The Joneses wrote:
> "Isabella Woodhouse" > wrote in message
> ...
>> I was just wondering if vinegar loses any of its acidity after it sits
>> (unopened) on the shelf awhile?
>>
>> Isabella
>>
> How old? How big an airspace, how many times opened (big jug = many times?)?
> I knew I should have checked something with that truly ancient cider
> vinegar before I tossed it last month. Joy of Pickling mentions that vinegar
> is more evaporative than water, so speaking from a layperson's point of
> view, I think it would depend on how truly ancient (the aforementioned was
> probably over 8 years old), how many times you'd opened it, and the general
> heat or something of the storage and kitchen used.
> I know I've had unopened gallon jugs of vinegar maintain their integrity
> for 3 years so far. That being a better quality commercial wine vinegar. No
> mother or anything.
> Overall, I'd increase the ratio of vinegar to water, if that applies, or
> just toss it and buy some more. 'Specially if it looks or tastes off. m2cw
> Edrena
>
>
The active part of vinegar is acetic acid, shouldn't lose strength at
all. The water added to get it down to 5% versus 20% or higher, might
evaporate if the jug is left open for a long period of time, otherwise
it should stay good damned near forever.