posted 2 years ago
Heather is correct, with her questions about the storage conditions. Cold is rarely an issue, but too hot can quickly deteriorate the glycerine, and more slowly, the vinegar based ones.
Personally, I'd use the alcohol ones without hesitation, for years yet to come. The vinegar ones, I'd try to use within the next year, and the glycerine ones, within the next six months, a long as there are no 'off' smells, colors, or films on top. The advantage to being in storage all this time, is two-fold: 1 - they've been unopened, so no exposure to contaminants, or oxidation, and 2 - that it's probably safe to guess they were all in the dark. The light will destroy them faster than mildly-to-moderately fluctuating temperatures, and just as quickly as extended, high temperatures.
"The only thing...more expensive than education is ignorance."~Ben Franklin
"We can easily forgive a child who is afraid of the dark; the real tragedy of life is when men are afraid of the light." ~ Plato