Why Storing Fats and Oils Long Term is Difficult and Why We Need Them
Storing fats and oils long term requires defining "long term" - which I'll do in a moment. The problem with storing any fats and oils is oxidation — exposure to oxygen causes rancidity. Rancidity has been implicated as a cause of cancer (a carcinogen), heart disease, and arteriosclerosis.
On the other hand, fats are important for our health. They add taste and texture to our foods, as well as help our bodies absorb fat soluble vitamins such as A, D, E, and K.
In a crisis situation, we may not be able to obtain all the calories we need if there is not enough food, so fatty foods will provide the calories needed.
If our food storage supplies consist of mainly grains and legumes, adding a little fat or oil to a recipe provides the needed source of concentrated calories.
So in defining "long term" as applicable to storing fats and oils, it is only practical to store them for a year or two, if (and that's a big IF) they are properly preserved and stored.
Here are a few general rules to help you determine how long to store fats:
- Avoid exposure to heat, light and oxygen. The more exposure to these three factors, the sooner rancidity can set in. To lengthen the life of your fats and oils, buy them in darkened, airtight containers (vacuum sealed is preferable) and refrigerate after opening. Regardless of the packaging, store at the coolest temperature you can provide.
- Rotate your fats and oils. It is important that you not buy more that you can use and rotate over several months. Manufacturers do add preservatives, which will help to extend the shelf life. Be sure and check expiration dates when purchasing at the grocery store - fresher is better for a longer shelf life.
- Buy fats and oils in smaller containers. Properly packaged, unopened cooking oils have a shelf life of approximately one year - some times longer if they have been specially treated, and depending on the conditions mentioned above. Be aware that specialty oils such as flax seed and sesame have an even shorter shelf life, so be sure to refrigerate after opening. They may become cloudy or solid but are still usable and will return to their normal state at room temperature. Opened bottles can begin to turn rancid in a matter of weeks to a couple of months, often long before they smell rancid.
- Buy lighter colored oils. Darker colored oils are more flavorful than the lighter colored oils, but the lighter oils have a longer shelf life.
- Use solid shortening for longer shelf life. The fat with the longest shelf life (store-bought) is Crisco™. Crisco is hydrogenated shortening and includes preservatives, which accounts for its longer shelf life. It's impossible to know for sure, but any brand of hydrogenated shortening with preservatives, unopened and kept in a cool environment, should last 8 to 10 years.
- Coconut Oil. As it turns out, coconut oil is a great option for cooking due to its high smoking point (350°F for unrefined and 450°F for refined). This means that you can sauté and bake with coconut oil and not worry about it turning into a trans-fat. Plus, coconut oil is very stable. It has more than a two-year shelf life and won’t become rancid, even in warm temperatures. (This is one of my favorite brands.)
Also, there appears to be strong evidence that coconuts are an anti-viral, anti-bacterial, anti-fungal, and anti-inflammatory food. Plus, the research behind its heart and weight benefits seems well founded.
Just to stress the importance of proper storage and rotation, even with preservatives added, stored fats and oils that become even a little rancid are bad for your health and can even be poisonous.
Fat and Oil Products: