How to Dispose of Grease and Cooking Oil

fried potatoes
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The downside of using cooking oils to fry foods at home is dealing with the greasy mess left over afterwards. Some foods, such as bacon, leave behind a lot of their own grease, which also needs to be dealt with. Instead of just pouring used grease down the drain, recycle it by using it again, or by offering it to a facility that recycles kitchen oils. In some cases, disposing it in a sealed container in the trash is also acceptable.

Stay Away from the Sink

While it may be tempting to throw used cooking oil down the drain, this is a bad idea. Grease and cooking oils coat the insides of the pipes, causing a gunky, thick buildup that could cause clogs that are difficult to thoroughly remove. Don't throw cooking oil down the toilet, either, as the grease still ends up in the sewer system. These oils can cause clogs, resulting in sewage backups or overflows into waterways, harming the environment.

To help keep as much residue out of the drains as possible, wipe any greasy dish, pot or pan off with paper towels and discard those in the trash before placing the cookware in the sink. Wait until pots and pans are cool before wiping them off and before placing them in a sink full of water.

Local Recycling Options

Group of rows of green stacked biofuel drums in storage warehouse
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Cooking oil can be recycled and transformed into biodiesel fuel.

Some communities accept used cooking oils and greases in their recycling programs, which is then transformed into biodiesel fuel. Call your local recycling and waste-disposal company to determine if cooking oils are accepted, or check your community website page for recycling information. If unable to find a place to recycle that oil, search on a site such as Earth911 for the nearest local facility that accepts it. Some community recycling programs only accept cooking oils from residents living within a defined region, so be sure to read the details before visiting the listed recycling center.

Reuse Relatively Clean Oil

Deep fryer.
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Cooking oil can be reused for frying foods.

If you regularly have waste cooking oil after your kitchen adventures, save the leftovers for future use. Wait until the oil cools, then pour it into a container such as an empty vegetable oil bottle. Filter the debris out first by placing a coffee filter into a funnel, then placing the bottom end of the funnel into the bottle. Pour the cooled oil in the bottle, then label the bottle to identify the type of grease and the date it was first used. Store the closed container in a cool location.

Oil can generally be used several times before it imparts a bad taste to other foods. Be sure to use the oil for a similar cooking project to avoid errant flavors in the new dish. For instance, oil used to fry fish shouldn't be reused to make fried chicken. Before reusing the oil, sniff it to ensure it still smells good. If it smells rancid or has a waxy odor unlike cooking oil, it should not be reused.

Time for the Trash

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Cooking oil can be thrown away in household trash

If throwing out that used oil is your only option, place the used oil in a sealable container, then toss the container once it's full. Coffee cans and juice containers with lids are ideal for grease storage. If cooking with a grease that hardens a bit, such as bacon grease or lard, you can also store the grease in disposable coffee cups, keeping the cups in the freezer to harden the grease even more. Dispose of the container in your regular trash, within a sealed bag. Do not place used oils in a compost pile or bin, as the oils can harm plants, animals and the soil over time. The oils also may affect the ability of organic matter to decompose in the compost heap.