I think once you get above about 4 percent alcohol level, almost all natural bacteria are killed.
The guys who made the barrels that held cider and scotch, etc, were not worried about keeping things totally squeaky clean!
Maybe my next project will be learning how to make barrels. I saw a show on PBS about it long ago. Very interesting, but how many barrels can you make before you had enough?
;-)
If that were true wine would not exist. Its 12%
you can inhibit bacterial growth at 4% but it will eventually find a way. 12% will generally halt any bacterial activity. incidentally, that’s why we have port today, because Portuguese wine merchants fortified their low wines with distilled spirits to preserve them on long voyages.