A caller asked me if she could compost the used oil after deep-frying a turkey. It was a good question, because what does one do with all that used oil? Before answering the question, let's talk about what compost is.
On compostguide.com., it is defined as "the end product of a complex feeding patter involving hundreds of different organisms including bacteria, fungi, worms, and insects."
Composting requires green vegetative material as a nitrogen source, dried plant matter to supply carbon and some soil, water, air and microorganisms. Mixing all the ingredients in the right proportion produces a rich, crumbly end product called humus.
Composting is a great way to recycle leaves, stems and clippings from the yard. Vegetable refuse from the house, including vegetable peelings, melon rinds, fruit skins and cores, and houseplant trimmings can also be composted. Tea bags and coffee grounds and filters are excellent additions to the compost pile.
Although meat and fish products can be composted, they break down very slowly. They smell bad and can attract a number of pests, including coyotes, dogs, cats, skunks, bears and rodents. Meat and fish bits can contaminate the compost pile with disease organisms. For these reasons, avoid composting all bones, fats, greases and oils, including the oil used to fry the turkey.
There are additional reasons to refrain from composting oil. Many gardeners are aware of horticulture oil sprays used to suffocate overwintering insect eggs and adults. Although cooking oil is not the same formulation as horticulture oils, it would produce the same result in the compost pile, smothering the organisms needed to break down vegetative matter into humus.
Oil would also fill up pore spaces in the developing compost, squeezing out air and moisture. This would create a foul-smelling situation!
Oil for deep-frying can usually be reused. The USDA says to let it cool, strain it, pour it into containers for the refrigerator, cover the containers, and use the oil or dispose of it within one month.
Or if you don't want to reuse it, simply put it in a plastic container that seals and put it in the trash. You may also be able to work with a local restaurant to recycle your oil with theirs. Do not dump oil down the drain, where it can clog the drain and eventually cause problems at sewage treatment plants.
Perhaps one day, all cooking oil will be turned into biodiesel fuels for our cars, freeing us from relying on foreign oil!
For more information, e-mail skellyj@unce.unr.edu or call me at 887-2252. You can "Ask a Master Gardener" by e-mailing mastergardeners@unce.unr.edu or call your local University of Nevada Cooperative Extension office. Check out many useful horticulture publications at www.unce.unr.edu.
• JoAnne Skelly is the Carson City/Storey County Extension educator for University of Nevada Cooperative Extension.