Want to store butter to have on hand in case of an emergency? Here’s what you need to know about storing butter long term so it stays safe and good to eat for years.
The Quick Answer:
Commercially-made butter has a very long shelf life, even without special packaging. It should last at least 6 months in the fridge, kept in a sealed container, and indefinitely in the freezer.
For long term storage, though, it’s best to buy butter powder packaged with oxygen absorbers. It is shelf-stable, so you don’t have to worry about it going bad during a power outage.
How to Store Butter Long Term
1. Butter Powder in Airtight Packaging + Oxygen Absorbers
Butter powder is made with a fairly complex process in which the oil is separated and mixed with emulsifiers. The result is a stable product at room temperature: you don’t need to refrigerate it. To use butter powder, you simply mix it with water.
How long does powdered butter last?
Many emergency food brands sell butter powder packaged in airtight containers (such as Mylar bags or #10 cans) with oxygen absorbers.
This packaging method creates an oxygen-free environment, so the butter powder is less susceptible to going rancid. As a result, butter powder can last 10 years without losing quality.
When packaged without oxygen absorbers or once the package is opened, butter powder is only good for about 1 year after its manufacturing date.
For more, read Best Brands of Butter Powder
2. Freezer
Oxidation slows down in cold temperatures, so storing butter in the freezer will prevent it from going rancid. To store butter in the freezer, just put it in a sealed container. Otherwise, it may absorb smells and odors from other items in the freezer.
How long does butter last in the freezer?
Butter can be stored indefinitely in the freezer. Various studies show that even after 18 months in the freezer, butter won’t lose its quality.
3. Fridge
You can store butter in the refrigerator long-term. However, you must keep it wrapped in air-tight packaging or in a sealed container. This will keep the butter from coming into contact with oxygen, which could make it go rancid. It will also keep the butter from absorbing odors from other items in the fridge.
How long does butter last in the fridge?
So long as it doesn’t come in contact with spoiled foods or utensils, butter kept in the fridge will remain safe to eat for over a year. However, the quality will start to deteriorate after approximately 6 months. At that point, you may notice some stale or rancid flavors.
Does Butter Go Bad?
By law, butter must contain at least 80% fat. Because it has such a high fat content, it won’t support microbial growth. This is why butter doesn’t go bad like most other dairy products. However, butter will deteriorate in quality and go rancid over time. In this sense, butter does spoil.
What Does It Mean for Butter to Go Rancid?
Like nuts, oil, and whole grain rice, butter is susceptible to going rancid. When butter goes rancid, the fats in it have started to oxidize. They undergo chemical changes that cause them to get a sour, metallic, or even fishy taste and odor.
While eating rancid butter is generally safe in that you won’t get food poisoning, it’s a sign that the butter has gone bad.
Many butter brands add antioxidants such as lycopene to their products to slow down rancidity. However, the best way to prevent the butter from becoming rancid is to seal it in an air-tight container and store it in a cold location.
Can Bacteria and Mold Grow On Butter?
Butter does not support bacterial growth. The moisture content of butter is so low that bacteria and mold cannot grow on it. Butter’s high fat content and its natural antioxidants also inhibit microbial growth.
This is why you don’t have to worry about food poisoning from eating old butter like you would with many other dairy products, such as milk and yogurt.
However, there are types of butter that can get moldy or grow bacteria. These types of butter are NOT suitable for long-term storage.
Traditional Butters
To make butter, cream is churned to separate the fat and water. The fat is lighter, so it floats to the top, and the water is drained off. Hand-churning doesn’t do as good of a job at separating the fat and water. As a result, traditional butters have lower fat content and higher water content than standard butters, meaning they go bad faster.
Modified Butters
Many types of butter are modified to contain less fat and more moisture and thus are more likely to spoil.
These types include:
- Whipped Butter
- Sweet cream butter
- Reduced fat butter
Raw or Unpasteurized Butter
Raw butter has not been pasteurized, meaning there may be microbes in the cream used to make the butter. Because of this, raw butter is more prone to spoilage. The shelf life of raw butter in the refrigerator is usually just 60 days.
Margarine
Margarine and other vegetable-based spreads typically contain 40% to 60% fat. Their lower fat and higher moisture content make them more prone to spoilage. They should not be stored long-term!
How Long Can Butter Be Left Out During a Power Outage?
Butter is safe to eat even if it has been out of the fridge for weeks. However, it only takes a few days for unrefrigerated butter to start developing rancid flavors.
Because of this, you might want to think twice before you stockpile large amounts of butter in the fridge or freezer. If a power outage occurs, all the butter could spoil quickly. It may be better to stockpile powdered butter instead. Or ensure you have a generator for running your fridge.
