Red Wine Vinegar in a glass cruet.  The image is shown as an angle and is in full focus from front to back. Vinegar can be used as a condiment or as an ingredient in cooking recipes.  It is a liquid consisting mainly of acetic acid.
Food - Drink
The Real Reason Ina Garten Stores Vinegar In The Fridge
By AUTUMN SWIERS
Celebrity chef and television personality Ina Garten reportedly keeps her kitchen stocked with many kinds of vinegar, including red, white, apple cider, balsamic, and champagne vinegar. However, the way she stores vinegar might surprise you: Garten keeps her bottles in the refrigerator, not in the pantry.
"I might take hell for this," Garten admits, "but I just find that they don't develop bacteria in the fridge." The celeb chef really shouldn't be criticized; all vinegars do contain acetic acid, which gives each bottle a long shelf life and makes it okay to store them in the pantry, but sometimes the fridge really is the best.
Give your vinegar a taste to determine where it should be stored. If the flavor is super acidic, go ahead and pop the bottle in the cabinet, but less acidic vinegars do not keep as well, and should be refrigerated to maintain their flavor. Also, most types of vinegar are safe to use past the expiration date on the bottle.
Distilled white vinegar has the highest acidity at around 5-10%; red wine, white wine, and balsamic vinegars have 6-7%; and malt, cider, and rice have around 4-5%. Also, if your vinegar is "raw" or untreated, don't worry about floaters in the bottle; this is simply good bacteria and a byproduct of fermentation.