Can you compost vegetable oil? (9 Types)

In this brief guide, we will answer the question, can you compost vegetable oil? We will discuss the types of oils that are safe to be composted and the cautions you need to take if you want to compost vegetable oil.

Can you compost vegetable oil?

You can compost vegetable oil. Make sure to add plant-based vegetable oil that has not come in contact with meat. If you used vegetable oil to prepare any meat by frying or sauteing then you must not use it as compost. 

You can add only tiny amounts of vegetable oil to a compost heap. If you add too much oil, it causes poor circulation of air and creates a bad odor, harboring bacteria and attracting rodents and insects. 

Moreover, the vegetable oil is hard for the compost to break down comparatively with the other ingredients. 

The EPA or the United States Environmental Protection Agency advises against adding oils to your compost heap. With that said, if you decide to add oil to it anyways, there are a few things you will need to watch out for.

What are some things to keep in mind before you put vegetable oil into your compost pile?

The average vegetable oil that you can add to your compost heap is half a cup. However, it mainly depends on the quantity of your compost heap. 

Vegetable oil is harder for the soil to break down, hence it is not recommended that you add vegetable oil. 

The vegetable oil that you add to your compost heap, should be spread evenly. If the oil accumulates on one point of the compost heap only, it tends to create problems. You also need to make sure to toss and turn the pile to allow air to mix and reach everywhere. 

The oily barrier created causes anaerobic conditions due to the absence of airflow. The microorganisms and critters need oxygen to successfully decompose your compost heap. 

As the bacteria accumulate and air does not circulate, it encourages an off-odor to form and consequently affects your compost heap in a bad way. 

Another thing you could do to ensure that the oils decompose quickly is to make them hot. If you make it hot, it discourages the formation of odor and wards off insects and rodents. 

When you provide a temperature of 105 to 140 Fahrenheit, it encourages the growth of thermophilic bacteria. The thermophilic bacteria thrive in hot weather and are efficient decomposers of compost heaps. 

What oils can you add to the compost?

Plant-based oils are a good option to add to the compost heap. Corn oil, canola oil, coconut oil, olive oil, grapeseed oil, soy oil, sunflower oil, rapeseed oil, and vegetable oil are all either plant-based oils or derived from them. 

You can not add any of the above oils that have been used or have made direct contact with meat, poultry, or seafood. 

Make sure to avoid adding synthetic oils, gravy, lard, bacon grease, leftover sauces, and juices that you cook. Adding any of the above oils could wreak havoc and create a mess for your compost. 

If you have a worm bin, you can add vegetable oil without any worry. The vermicompost has worms that break down the oil without difficulty. Also, add paper towels that may have oil in them. 

How to manage oil?

You can manage oil to make sure none of it gets wasted. Oil can be turned in to your local council to recycle. It can also be used to make bird feeders with solid oils. 

However, never pour oil down your sink or drain as it can cause it to clog and create trouble for you. 

You must not throw the oil outside either because it makes its way to sewerage pipes and causes problems.

Follow the rule, reduce, reuse and recycle to make most of your oils. To reduce your oil usage, use a cooking method that does not need oil such as baking and steaming. Resort to spraying oil instead of pouring it and use non-stick pans that need minimal oil to cook. 

It is safe to use oil for cooking another time. Make sure not to heat the oil past its smoke point and store it carefully in an airtight jar. 

You could even donate it to be used as a biofuel. Earth 911 is a company that would take vegetable oil and use it to make fuel. 


In this brief guide, we answered the question, can you compost vegetable oil? We discussed the types of oils that are safe to be composted and the cautions you need to take if you want to compost vegetable oil.


Hi, I am Charlotte, I love cooking and in my previous life, I was a chef. I bring some of my experience to the recipes on this hub and answer your food questions.