There are multiple reasons why cooking oil might have gone bad, from its age to its storage conditions. However, it can be more difficult to tell if it has actually expired. This is because cooking oil often looks unchanged, despite actually having gone rancid.
While someone who works with cooking oil regularly, like in commercial settings such as restaurants, cafes, hotels and schools, will find it easier to identify expired cooking oil, it’s somewhat more challenging for someone who wishes to cook in their own home. But once you’ve used this article to identify rancid cooking oil, you’ll need to dispose of it.
You should NEVER pour it down the drain or the toilet. You should put it into your household waste bin or take it to your local recycling centre if you have a small amount. If you have a lot of it, then we, here at Cater Oils, can collect it and recycle it for you to keep your carbon footprint low.
Not only will we collect your waste cooking oil for free, but we’ll also either give you cash or a credit note against a fresh supply of cooking oil. But before we go any further into our used cooking oil collection service, you first need to know what the signs are of expired cooking oil.
In this article, we’re going to go through what the signs are that suggest cooking oil has expired, whether it be vegetable, rapeseed, olive, pomace or sunflower oil. So, let’s delve deeper into the signs that cooking oil has gone bad:
Unpleasant or rancid smells
One of the easiest ways to tell whether or not your cooking oil has gone bad is to smell it. If the oil is fresh, then it will have a mild, neutral or characteristic aroma, depending on its type. Olive oil, for instance, will smell and taste different from peanut oil, and vice versa, so it should be obvious whether those oils are fresh or not.
If the oil has gone rancid, regardless of the cooking oil type you choose, it will have a very strong, pungent and generally unpleasant smell. It can also smell stale, musty, sour or, in some cases, like old paint or chemicals. Basically, if it smells “off”, it’s best not to use it. Choose Cater Oils to dispose of it for you safely and responsibly.
Sour taste
If you’re still unsure after smelling the oil, then tasting it can provide you with another clear clue. If, however, you’ve already looked through this list and you think it’s gone bad without tasting it, then don’t bother sampling it. But if you still aren’t sure, then tasting it can be a good route forward to determine whether your cooking oil has expired. Once you’ve tasted it, rancid oil will taste sour, bitter, stale and just generally unpleasant. If it’s noticeably unpalatable, then the cooking oil has gone bad.
Colour has changed
Another easy way to tell whether or not your cooking oil has expired is simply by looking at it. Rancid cooking oil changes colour over time, indicating that the oil is long past its best. Depending on the type of oil you use, it can become darker or cloudier.
If you’re going to use colour or appearance as a way of determining whether your oil has gone bad, then you should research the specific type of oil you have. For instance, some oils will naturally become cloudy when stored in cooler temperatures.
Unfiltered or less-refined oils can also contain particles or sediments that other oils don’t, which is another example of where the appearance test alone wouldn’t work. Instead, you should see whether it comes in combination with other signs on this list to be sure.
It’s thicker or stickier
If cooking oil has expired, then it can become thicker and stickier in consistency. It may take longer to pour than usual, or it comes out gloopy and jerky. This is another indication that your oil has gone bad. It signals oxidation, which is usually accompanied by unpleasant smells and flavour.
Excess foam & smoke when cooking
Cooking oils will have different smoke points, but if, when frying or cooking, the oil smokes quickly or excessively, or if it’s foaming and bubbling, then it signals the degradation of the oil you have. Essentially, if it looks unusual or if it’s smoking, foaming or bubbling more than it normally would, then it signals the expiration of the oil you have in the cupboard.
The best-before date has long passed
The best way of checking to see if cooking oil has gone bad is to simply check the best-before date. While it’s not something that can determine its expiration with absolute accuracy, it’s certainly a good indication as to how old the cooking oil actually is.
If the date on it says “Sept 2017” and it’s now September 2026, then it’s safe to say that you shouldn’t use that cooking oil, for obvious reasons. But if it’s only, say, 3 months out of date, and it comes with all of the other signs in this article, then it’s expired.
Cater Oils offers a free waste cooking oil collection service, making it easy for businesses to dispose of used oil responsibly. To find out more about our waste cooking oil collection service, our range of fresh cooking oils, or how recycled oil is transformed into biodiesel, get in touch with our friendly and experienced team today – we’re always happy to answer your questions and help you find the right solution for your business.
