Vinegar is a fermented product and has an “almost indefinite” shelf life according to the Vinegar Institute as shared by Iowa State University Extension and Outreach. “Because of its acid nature, vinegar is self-preserving and does not need refrigeration. White distilled vinegar will remain virtually unchanged over an extended period of time. And while changes can be observed in other types of vinegars, such as color or the development of a haze or sediment, this is only an aesthetic change.
To maximize the shelf life of all vinegars, store them in a cool, dark cupboard away from direct heat or sunlight. Vinegar should only be stored in glass, plastic, or non-reactive containers. It is important that the lid is secured and replaced immediately after use to reduce the amount of oxygen coming in contact with the vinegar. The acidity of vinegar does not change unless moisture or water gets into the container.
Common and Harmless Changes in Vinegar
Cloudiness – Once opened and exposed to air, harmless “vinegar bacteria” may start to grow. This bacteria causes the vinegar to cloud. Cloudiness does not affect the quality of the vinegar or its flavor. Straining cloudy vinegar through a coffee filter may clear it.
Color – Red wine vinegar may become a pale red if sulfites are not added in the manufacturing processes. Other vinegars can change color. Residual sugars and amino acids in many fruit vinegars may cause a browning over time similar to the browning of baked food. This reaction is a long time (likely years) in coming. A change in color likely indicates a change in taste as well.
Sediment – Vinegars are usually filtered to make them clear. Those that are less filtered can form sediment over time as the particles settle. To deal with sediment, simply strain the vinegar through a coffee filter set inside a fine-mesh strainer before using.
Mother – Most vinegars are pasteurized unless stated otherwise. When pasteurization is incomplete or the vinegar is re-inoculated with vinegar bacteria from the air after opening, a slimy, amorphous blob or substance will form and float near the bottom. This is a vinegar mother and is just bacteria that feeds on alcoholic liquids. If one develops, it simply means that there were some sugars or alcohol that weren’t completely fermented in the vinegar process. Mother can be strained out using a coffee filter.
Any vinegar with 5% acidity is safe to use regardless of age for canning and pickling. However, non-white vinegars may lose flavor so for that reason, fresh vinegar may be advisable. Also, if any vinegar is showing any of the harmless changes mentioned, it would be best to not use the vinegar for canning or pickling since these changes may cause unwanted darkening, cloudiness, off flavor, or sediment in the product. Further, should there be any sign of condensation in the container or the container was left open for a period of time, the vinegar could possibly be less than 5% acidic and therefore, should not be used for canning or pickling.
Article release Monday, May 31, 2021
