I recently received my order of propylene glycol for experimental purposes. I emptied out all the vodka (mostly water after a few weeks) and refilled with PG. No problems so far. It is quite liquid, somewhat viscous, feels nice when I dribble some on my skin (it's used for this purpose in a LOT of products), tastes slightly sweet, but with a little bit of a burning sensation on my tongue that rapidly gives way to a pleasant warmth as it dissolves with my saliva. I cannot use my old syringe needles with it, and need to use at least a 15 gauge needle to pull it into the syringe quickly. It has no appreciable smell or taste (other than some sweetness) to it. And as far as I can tell it has no drawbacks to date. It is hygroscopic (it attracts and holds onto water molecules), and miscible (mixes in all proportions) in water, acetone and chloroform. We won't worry about the last two items though... It is a bacteriostatic agent that will not allow the bacteria to multiply, but will not kill them either.
It allows the air bubbles to freely flow in both directions. I would NOT use this for an active ferment as it would probably be forced out of the airlock as it is somewhat viscous and would not have the time to slide back down before the next bubble(s) send it up and out. Probably best as a long term bulk aging airlock filler rather than as an active ferment airlock filler.
I filled my airlocks with it, and have a piece of gauze held in place with a silicone band (rubber band but made from silicone) to keep dirt, dust, and insects out of my airlocks. So far one week out and no problems, other than a few pesky airlocks not sealing because of the airlocks rough edges. I filed them down, then flamed them lightly to smooth out all the surfaces and make a better seal with the drilled stopper.
I'll keep an eye on my experiments and report back once in a while, or when people ask.
It allows the air bubbles to freely flow in both directions. I would NOT use this for an active ferment as it would probably be forced out of the airlock as it is somewhat viscous and would not have the time to slide back down before the next bubble(s) send it up and out. Probably best as a long term bulk aging airlock filler rather than as an active ferment airlock filler.
I filled my airlocks with it, and have a piece of gauze held in place with a silicone band (rubber band but made from silicone) to keep dirt, dust, and insects out of my airlocks. So far one week out and no problems, other than a few pesky airlocks not sealing because of the airlocks rough edges. I filed them down, then flamed them lightly to smooth out all the surfaces and make a better seal with the drilled stopper.
I'll keep an eye on my experiments and report back once in a while, or when people ask.