It’s added to so many foods today and comes in various types: peanut oil, sunflower oil, shortening, etc. Can you compost cooking oil?
We have seen several animal products that are technically compostable, especially in a closed system or a commercial compost set-up. We can not add cooking oil to that list.
It is technically compostable. It will eventually break down, but mice, rats, raccoons, and any number of other pests are attracted by the smell of cooking oil and grease. This will lead them to rip into your compost pile, eat the food there, and then have a stinky pile of leaves. Not good.
So for that reason, we recommend against adding cooking oil to your compost.
How to Compost Cooking Oil
If you are going to try to compost it, you can only compost natural cooking oils (no synthetics) such as
- Sunflower Oil
- Vegetable Oil
- Olive Oil
- Coconut Oil
- Rapeseed Oil
- Peanut Oil
Do not try to compost oils that have been used for cooking meat.
If you add larger amounts, the oil can coat other substances making them more difficult for the microbes to compost. The warmer your pile, the more cooking oil you can “safely” compost. You can probably start with a cup of oil for smaller, healthier piles.
Can You Compost Cooking Oil in a Worm Bin
Do not add any cooking oils or grease to a worm bin for a few reasons.
- It can make it more difficult for the worms to breathe. No seriously. Worms breathe through their skin. If you coat their skin with oil, they have a harder time breathing (and they may call you nasty names.)
- The oil tends to go rancid fairly quickly. This puts off the worms, and they won’t eat it.
For these reasons, it’s a good idea even to rinse off oily foods before adding them to your worm bin.
Frequently Asked Questions for Adding Cooking Oil to Compost
Can You Add Grease to Compost?
Unfortunately, not for all the same reasons. Mice and rats don’t care about their cholesterol and will tear into a compost pile with grease in it.
Can You Add Bacon Grease to Compost?
Same answer here. Bacon is good and mice know it too. Remember that smell when mom would make bacon in the morning? That same smell is like a beacon for rodents and other pests to your compost pile.