Expiration & Storage Tips
When does kefir expire?
After purchase, unopened kefir typically lasts for about one to two weeks beyond the 'sell by' date marked on the package at room temperature, provided it's been stored properly. Once it's opened, kefir is best used within one week, or it will begin to sour and ferment further. If you've frozen kefir (which isn't a common practice given the changes in texture it can result in), use it within a month for best quality.
How do you tell if kefir is bad?
Spoiled kefir has a strongly sour smell, even more so than the typically tangy aroma of a fresh batch. The texture can also change, becoming excessively thick or even lumpy. In addition, there may be visible mould on the surface. If you see or smell any of these signs of spoilage, it’s best to play it safe and discard the kefir.
Tips for storing kefir to extend shelf life
• Always refrigerate kefir to keep it fresh for longer. It should be stored at temperatures below 40 degrees Fahrenheit.
• Keep the kefir bottle tightly sealed when not in use to prevent it from absorbing other strong odors in the refrigerator.
• Use a clean spoon or pouring method to serve kefir. Putting your mouth directly on the bottle or introducing bacteria from used utensils can cause the kefir to spoil faster.
• If you decide to freeze kefir, make sure to leave enough headspace in the container for the kefir to expand. Keep in mind that the texture might change and become grainy once defrosted, so it's best used in cooking or blending.