Sorry but unless you buy some very expensive test strips they won't tell you a thing about the %acid. Litmus will only tell you if it is acid or not which your tounge can do better, let me give you the whole book on ACV. I grew up in a German orchard area in the north. the old germans would crush up several barrels with tops on of whole apples and stash them in the barn or basement.ORChick said:
They called this "juice" a refreshing drink for the whole family. within a few weeks the natural yeast in the 'bloom' of the apple skins would start to work and have bubbles in the liquid.
This was 'soft cider' suitable for kids women and men (not babies, the bubbles would cause colic)
When it got too strong for the kids to drink without getting drunk it was Hard Cider (about 8% alcohol) It would continue to work untill all the sugar was converted to alcohol (about 12-18% Alcohol like wine) where the yeast would die and they would decant off the liquids into fresh sealed kegs bottles or barrels.
This was the source of 'mild"alcohol untill the next fall Now if they wanted stronger stuff they would leave it Outside to freeze. the water froze out first and the remainder was Applejack a very strong and smooth drink indeed!
Now we get to ACV. That ice still contained a bunch of alcohol so they would move it to someplace warmer and thaw the ice Take the head off the barrel and replace with cheese cloth to keep the critters out and seed it with "mother" Stirr every day, you must have oxygen to convert alcohol to vinegar. and yes the alcohol was the limiting factor on the %acid produced and it often had to be diluted so it wasn't so darn sour.
I worked in a plant that produced white vinegar and ACV the difference was the starting feed, distilled grain alcohol for white, hard cider for Apple vinegar. by then they had bioreactors that would mix in the air and keep the temperature right as well as very pure starters. When the alcohol was converted, filter, and dilute to ajust to 5% acid heat treat and bottle,
