How Long Can You Store Sourdough Discard In The Fridge?
Sourdough discard, also known as sourdough surplus, is the extra bit of sourdough bread starter that you must remove from your sourdough starter before feeding it in order to prevent the starter from becoming too large. Like the starter it comes from, the discard imparts a deliciously tangy and savory flavor to baked goods; however, it does not possess the same leavening power. Just because it cannot make bread rise doesn't mean it isn't worth hanging onto though — there are a multitude of ways to use your sourdough discards, so be sure to store yours rather than throwing it into the trash.
Sourdough discard only lasts a day or two at room temperature. As such, it is best to keep your discard in the fridge, where it will last for up to one week. Of course, you can only rely on it lasting that long if you store it correctly. When readying your discard for the fridge, be sure it is sealed in an airtight container, such as a screw-top glass jar. This will prevent exposure to air and moisture as well as keep the discard from absorbing any strong odors that are present in your refrigerator.
How to tell if sourdough discard has spoiled
Even when refrigerated, sourdough discard will eventually go bad. It is important to always check your sourdough discard for signs of spoilage in order to prevent adding an unpleasant flavor to foods — or worse, consuming harmful pathogens. Be sure to examine your discard with your senses of sight and smell. If the discard shows spots of discoloration or visible mold growth or if it develops an excessively strong and unpleasant acidic smell, then it should be deemed expired and be thrown away.
If one week is not enough time to use all of the sourdough discard in your possession, it is possible to freeze the leftovers for later use. To do so, simply put the discard into a sealable container, like a zip-top bag, and place it in the freezer. There, it will last almost indefinitely until you thaw it. For this reason, it is best to portion out the discard into single-use amounts by separating it in an ice cube tray or into individual bags. This way, you can use what you need — whether you are making fresh sourdough pancakes or chewy sourdough chocolate chip cookies — while preserving the remainder for a long time.