Canola oil is a cooking favorite, as it is inexpensive, and cooks well without imparting any additional flavors to the food. Despite being used fairly frequently in most households, it’s still entirely possible to have a bottle that goes unused for quite some time. Can canola oil go bad? Should you toss out that old bottle, or is there hope for it yet?
Can Canola Oil Go Bad?
Like all oils, canola oil does eventually go bad. Though it’s incredibly unlikely for mold to grow, or rot to occur, spoilage will still happen after a while. The main spoilage issue with canola oil is that it can become rancid easily. Rancidity occurs when the oil molecules become oxidized, through exposure to air, light or heat.
In addition to tasting rather unpleasant, consumption of oxidized fats can be damaging to your health, so eating rancid oil is strongly discouraged. Proper storage is important to extend the shelf life of your cooking oils for as long as possible.
Signs of Spoilage
The best way to tell that your canola oil has spoiled is to check for any off smells. Like all oils, canola oil will take on an unpleasant odor when it goes rancid. Before cooking any dish, be sure to check for rancidity by smelling the oil in the bottle. You wouldn’t want to pour oil over those vegetables, only to realize too late that it’s gone rancid!
There might also be changes in color as the oil begins to spoil. If you notice that your oil has become darker, you should certainly test for rancidity.
Image used under Creative Commons from Veganbaking.net
Storing Canola Oil
Canola oil should be stored in a cool, dark place in a tightly sealed container. It’s important that the oil has minimal contact with light, heat or oxygen to slow the oxidation process, and so storing canola oil next to the stove is highly discouraged. If properly stored, an unopened bottle of canola oil will have a shelf life of around two years, though depending on storage conditions, it is possible for the oil to go rancid is less time, so checking your oil before each use is important. Keep in mind that the oil will have likely been on a store shelf for a while before arriving to your kitchen.
Once a bottle of canola oil is opened, because of the exposure to air, the shelf life decreases to between six months and a year, depending on storage conditions. Refrigerating the oil will prevent it from going rancid as quickly, but won’t extend the shelf life beyond a year.
Freezing canola oil isn’t recommended, as it won’t extend the shelf life beyond a year. Additionally, freezing the oil will somewhat change the structure, making it go rancid much more quickly after the oil thaws out.
When purchasing canola oil, look for brands that are stored in a dark glass bottle, or in a canister. Both of these storage options will greatly reduce the exposure to light. If your bottle of canola oil came in clear glass or plastic, just be sure to store it away from light or heat.