The Right Way to Dispose of Used Frying Oil—and How to Reuse It

Keep your drains safe by using these Test Kitchen–approved methods for proper cooking oil disposal.

Cooking oil used for delicious homemade fried chicken can pose a challenge when it's time to clean up. It's important to avoid pouring the oil down the drain, as this can lead to plumbing issues and environmental harm. Oils and fats can solidify, clog pipes, attract pests, and pollute waterways. To help you dispose of cooking oil safely and protect your home, here are effective methods approved by our Test Kitchen.

How to Dispose of Used Cooking Oil

After you've finished cooking with oil, allow it to cool to room temperature, then follow one of the three methods our Test Kitchen suggests for getting rid of all that used oil:

• Transfer cooking oil to a disposable container with a lid. This can be a cooking oil bottle, plastic milk jug or carton, coffee can, or a purchased grease disposal container. Seal the container and place in your household garbage. Note: Our Test Kitchen does not recommend using plastic bags, as they can easily spring a leak.
• Live close to a restaurant? Try contacting them about adding your oil to their collection bin, especially if you've got a large amount to dispose of—if, for instance, you're planning on deep-frying a turkey.
• If you're using soy, corn, coconut, olive, or sunflower oil (all of which are 100 percent vegetable oils) you can add any of them to your compost pile in small amounts (and we do emphasize small here, as too much oil in your compost could become a fire hazard). Earthworms will eat cooking oil. But be sure you're only doing this with vegetable oils. Animal fat is a big no-no for compost.

Test Kitchen Tip: You can also mix your used oil into cat litter. It will absorb the oil, making disposal easier.

How to Store Used Cooking Oil

If you're regularly deep-frying french fries, you can definitely help prevent food waste (and save money) by reusing your cooking oil. As long as the oil is clean and not full of food debris, you should be able to get another fry session or two out of it. Here's the best way to prepare and store used cooking oil for later:

1. When you're finished frying, turn off the heat and cool the oil completely to room temperature.
2. To remove any food particles, use a strainer lined with cheesecloth or a coffee filter.
3. Store the cooled, filtered cooking oil in a food-safe container, even the bottle it came in. You can streamline this process by purchasing a grease keeper. It's safe to keep used cooking oil in the fridge for up to one month.

Now that you know how to dispose of cooking oil properly, make sure you've got your frying basics covered. Use a deep-fry thermometer and you can be sure your fried fish, pork chops, fried ice cream, or anything else you want to deep-fry, is at the right temperature. And please note, if you're reusing your cooking oil, try to stay in the same food category, so the flavor profile remains the same. For example, you wouldn't want to make donuts in yesterday's fried chicken oil, unless you're planning to eat them together.