Flavored buttermilk can often be stored for 2 days without significant separation, but it depends on the ingredients used for flavoring and the storage conditions. Some separation is normal, but excessive separation indicates spoilage.
Buttermilk, by its nature, is prone to some separation. The addition of flavorings can either exacerbate or mitigate this. For example, acidic fruit purees might cause more separation, while stabilizers in commercial flavorings might reduce it. To minimize separation and ensure safety, follow these steps:
Use Fresh Buttermilk: Start with the freshest buttermilk possible. Check the expiration date and ensure it smells and looks normal.
Incorporate Flavorings Properly: Mix flavorings thoroughly and gently. Avoid over-mixing, which can break down the buttermilk's structure.
Store Properly: Store the flavored buttermilk in an airtight container in the refrigerator at a consistent temperature (ideally below 40°F or 4°C).
Observe and Smell: Before using the stored buttermilk, check for excessive separation, unusual odors, or changes in color. A slight separation is normal and can be remedied by stirring. If it smells sour or off, discard it.
If you're concerned about separation, consider adding a small amount of a stabilizer like cornstarch (a tiny pinch, bloomed in cold water first) or gelatin (also bloomed) to the flavored buttermilk. This can help maintain a smoother consistency during storage.