How to Recycle Used Cooking Oils

Using cooking oil only once is a waste of resources and can be damaging to the environment. Instead, one should recycle the oil by reusing it in the kitchen, donating it, or finding recycling center that accepts it.

By Maryruth Belsey-Priebe

Fact checked by Sander Tamm

How to Recycle Used Cooking Oils
Recycling Used Cooking Oils / Ecolife / Sander Tamm

An Overview On Recycling Used Cooking Oils

We love our fried foods! Whether we’re deep frying french fries and chips or cooking up a batch of donuts, we go through a lot of cooking oil, especially in North America where we’ll deep fry almost anything, including candy bars! But throwing that used cooking oil down the kitchen sink isn’t the most eco-friendly way to dispose of it, so we’re here to give you some cooking oil disposal guidance.

Why you should think about cooking oil recycling

Perhaps you’ve never thought about it, but disposing of cooking oil down the drain can actually have adverse impacts on the environment in more ways than one.

  • Contamination: Cooking grease will coat pipelines in the residential sewer system and is one of the most common causes of clogs and sewer spills. When sewage leaks into the environment, it can cause human and environmental health problems because of the pathogens and other potentially toxic waste it contains.
  • Wasted fuel: Used cooking oil can be used as fuel for a variety of purposes, so dumping it is a waste of resources. Scotland, for instance, held a campaign where one can pay for the bus with a batch of recycled cooking oil!

Reusing cooking oils in the household

Reusing cooking oil in the kitchen is simple and eco-friendly, but be sure to practice safe reuse methods:

  • Strain it with cheesecloth to get any food debris out (this will cause the oil to spoil faster)
  • Keep fats of different types separate from each other – animal and vegetable fats in particular
  • The oil should be covered and kept in a cool, dark place to avoid oxidation of the oil (if you won’t need it for awhile, store it in the fridge)
  • Watch for signs of rancid or deteriorated oil, including a darkened color, increased viscosity, loose food particles at the bottom of the container, smoking when heated to 190 degrees C (375 degrees F), or an off/rancid smell.
  • When reusing the oil, be sure that you raise the temperature to a minimum of 190 degrees C (375 degrees F) again to kill any bacteria that may have contaminated your oil.

In addition to kitchen, used oil can also be reused for other household purposes:

  • Repurposing: Used oils can become new things, like homemade soap, natural insect spray, or bird feed for your bird house. And if you’re really ambitious, you can try making homegrown biodiesel.
  • Donate it: If you can’t reuse your cooking oil, you will probably find other people in your community who would happily take it off of your hands. For instance, small amounts of waste cooking oil can be used in composting. As such, it is possible to successfully repurpose used cooking oil by simply handing it over to a next door neighbor interested in gardening.

Recycling cooking oils

Cooking oil recycling for the purposes of making biodiesel involves putting it through a process called transesterification in order to be useful in a vehicle’s gas tank. But before that happens, you need to get your used cooking oil to a recycling facility:

  • Set up collection: Being prepared to collect your used cooking oil will make the process much easier. Set up a collection system with a lidded heat-proof container that’s in a convenient place.
  • Don’t add water: Water and oil really don’t mix during the biodiesel-making process, so it’s best to keep all moisture out of your collection bin (that’s where the lid comes in handy).
  • Curbside recycling: Many recycling centers in North America and the UK will collect used cooking oil for recycling, though you should confirm this with your local authority, ensuring to ask how to package it properly.
  • Drop-off recycling: In some communities, cooking oil recycling drop-off locations will pop up just after major holidays like Thanksgiving to keep up with the increased demand for this type of recycling service, so check with your local recycler to see if this is the case.