter, with the thought of vacuum packing freshly roasted beans in 1/2 pint or 1 pint mason jars before freezing them. The thought was that by removing the air the oxidation that causes the oils to break down would be slowed.

But then I read that the crema is a result of trapped CO2 that is released during the pull, and now I am wondering if storing the beans under vacuum would actually kill them sooner!

Putting aside the debate about freezing versus not freezing, is vacuum packing a good thing or a bad thing?

CoffeeBuzz wrote:Not sure if this is the correct forum for this, but this is where the true bean-heads hang out, so I thought I'd give it a try.

I ordered a foodsaver vacuum packer with a mason jar adapter, with the thought of vacuum packing freshly roasted beans in 1/2 pint or 1 pint mason jars before freezing them. The thought was that by removing the air the oxidation that causes the oils to break down would be slowed.

But then I read that the crema is a result of trapped CO2 that is released during the pull, and now I am wondering if storing the beans under vacuum would actually kill them sooner!

Putting aside the debate about freezing versus not freezing, is vacuum packing a good thing or a bad thing?

If the coffee is fresh you just can't do it because the coffee outgasses so much. Successfully vacuum packed coffee, like you see in the supermarket is stale by anyone's definition here. Better to put the fresh coffee directly in the mason jar, and store it in the freezer if you do not plan on using it in the next couple of days. I think the freezing debate has been more or less resolved in favor of freezing. There's very good information on this site wrt freezing that should be helpful to you.

-Greg

I've not tried it in Mason jars, but I often use the bags to vacuum pack coffee right out of the roaster and then freeze it. It does outgas, but very slowly, and I've never had a bag pop. I find it particularly useful as a way of keeping decaf, which as you know stales very quickly, around for when people come over and want some after dinner.

Best,
David

Anyone know what the composition of the outgas is?

At the risk of sounding ignorant, here is why I am curious.

Consider what might happen if you vacuum pack freshly roased beans in a mason jar. The process of vacuum packing will remove a significant amount of the oxygen from the bottle, which will slow the degredation (normally attributed to oxidation) of the oils and other good stuff in the beans.

The beans will then outgas, negating the vacuum and possibly creating a positive pressure inside the jar.

If the gas is composed of something 'good' for the beans, e.g. carbon dioxide , then storing them thusly would be beneficial. This is based on the assumptions that (1) CO2 trapped inside the beans is responsible for generating the crema, and (2) storing beans in a CO2 pressurized environment would lenghten the time the beans are capable of producing crema. Of course, both of these assumptions are merely, um, assumptions.

However, if the outgas consists of things that are 'bad' for the beans, then sealing them before outgasing has run its course wouldn't be such a good idea.

I don't know enough to provide a detailed explanation, but what was told to me is to immediately put your cooled home roasted beans out of the roaster, into sealed mason jars and into the freezer. This supposedly prevents the beans from maturing/outgassing - you can't wait a day or two before freezing.

Then I will pull them out the usual time length before I want to use them (2-4 days) for them to outgas.

All I can say is that when I do this, I can tell NO difference at all compared to never frozen, and I could not say that about beans that were frozen after outgassing had begun.

CoffeeBuzz wrote:Anyone know what the composition of the outgas is?

It's CO2, according to Illy & Vianni.

Best,
David

I've been experimenting with the Reynolds Vacuum bags (and the pump that you use with them). I split my coffee's in half and put it in the bags, pull a vacuum and store in the freezer. Seems to work fine (but I don't leave them in the freezer long! ). While I don't "home roast" (at least not yet!) and I don't leave them in the freezer more than a few weeks, the frozen beans seem to retain most if not all of their freshness until I use them up! I use a "Sharpie" pen to write the roast date and the type of coffee (i.e. CCC Gayo or Mill Mountain Costa Rican, etc). That way I can have enough beans for a few days in the grinder and swap out to a different blend (or SO) for the NEXT few days! Been working FINE so far!