No problem. Sorry I came off so hot. I have this forum curmudgeon thing going on, ha ha.
No problemo. I get it. Also, who the fuck am I and what do I know? Hahaha.
OK. So here's my understanding.
First of all, Mason jar snap lids are not 100% air tight because the seals are made of silicone and "
silicone rubber is one of the most permeable elastomers." So there's going to be some exchange of gasses through that thin bit of silicone. It's inevitable. The same thing is happening with flat style tobacco tins. My sister-in-law makes naturally fermented beets in Mason jars. Ingredients: Beets, Water, Salt. The lids "seal" themselves as the vegetables ferment because the ring holds the snap lid in place and escaping gasses (CO2) leave a negative pressure environment inside the jar, which pulls the lid down and holds it in place. Eventually, you can remove the ring and invert the jar and the lid stays in place. No heat processing involved.
Snap lids are supposed to be heat-processed according to the manufacturer because it (I guess) softens the silicone. More importantly the internal heat forces gas out from the jar and the pressure differential is much higher than what you get if you don't heat-process. Thus a much better seal. When I started jarring tobaccos I heat-processed my jars by placing the tobacco in the jar with the lid off, placing the jars in simmering water for a minute, then removing the jar and placing the lid on it. This resulted in a good seal once the jar cooled. The lids would pop down...
But wait a minute...
These other jars that I never bothered heat-processing seem to
seal themselves after a couple of months sitting in a drawer in the basement. WTF? Obviously there's a negative pressure environment inside the jar. It seems like gas is escaping faster than it's getting in. This makes sense to me. After all, Mike McNeil over on
this youtube video [starting around the 7:30 mark] talks about how tobacco continues fermenting after canning. I guess what's happening is the tobacco in the Mason jars is off-gassing and the unsealed lids are allowing gas to escape, just like my sister-in-law's beets. Makes sense to
me. But then this wizened and very erudite and esteemed forum member over here says, "There is no gas to escape from a jar", and I'm like, WTF? That goes against everything I know and understand about tobacco and fermentation. If there's no gas being produced by fermenting tobacco, why are all these tins gradually inflating in my basement?
Now, obviously different producers use different methods and different additives, and it's all covered in trade secrets so who the hell knows what really goes into those tins. Does PG sterilize tobacco? Are the leaves exposed to sterilizing UV rays or space lasers?
But tobacco is a fermented product, and in at least some cases, fermentation definitely seems to continue inside the tin — and inside my canning jars — which means gas is being produced, MOST LIKELY by some extant lactic acid producing bacteria. Do I KNOW this to be the case? NO. You asked why I think there would be lactic acid in tobacco. Because lactobacillus are "
found in every soil and on every leaf surface." That's why I asked if tobacco producers use sulfates or some way of sterilizing the tobacco before canning. I assume not, but I don't know. I would guess flue curing would kill some (but probably not all) lactobacillus. Air cured leaves would still be covered in dormant cells. "
Lactobacilli are inactivated by UV, microwave, gamma radiation, moist heat (121°C for at least 20 min) and dry heat (165-170°C for 2 h)" Is flue cured tobacco exposed to 121ºC wet heat for 20 minutes? I don't think so. But I don't KNOW.
Also, just as an addendum, I've been making beer, mead, and wine for over 25 years, so I know a fair bit about that topic (though I'm not an "expert"). There are lots of great wines that have added sulfites. Most commercial wine has sufites added. I've produced wine and mead with and without. Some GREAT mead if I do say so myself — and no — adding sulfites doesn't turn otherwise good product into "the McDonalds of wines." It just protects it from spoilage. I've opted for not using sulfites and had mead sit on the shelf for over 5 years without spoiling, so it's probably not necessary, but in small amounts it doesn't have (much) effect on flavour IMO. YMMV.