Ok, so I promised a blog about how to store food oil more than a month ago, but you know how summers go…

I do (eventually) keep my promises though. Like so many things in life, I’ve found some sources that have said to do other than what I’ve listed below, but most of them made the recommendations I’m making. This is a small part of my nutrition book I’m still working on.

Unfortunately, I’ve fallen behind on my book writing time, as I’ve been busier working more time in clinic (not a bad thing for me!). It’s always a matter of adapting and modifying while trying to stay on target (am I the only one who thought of Star Wars with those last 3 words?). Oh, and in cutting and pasting my book piece below, I notice I made another Star Wars reference in the very first paragraph. 

How to store food oil

As with almost all food products (honey is an odd exception), oils can go rancid. Depending on the type of oil, some will spoil faster than others, so it’s important to know how to store food oil properly, and how to identify oils that have gone bad (not to the dark side—as you’ll see, oils generally stay “good” longer in the dark).

Oils that are rancid smell different—sharp, bitter, or unpleasant. I think it tastes like Playdough, but others might say it tastes like crayons or putty. Keep in mind that the best before date may not tell the whole story. If you have an open half-used bottle of olive oil that has been sitting for a while, smell it to see if it’s still okay. The air in the bottle is called “headspace,” and oxidation from that air causes free radicals (usually “free” is a positive word, but not in this context) that can cause us health damage if consumed regularly. You won’t likely get sick from it from just a few doses, but the taste will also be altered, potentially ruining the flavour of your food.

Heat, oxygen, and light are all enemies of oil. The more saturated the oil, the most stable it is. This is why coconut oil makes a good cooking oil and is often jarred in clear containers, while olive oil makes a better salad oil and comes in dark glass bottles. The most sensitive oils are the essential oils and polyunsaturated fats. They often have to be stored in the fridge.

I know it’s convenient to have your cooking oils stored on or around your stove, but if they are exposed to heat, they will deteriorate more quickly.

Check your oil containers to find out how they should be stored, but here are some general rules:

Keep in fridge

Polyunsaturated oils are best kept in the fridge once opened. Some of these oils may become more solid and cloudy while being stored in the fridge. If it does, remove it from your fridge and have it at room temperature for an hour or two before use.

• Flax seed oil
• Grapeseed oil (can be stored at room temperature—assuming your room is less than 21°C/70°F—for up to 3 months or in fridge for up to 6 months)
• Hazelnut oil (same as grapeseed oil)
• Hemp oil
• Safflower oil
• Sunflower oil
• Truffle oil
• Walnut oil (same as grapeseed oil)

Keep in cool, dark place

Some of these oils can also be kept in the fridge to keep them lasting longer, though because of their higher quantity of saturated bonds, they are more likely to become solid.

• Avocado oil
• Coconut oil (very stable, this oil is often solid or semi-solid at room temperature)
• Macadamia nut oil (though high in polyunsaturated fats, it is also naturally high in antioxidants that help keep it stable)
• Olive oil
• Peanut oil

Do you have any tips on ways you’ve learned how to store food oil? Share in comments below.