How to compost and recycle cooking oil
Composting cooking oil
Can you compost cooking oil? This is a common composting query that a simple google search doesn’t seem to provide an adequate answer to. And it’s because the answer is not really that straight forward.
All organic matter is compostable, so technically the answer is yes. However, some waste is more complex than other waste and this effects the time it takes to break down. Oil falls into this ‘more complex’ category and so will take longer to break down than say your simple fruit and veg. There are plenty of people who advise against composting oils on the basis that the average home compost pile doesn’t get hot enough to break down more complex materials like oil. This will lead to rot, attracting rodents, smells, will reduce the air flow through your compost heap, displace water and ultimately threaten to kill the compost.
While these folk have a point, I don’t entirely agree. I think the real question is how much you can add and ensure your compost remains healthy. If you add only enough that your compost pile can actively absorb it into the composting process, it will be fine. How you strike the right amount is more difficult to answer. As is always the case with composting, it’s a case of balance and of trial and error.
My advice is to add small amounts to the compost pile comparative to other food items. Be conservative and push it a little further only when you’re confident. If you have a worm farm, the same rule applies. For my small urban worm farm, I’ll throw in paper towel that I’ve used to wipe out fry pans with success as well as other scraps with small amounts of oil involved. But I don’t throw in run off from the fry pan following deep or shallow frying – I think that would overwhelm the worms. I also make sure I dig the scraps through so it’s well integrated into the farm.
If you have left over food cooked in oil (with the exception of meat), they can be composted using the same rule: if you don’t think the oil factor is going to upset the balance, go for it!
The thing is, if you run a small family compost pile, this isn’t going to solve your cooking oil problem. So what else can you do to ensure it doesn’t go to landfill?
Reusing or Recycling Cooking Oil
- Use less
This isn’t always practical advice, but I do find it helpful to be mindful of how much oil I actually need for my cooking. Although I don’t tend to strictly stick to measurements when cooking, I do find I use less oil when I measure it out. Or, when you do have an option, you could choose to shallow fry rather than deep fry; steam rather than fry.
You can recycle large quantities of cooking oil for reuse in the kitchen. Why not strain and strain and store for future cooking use? This works for animal fats (bacon, beef) as well as plant-based fats (olive oil, sunflower oil). You will need to take care that the latter, however, does’t exceed its smoke point. This will make it unsuitable for re-use. Otherwise, strain through cheesecloth and store in an airtight container in the fridge.
- Make Soap
I am yet to try it, but love the idea. Check this recipe out if you want to give it a go.
- Give it to your animals
If you have an active dog, a small amount of oil added to your dog food will ensure a shiny coat and your dog will love it (and don’t worry, he will work off the extra calories). Or Roll used solidified fat in bird seed and stuff it into an old stocking to hang out for the birds as a feeder.
- Make biodiesel fuel
Some commercial users might want to consider recycling their cooking oil as biodiesel but this isn’t so practical for home cooks because you just won’t have the quanitities.
- Curb-side and drop-off recycling.
Ask your local authorities for disposal options.
What not to do
Avoid putting any cooking oils down the drain or the toilet – it clogs drains and sewerage pipes and it pollutes waterways. If you can find an alternative use for your oil than sending it to landfill, that’s ideal. Of course, that’s not always the case. If you do put your oil into the rubbish, before you do, seal it in a container and place it in a reused plastic bag.