How Long Is it Safe to Keep Used Vegetable Oil?

By Cassie Damewood

Some culinary functions, like deep-frying, require large amounts of vegetable cooking oil. Since the oil is often used to prepare only one dish, it may seem wasteful to simply discard it. Vegetable oil is safe to use numerous times if properly handled and stored.

Potatoes are cooked in oil to make French fries.

Basic Oil Care

After the frying is complete, let the oil cool to room temperature. Line a mesh strainer with cheesecloth, layers of paper towels or a coffee filter and strain the used oil through it to remove food particles, crumbs and impurities. This process is safe to repeat after three or four frying sessions without the oil deteriorating.

Strong Flavor Removal

If strongly flavored foods have infused the oil with distinctive tastes, fry some pieces of raw potato or citrus fruit in it prior to filtering to remove the errant flavors.

Storing Used Oil

Used oil can be successfully stored in a cool, dark place for up to a month. Refrigeration or freezing increases the oil's lifespan by several months. The oil may become cloudy during storage but this is not harmful and the oil will become clear upon reheating.