Frogleg wrote:

What *does* the "5% acidity" label on a bottle of kitchen
vinegar mean anyhow? 5% the strength of pure hydrochloric
acid?

It is the strength of 5% acetic acid. Pure white vinegar is basically acetic
acid and water. With the other versions there are numerous other compounds
that give them their distinctive character.

More info than you may really want to know at:
http://www.foodsubs.com/Vinegars.html

--
Pete Romfh, Telecom Geek & Amateur Gourmet.
promfh at Texas dot net