I had mentioned in passing that I ran out of vanilla to my mother and she gave me the vanilla she had gotten from my ex-SIL when she moved. There no longer is a label on the bottle, it's completely discolored the plastic bottle (was a gallon of Vanilla) about a quart left. I know this vanilla has to be over 10 years old. Is it still safe to use?
P.S. It still smells like vanilla
If in doubt, throw it out.
My grandma still uses extracts and certain flavorings that used to belong to my grandma (that has to be about 8 years now) so I am guessing that it has to be safe.
I would want to know the source. I used to get vanilla from Mexico when I lived in Arizona...in large containers, very inexpensive. Then I started learning more about the cheap Mexican vanilla which was often adulterated with tonka bean extract. Tonka beans are cheap and have a vanilla flavor, so they were used to extend the more expensive vanilla. However, they contain coumadin-a powerful blood thinner. I stopped bringing it home with me at that point. This was over 12 years ago and I believe, now, to be sold in the US, it has to be coumadin-free. I have since purchased bottles of Mexican vanilla here and do find the label to attest to that fact. If it was obtained here and you were sure, I would use it. It does discolor plastic but the high alcohol content of an extract should leave it OK.
I googled 'shelf life of imitation vanilla' (I'm guessing it's imitation since it is in a gallon bottle, my apologies if my assumption is wrong). Anyway, this is what came up with this:
From About.com -
Beans should be kept in a tightly-closed container in a refrigerated area where they should last up to six months. Pure vanilla extract has an indefinite shelf-life, and actually improves with age. Vanilla powder is also available, which should also be kept tightly-sealed, in a cool, dry place away from sun and heat. Whole beans that have been used in sauces or other liquids can be rinsed, thoroughly dried, and stored for reuse.
Here is the link if you want to check it out: http://homecooking.about.com/cs/foodfactsheets/p/vanilla_pro.htm
From WikiAnswers -
"The folks at Nielsen-Massey Vanillas (whose goal, admittedly, is to sell more and more vanilla) say you can keep properly stored vanilla extract for four or five years. Proper storage, they add, implies a tight seal and room temperature. "
From Durkee -
It is talking about clear imitation vanilla but I'm guessing it's probably the same for regular imitation vanilla.
"This product is packaged in quart and gallon sized clear recyclable plastic bottles with tamper evident foil-lined inner seals. The quart bottles also have a pour spout lid for ease of measuring. For best results, store tightly closed in a cool dry place.
Shelf Life: 3 YEARS"
edited for content