Does vinager expire??

I have a gallon og vinegar I found in the pantry.. I was born in 95 and the expiration date on the bottle is : 4-7-96!!!!!!!whoa..lol...I am tryin to do science fair project on pennies with it.. It doesnt seem to work.. Does vinager ever ever expire or go bad? i kno the taste and stuf would..but the effect?