Powdered milk is a fixture in most kitchens. It’s used in all sorts of baked goods and other dishes, as a shelf-stable substitute for liquid milk and also as an emergency preparedness ration.
It is easy to prepare without electricity, nutritious, and it doesn’t taste too bad once you get used to it.
There’s a lot to like about powdered milk, but the concern with any dairy product is always how long it can last before it spoils. So, how long does powdered milk last?
Powdered milk can last 10 years or longer in storage if unopened and kept in ideal conditions. Moisture, air, light and heat are all contributing factors to spoilage.
When it comes to long storage life dairy, it really does not get any better than powdered milk, but even it can go bad if it is stored carelessly or if you don’t pay attention to conditions.
Even so, it’s easy to get a very long life out of your powdered milk with a few simple tricks. I’ll tell you all about it below.
Storage Life for Low-Fat Powdered Milk:
| Dry, Opened | Dry, Unopened | Dry, Freezer | Mixed, Room Temp | Mixed, Refrigerator | |
|---|---|---|---|---|---|
| Expected Shelf Life | 1 to 3 months | 10+ years (if kept cool) | Indefinite | 1 day | 4 to 6 days |
What is Powdered Milk Exactly?
Powdered milk, also known as dry milk or dehydrated milk, is nothing more than a dehydrated form of liquid milk.
It is made by evaporating the water from the liquid, leaving behind a powder that contains all the essential nutrients found in regular milk, including the protein and calcium.
Powdered milk can be made using a few different processes, but the end result is always a powder that can be used for baking and other recipes, or reconstituted by adding water to it and using it as a substitute for regular milk in any recipe. Or, just for adding to your coffee or pouring over cereal!
In short, powdered milk really is milk, just milk that has been dried…
Don’t Mind the “Expiration Date” on the Package
One thing to clear up right away is the “expiration date” on the package. This is what always gives people pause when considering powdered milk storage, because it looks like it will expire quickly.
Most brands have a date set around a year to a year and a half from the date of packaging.
But in truth, this “expiration date” is not really an expiration date at all. It’s more of a “best by” date or “use by” date, meaning that you can still use the product after that time has passed!
You can expect, possibly, some degradation in taste and overall quality after that date, but your powdered milk will still be safe to consume after that date for a time so long if proper storage procedures are followed.
But this also means you’ll need more info to know truly how long your powdered milk can last in storage.
Powdered Milk Keeps for a Very Long Time if Protected from Air and Moisture
So, back to the main question: how long does powdered milk last? The answer is that if you store it right, then your sealed package of powdered milk should remain safe to consume for at least 10 years, and some projections that it can last 25 years or even longer!
The key, as with any other dry food product, is to protect the powder from air and moisture. Once exposed to moisture, bacteria will start to grow on the milk powder pretty much right away.
There is generally no saving powdered milk if it has been exposed to moisture that infiltrates the packaging, and this is another reason why you should pick a storage location that will be safe from humidity and flooding.
But the good news is that most powdered milk containers are reasonably good about keeping moisture out over time as long as they are factory sealed (more on that in a minute).
If you have a choice, though, you should opt for a heavy, metal or plastic can or thick plastic bag, as they are the most moisture-proof forms of packaging and will help in achieving the longest shelf life.
Cardboard canisters and tubes are far more likely to absorb moisture over time.
Higher Fat Content Equals Shorter Shelf Life
Another thing to keep in mind is that the intrinsic shelf life of powdered milk is closely tied to the fat content of the milk itself. Simply stated, more fat means faster spoilage.
Your low- and no-fat milk will last the longest, 10 years or more as stated. Whole milk and buttermilk might only get a couple of years in ideal conditions.
Also, note that powdered baby formula does not have the same super-long shelf life of classic powdered milk.
This is because of the very high-fat content! Most powdered baby formulas will only last a year in good conditions if unopened. Use it, or lose it!
Keep it Cool, Keep it in the Dark
So, we know that we need to control the air and moisture to keep our powdered milk safe and sound for the long haul.
You should also know that heat and light are also enemies of your powdered milk over time.
Heat is a problem because it causes fats to break down faster. Light is a problem because it heats containers!
In any case, heat means that the fat breaks down and then goes rancid, meaning your powdered milk will spoil, or at the very best taste nasty.
Keeping your stash of powdered milk in a cool place will reduce the rate at which that happens and extend its shelf life.
All other things equal, a container of powdered milk kept in a spot that is 50 degrees Fahrenheit (10 Celsius) will last up to 3 times as long as the same container kept at 75 degrees Fahrenheit (23 Celsius), and more than 20 times longer than a container kept in scorching 90-degree temps!
In that latter example, a can of powdered milk could start tasting “off” or looking discolored in as little as 30 days even if factory sealed, and go bad within a few months.
The container kept in a chilly 50-degree (10 degrees Celsius) room could last for 10 years or more as described above.
If You Open Powdered Milk, it Will Go Bad Faster
Remember: All of this advice and guidance only applies to powdered milk that is still sealed in its factory container. If you open powdered milk, you have started a clock ticking on spoilage.
That’s because it is then far more vulnerable to our two biggest threats, air and moisture. Opened powdered milk may only last another month or two in good conditions.
Don’t expect any powdered milk you’ve opened to go the distance unless you take steps to repackage and preserve it.
Use Extra Care if Repackaging Powdered Milk
If you do decide to repackage powdered milk into a more suitable container, or you want to preserve a leftover portion you’ve opened, use extra care.
Vacuum sealing, be it in a mylar bag or a mason jar, is a must, and you should also consider including oxygen absorbers and desiccant packs to eliminate air and moisture from your newly sealed package.
If you go this route, you might actually get a much longer shelf life than the original container.
Having said that, repackaging is no guarantee of success, and it may be more trouble than it’s worth: powdered milk is already very space efficient compared to its liquid form!
You Can Freeze Powdered Milk, Too
It is also possible to freeze powdered milk, however, it is not the ideal long-term method.
Freezing stops spoilage and can keep your milk almost indefinitely, but problems with moisture will abound especially if you are opening and closing your freezer regularly.
That said, if you have a chest freezer or spare fridge that you don’t open often, it is still a viable option for long-term storage so long as you keep the electricity on.
Powdered Milk May Lose Flavor but Still Be Safe
Whichever way you decide to store your powdered milk, keep in mind that it won’t necessarily taste grocery-fresh when you finally pull it out.
Its flavor will likely be lessened, and it might taste bland and flat. But it should still be safe to eat if you haven’t noticed any signs of spoilage.
What are Signs Your Powdered Milk Has Spoiled?
Despite its reliably long shelf life, it is important to know the signs that your powdered milk has spoiled. Here are some ways to tell if it has gone bad:
- There may be a change in color, and the powder may appear yellowish or tan instead of white or off-white.
- An “off” or foul odor or taste.
- The texture of the powder may feel clumpy, gritty or grainy.
- A slimy residue is present in the container.
- Any obvious signs of mold.
If you have any doubts, don’t risk it! Throw it away and get or open another container.
Tom has lived and worked on farms and homesteads from the Carolinas to Kentucky and beyond. He is passionate about helping people prepare for tough times by embracing lifestyles of self-sufficiency.