ordering larger amounts of roeasted beans I freeze most of them for the rest of the month. Making bags with two to three days worth after they have reached their prime point.

Now i am using good quality vacuum bags but a cheapo vacuum sealer and I wonder if anyone has the same behaviour of the vacuumed bags. Before I go out and buy one of the likely good quality vacuum machines like a foodsaver I'd like to know if more folks have observed that the bags stay quite loose...

It could be the CO2 in the beans coming out or just the poor seal/vacuum (tend to double seal the bags)...?

Personally, especially for freezing coffee, I like canning jars (Ball) better.

And you don't vacuum those I guess?

Can you tell me why you like those better? (Have plenty of those around as We store our vast collection of herbs and spices in those)

I tried the Ziploc vacuum bags with the one-way vent and little hand pump (are those cheapo bags?) and believe I was having problems with poor seals. I only single bagged. They weren't that cheap and the label says they are to be used only once. The packages would always lose their tightness, and that could have been due to a bad seal or to CO2 out-gassing - no way to tell. Some that had been frozen a good while smelled and tasted off to me.

I've gone to 8oz ball jars since and like them much better. Once I had one jar in a batch taste off, and I think that one may have had an old lid with a poor seal. Things I like about them:

• They hold about 180g of my favorite beans - appx 10 doubles which lasts me 2 - 5 days. I can have two or three different beans on the counter and use them up within a week or two.
• They make this satisfying 'ping' sound after they're taken out of the freezer and left on the counter to thaw. Lets me know the seal was good.
• I put labels inside the jar against the glass (on postit notes) that are always easy to read.
• The jars can be re-used forever. I replace the lid after a year or so (I write date on lid underside with a marker.)
• During use, I just leave them in the jar on the counter with the lid tight.
• I can purge the jars of O2 before freezing them if I want.*

* I can do this using my wine preserver, but what I do nowadays is jar up freshly roasted beans and let them sit still a day on the counter with the lid loose. CO2 is heavier than O2, so in a very still space the outgassing of CO2 should settle to the bottom and dispel air from the loose lid.* I have no idea if this makes an actual difference but to me it makes sense and can't hurt.

*Edit correction: O2 may be a little lower due to purging by CO2 outgassing, but in practice even in a still container there would be no stratification of the gasses. See Carpenter and Fox, Absence of Stratification and Rapidity of Mixing of Carbon Dioxide in Air Samples.

Thansk for explaining!
Also tried ziplock bags and for those only the most expensive seem to hold their water

Also makes sense what you do with co2 letting the outgassing take place in the jar, next batch I'll give it a go and see, don't think the difference will be huge but convenience goes a long way and vacuum sealing is a bit of a pain.

I've been vac sealing roasted coffee for years using a Foodsaver & the bags stay nice & tightly packed for months as long as you get a good seal initially. I also have the Foodsaver widemouth jar sealing attachment & vac seal the canning jars when I freeze coffee in them. As long as you are storing the bags in a freezer that maintains a temp of 0°F or lower you shouldn't see any degassing in the bags until they are out on the counter.

Thanks for that, I think it is the vac machine that's crappy.
Not sure what 0 F exactly is in C is but my freezer easily keeps it's -20 CWhich should be more than'nuff (too lazy to look it up right now)

Think I'll try the jars for a bit, if that takes up too much room I'll buy me a decent vac machine.

Marcelnl wrote:Before I go out and buy one of the likely good quality vacuum machines like a foodsaver I'd like to know if more folks have observed that the bags stay quite loose...

The Foodsavers (at least a lot of them) allow you to vacuum seal in bags OR in mason jars.
http://www.amazon.com/FoodSaver-T03-002 ... B00005TN7H

This jar sealer attachment also comes for regular Mason jars, but I've encountered more failures than with the wide mouth one.

cmin wrote:Personally, especially for freezing coffee, I like canning jars (Ball) better.

+1, 8 oz canning jars work great for roasted coffee.

Marcelnl wrote: Not sure what 0 F exactly is in C is but my freezer easily keeps it's -20 CWhich should be more than'nuff (too lazy to look it up right now)

-20°C = -4°F which is plenty cold enough to stop degassing & dramatically slow aging.