But when preserving food in a hot process, the seal melts and forms to the jar. That is why lids are single use. I don’t think using the jars is a bad idea, but I do think bags are better.
agreed, but is it any better or worse than a bag?
jeff - the lids are on tighter than when I have used the in actual canning. i don’t think you will get O2 in via the lid, that is for sure.
Well, not sure. But bags provide the same quality vacuum with a smaller volume of air. As long as they are oxygen barriers, bags would be better.
One would think that O2 does not get into a beer bottle, but it does. The partial pressure of O2 is the driving potential. The cap material has permeability, so it gets in, as the bottle can have very low O2 levels, and the atmosphere has 21% O2. This is why Sierra Nevada went to the pry off caps, a new low permeability liner required high clamping loads than a twist off could provide.
I like to spend time lounging in the freezer on a hot summer day and drink a cold one after mowing the lawn 
My vote is for bags. I buy them in bulk for very cheap and will get multiple seals out of them assuming I don’t have a particular powdery hop that coats the inside of the bag. I just can’t believe you get the same amount of air out of the jar as you do from the bags. I just see headspace in the jar and I know it’s not a perfect vacuum and there must be o2 present.
Here’s an experimental for someone. Half and peel an avocado. Vacuum seal one half in a jar, vacuum seal the oher half in a food saver bag. Put both in the fridge. The first one to turn brown looses.
Good idea, but a waste of an avocado. 
How about an apple?
Or a cat?
I’m kidding, don’t hate me. Some of my best friends have been cats
Are cats a good, quick indicator of oxidation?
Don’t get me wrong, I just can’t imagine why you’d waste a perfectly good avocado.
Lately I’ve been on this kick of my afternoon snack consisting of a Costco (remarkably consistent) avocado, halved, sliced, sea salted, fresh ground peppered and a drop of SriRacha on each slice. All I’m sayin is give it a shot if you dig avocados. To eat that is.
Love em! Can’t make my California rolls without em. But, I think if you’re guessing that one method might oxidize an avocado, well what’s it doing to hops?
My avocado tree is in full bloom right now. It looks like a bumper crop this year.
Try Tabasco and/or a fresh squeeze of lime, lemon or even rice vinegar. Sublime. I like the small avocados since they are better as a single serving. They ripen quicker and more consistently. That way I can eat a whole one without any feeling of guilt.
#^#@!% Floridians ;)… the taps have been in our sugar maple trees for 3 weeks already but nothing’s dripping as the temperature steadfastly refuses to rise above freezing for more than about 30 minutes a day… but there’s still 2 feet of snow on the ground so when the thaw finally comes that should help with a good run…
(sorry… off topic but I’m particularly cold this morning!)
Hopefully this weekend looks like it will be warmer.
Except avocados and apples are browned by enzymatic reactions
Atrocious!
The enzymes facilitate the oxidation of iron/other compounds in the fruit.