Re: homemade lobelia tincture - keep in fridge?
Generally speaking I would think that if it's kept out of light in the proverbial "cool dark place", ACV doesn't need to be refrigerated. If your room temperature is around 20 C / 67 F, that should be fine. There may be other factors that I am not aware of. The quality of the ACV may have an impact. . Schulze himself has said that real, live, raw ACV can't really go bad - "'cause it's already bad" :)
However, both he and Christopher have stated that specifically with Lobelia, it seems to be best tinctured with a combination of ACV & Alcohol. I've yet to find where either has said why this is, and I have yet to see where either have indicated what ratio of ACV to alcohol. Just going on a hunch, a 50/50 mix, meaning equal parts of 80 (to 100 proof) & ACV mixed together to form the menstrum. Also be aware, when you tincture, it can make a difference if you tincture fresh herb versus dried. Fresh herb will have a higher water content and this might require a bit stronger alcohol content.
As far as the film, I dunno, I suppose this could be the ACV mother. If this is the case, this is normal with good ACV, but again, after ACV has been turned into a tincture, I don't know if it's still normal for the mother to keep living or not.