Today’s post is inspired by a reader question that came in from Dustin:
What is a good way to store fats in your food preps? Can you talk about good fats to store, both in terms of their healthfulness and for long-term stability? What about liquid fats? Are there any oils you’d recommend for food storage?
This is a great question. There are some unique challenges when it comes to long(ish)-term storage of oils and fats, but no other macronutrient can provide as many calories in such a compact space. What’s a prepper to do?
I’ll go into detail about your best options and how to maximize the shelf life of your fats below, but first let’s get the health aspect of various fats out of the way. That’s really above my pay grade. I am not a doctor or even a healthy living blogger – so my personal opinion on the healthfulness of various fats really shouldn’t guide your dietary choices at all.
In my opinion, minimally processed, saturated animal fats are typically a better choice than highly processed seed oils or artificially hydrogenated fats. In my own kitchen, the only liquid fat I use with any regularity is olive oil. I do not buy, use, store or – within reason – consume – corn oil, canola oil, cottonseed oil, or vegetable oil which is typically made from soybeans.
That’s me. Your conclusions about the health aspects of different fat wills depend greatly on what your assumptions are going into it and which cherry picked experts you choose to listen to.
Rancidity: The Big Problem With Long Term Fat Storage
The biggest problem with storing any fat for a fairly long time is rancidity. Rancidity is a chemical chain reaction within the fat that causes an unpleasant, off smell and taste. A rancid oil has an acrid smell, like oil paint or nail polish remover.
“How did you go bankrupt?” Bill asked.
“Two ways,” Mike said. “Gradually and then suddenly.”
That’s kinda how fats go rancid. Gradually, and then suddenly.
There’s a period of time where the fat is fresh and non-rancid, then a period of time where rancidity is hardly perceptible but it’s there, very slowly chemically compromising your fat. And then, boom, your fat is rancid enough to be basically unusable. The trick to longer-term storage of fat is to maximize the time before that rancidity compromises your fat.
From a fat storage perspective, fats that contain more saturated fatty acids – these are fats that are solid at room temperature, like animal fats and tropical vegetable fats like coconut oil – store far better than liquid fats which are made up of mostly unsaturated fatty acids.
There’s some chemistry behind why, but it’s not really relevant to this answer. Just know that solid-at-room-temperature means a more highly saturated fat with a longer shelf life. This is great news for people like me who prefer lard to canola oil and the like.
The Problem with Rancid Fats
The first problem with rancid fats is they make your food taste terrible. The compounds formed through the rancidification process are not tasty.
The second problem is that rancid fats are bad for you. From my research, rancid fats aren’t immediately poisonous or likely to cause some kind of food borne illness. However, the byproducts generated as an oil goes rancid are associated with long-term health damage, including advanced aging, neurological disorders, heart disease and cancer.
Three Way Fats Go Rancid
Hydrolytic rancidity is a reaction of fat with water that causes the fat to break down. This is most likely to be a problem with butter, which is typically between 15% to 20% water. Ghee, which is butter with all the water removed, has a much longer shelf life than fresh butter precisely because it’s had the water removed.
Oxidative rancidity is a reaction of fat and oxygen. This is the most common reason fats degrade. Oxygen reacts with unsaturated fatty acids – it breaks them apart, releasing unpleasant smelling and tasting volatiles. Even saturated fats like lard contain a proportion of unsaturated fatty acids, so the fats we call “saturated” are still affected by oxidative rancidity. However, rancidification progresses far more slowly in fats with a smaller proportion of unsaturated fatty acids.
A lower proportion of unsaturated fatty acids in your fat, and reducing exposure to oxygen with airtight packaging greatly slows oxidative rancidity.
Microbial rancidity is when microorganisms, such as bacteria or molds, use enzymes to break down fatty acids. Sterilization procedures dramatically reduce the risk of microbial rancidity, and this kind of breakdown is unlikely to be a big problem in commercially processed fats or properly processed, home-rendered fats.
Increasing The Shelf Life of All Fats
For all oils – your everyday cooking oils and your storage fats – the goal is to slow down the onset of rancidity. All fats will benefit from these best practices in purchasing and storage:
- Purchase bulk oils from a high turnover places like Costco or a busy supermarket. Some random convenience mart could have a bottle of oil on the shelf 6 or 8 months before you buy it. That doesn’t give you a lot of time after you open the oil. I’ve even purchased oils that were noticeably rancid when I first opened them.
- Buy oils in size-units that you can comfortably use up within the reasonable storage life of that oil. If you use a pint-sized bottle of oil every 9 months, buying a 1-gallon jug is probably a big false economy.
- Only open one or two oils at a time if you can manage it. It’s a nice idea to have 12 different boutique oils for every culinary situation, but you don’t actually need them. Store any delicate boutique oils (hazelnut oil, etc.) you do have in the fridge.
- Storing unopened oils in their original sealed packaging.
- Keep oils cool and out of direct sunlight. Avoid heat cycles such as might happen in a garage.
- Don’t ever let water get into your fats.
- Use a perfectly clean utensil each time you remove solid fat from a container.
Prepper Strategies For Fat Storage
It’s my opinion that you just have to look at fats differently than other food storage staples like beans or wheat berries stored in mylar bags. You can go buy a #10 can of freeze dried butter from one of the prepper supply houses, but even that kind of specialty product has a maximum shelf life of about 10 years with ideal storage.
Because no fat has a decades-long shelf life, it’s typically best to build a deep, rotating pantry with up to several years of fats on hand that are consistently replenished. Slowly stock your pantry with a backstock of fat that can see you through however many months or years you are comfortable with. Be smart and organized with this – date and rotate, your first product in should be your first out.
More info on my philosophy of deep larder building here: Food Storage For People Who Don’t Hate Food
In figuring out how much fat to keep on hand, it’s useful to think about how you use fat and then also think about what percentage of your storage calories you’d want in fat.
Here’s an example of how the math might look for a family of four looking to build a 3-month food storage with 20% of their food storage calories coming from fat.
- 4 people in a family x 2000 calories per person, per day = 8000 calories per day food storage
- 8000 calories per day x 90 days total stored food = 720,000 calories total needed stored calories
- 720,000 total stored calories x 20% calories from fat = 144,000 total fat calories in food storage
- 1 gallon oil = 30,259 calories
- 144,000 fat calories / 30,259 calories per gallon of fat = 4.76 gallons of fat
- Therefore 5 gallons of stored oil will be a sufficient amount of fat storage for our 4-person, 3-month food storage scenario.
Fats are extremely dense calorically, which can be great for space efficient food storage. You may not need as much fat as you think you do, if you do the math on how many calories of fat you want to keep on hand. Or maybe you eat keto and you’ll need a lot more!
But the math exercise – which I did with my own family – is very useful in getting a baseline for how much total fat to keep on hand.
Medium Term Storage Fats To Consider
73% monounsaturated fatty acids, olive oil is longer lasting than any processed seed or vegetable oil. Buy from a place with high turnover and look for a best by date because the harvest and processing conditions of the oil can make a big impact of storability.
Typically, olive oil will last, unopened, 18 months to 2 years, but if bought very fresh, packaged in dark, metal tins, and stored well, you can get twice this storage life out of it.
Fresh butter is not a good choice for even medium term storage – even in the freezer it’s best used within about a year. But ghee – clarified butter – will stay in good condition at cool room temperature for about a year in it’s original sealed container, or 2 or 3 years in the fridge.
My fat of choice for cooking. Lard has been the poster child for “unhealthy saturated fat” for decades, but the irony is that lard is actually only about 40% saturated fatty acids, and 45% monounsaturated – the same kind of fat found in olive oil. All those unsaturated fatty acids mean that lard – while long lasting – doesn’t have an infinite shelf life.
Clean, home rendered lard will store 2 to 4 months at kitchen temperatures, and 12 to 18 months in the fridge or chilly root cellar temps. Frozen lard in air-tight packaging it will last years – at 3 years at least and probably twice that. Commercial lard with added stabilizers will last at least 2 years at cool room temperature if unopened, and probably twice that.
I haven’t personally worked with tallow in the same quantity as lard, but it’s similar in its fatty acid profile. You can expect an equivelent shelf life and longevity to lard.
At over 85% fully saturated fatty acids, coconut oil it the king of long lasting unprocessed fats! There are two common types of coconut oil. Refined coconut oil doesn’t have much of a taste or odor and is a bit better in high-heat applications. Unrefined coconut oil – also called virgin coconut oil – has a more pronounced “tropical islands” coconut smell and taste, and has a slightly lower smoke point.
Both refined and unrefined coconut oils are highly saturated, solid at temperatures below 76 degrees, with excellent storage abilities. Officially, most manufacturers will say a sealed tub of either refined or unrefined coconut oil should last 2 years. Unofficially, preppers and coconut oil hoarders are reporting coconut oil storage life of 5 years and more.
A third, less common, type of coconut oil is fractionated coconut oil. This oil has been additionally processed to remove certain fatty acids from the coconut oil. This processing removes the coconut taste and smell, and makes the coconut oil liquid even at cool temperatures.
Cosmetic grade fractionated coconut oil is popular as a massage and carrier oil and skin and hair product. Food grade variations on this type of oil are popular with low carb and paleo folks who are trying to increase their intake of medium chain triglycerides. A fully saturated fat, food grade fractionated coconut oil has a long shelf life but is used more as a dietary supplement and typically has the price point to prove it. I don’t consider it a viable fat for versatile culinary food storage.
Vegetable shortening (Crisco) contains unsaturated liquid oil (Crisco uses soybean oil) that is made partially saturated through a process called hydrogenation. Basically they force a bunch of extra hydrogen molecules into the liquid oil, causing it to take on a molecular structure like a saturated fat. This is why Crisco and margarine are solid at room temperature.
I never, ever, ever use vegetable shortening in my cooking, but I still keep a small tub of it on hand. Why? Shelf life and versatility in an emergency. Crisco candle anyone? The Crisco company says you’ll get 2 years at room temperature out of their shortening, but anecdotal evidence from preppers suggests 10+ years or more.
There are a few other boutique fats like that have decent storage profiles but they are either ecologically inappropriate to promote, or ridiculously expensive and not appropriate for broad culinary use.
The Fats I Store
The vast majority of my shorter term fat storage – the stuff I’d go through within a year or two – is olive oil. The vast majority of my medium term fat storage is in coconut oil. I keep enough on hand for several years, and as one tub is used up I replace it with another one from the store, always trying to keep my backstock nice and consistent.
When you consider how much fat to keep on hand, look at your dietary and cooking needs, but also at the personal care uses for some of these fats. In other words, if you’re in a situation where you’re tapping into your deep backstock of fats, are you maybe also in a situation where you’re making your own soap, or making your own herbal salves?
Many fats like coconut oil, lard and olive oil have important and traditional uses in personal care as well.
What kinds of oils or fats do you keep on hand?
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This question originally came to me in my recurring role as an Expert Council Member on The Survival Podcast. My Expert Council answers to productive homekeeping and food preservation questions can be found on selected Survival Podcast episodes.