Does Whey Protein Go Bad? How Long Does Whey Protein Last?

Some of us stock up on protein powder when it is on sale at the grocery store. Sure, it may be fast approaching its “best by” date, but that doesn’t mean anything, does it? Does whey protein go bad?

Most sources agree that whey protein is best used within two years. Many other sources believe it is best used in less than one year. Properly stored and kept dry, whey protein is safe to use indefinitely, though it will become less effective over time. It is not possible to define a time-frame for this, because so many different factors play a role.


The “best by” date on the package is a good guideline for how long that protein powder will remain effective in helping you build muscle and manage your health, but it is not a hard rule that it will make you sick if you use it after that date.

Does Whey Protein Go Bad? How Long Does Whey Protein Last?

There are numerous factors involved in determining how long whey protein can keep its peak quality. Read your package carefully, especially the list of ingredients, and any storage or handling instructions.

How Long Does Whey Protein Last On The Shelf?

At room temperature, stored in ideal conditions, whey protein can last up to two years, typically. The danger to this type of protein powder, is that it can attract moisture and bacteria once opened, and will degrade with more exposure.

Some brands of protein powder will use additives as preservatives and extend the shelf life of their whey product. Other types will have included vitamins or additives that will not last as long as the whey protein.

Be aware of what is in your whey protein powder and watch for signs of spoilage before consuming. It is likely, however, that your whey protein will remain safe and effective for up to three months after the best by date.

How Long Does Whey Protein Last in the Fridge?

As a dry powder, whey protein should not be stored in the refrigerator. The temperature changes involved in taking it out to use it and then putting it back will cause condensation inside the container.

You can prepare whey protein in a shake and refrigerate it for up to 48 hours, unless you have mixed it with fruits or other ingredients that do not last as long. Shake it well before drinking it, the protein powder will separate.

If you have prepared baked goods or other dishes with whey protein, those can also be refrigerated for up to two weeks, like recipes that contain any other type of milk.

How Long Does Whey Protein Last in the Freezer?

If you find that you have brought home far more whey protein powder than you can consume in a reasonable amount of time, the freezer is one option. It does not help prolong the quality of your powder, however.

Dry whey protein will not last longer in the freezer, but it will not be harmed unless you expose it to moisture. Just like with the refrigerator, the condensation created with the container is transferred from cold to warm temperatures is the biggest danger to whey protein.

When blended into a shake or another recipe, you can store whey protein without causing any damage to the protein. It can keep fresh about the same amount of time as a milk product.

Most sources agree that whey protein can last 9-19 months if it is stored properly and sealed against moisture, light, and heat. Take care of it, and it can potentially last even longer.

How To Tell If Whey Protein Has Gone Bad / How To Know If Whey Protein is Fresh

If you notice changes in your protein powder, you should be aware that in the worst scenarios, it can attract bacteria that you should not consume. Judge your container against how it looked, smelled, and tasted the day you opened it, as each type of whey protein powder can change in different ways, depending on how they are made and what they are blended with.

Foul Odor: If it begins to smell rancid, like souring milk, it has been contaminated with moisture, and there is bound to be bacteria growing in there that might upset your stomach.

Clumps: Clumps forming in your whey protein is another sign of moisture exposure. Just a drop or two of water can form these clumps, and it is recommended the entire container be tossed. Some consumers will just scoop out the clumps, but try it at your own risk.

Color: If the powder was white when you bought it, it probably has been bleached, and will turn yellow or brown when it goes bad. Whey is naturally off-white, but if it darkens, throw it out.

Cardboard taste: Whey protein may not taste great on its own when it is fresh, but it should never taste like cardboard. When it does, you know it is time to get a new tub or bag.

How to Store Whey Protein?

Proper storage is the key to maintaining freshness in your whey protein. Whey protein degrades in quality over time. It is not as likely to make you sick, but it does become ineffective.

The best way to store whey protein is in a dry, dark, cool place. Your pantry or cupboard is ideal. Light, heat, and moisture are the enemies of protein powder. Keep the container sealed tightly against air and moisture.

Storing the whey protein in the refrigerator and freezer is not necessary. Condensation may build up on the inside of the container, and the powder will absorb the moisture.

Do not keep whey protein on top of the fridge. The heat produced by your appliances is too much for whey protein. It will spoil in a dangerous way.

Can You Freeze Whey Protein? How?

Keeping whey protein in the freezer is not usually necessary, but it is possible. If you need to, and choose to freeze your protein powder, there are a few different ways to do it. It will not damage your protein, but it will not necessarily keep your protein powder fresh any longer than storing it at room temperature.

It is recommended you separate the protein into smaller portions. This way, you can use only what you need, and you will not have to expose the majority of your powder to the condensation created every time you pull a package out of the cold. You still want to make sure you use it within 3 to six months.

You can freeze mixed whey protein shakes. Just make sure to mix them thoroughly and use an airtight freezer-safe container. It is reported that freezing whey protein shakes can alter the taste and texture, but it should be fine for the nutritional value. Thaw it in the fridge overnight for the best results and mix it again thoroughly before you drink it.

How to Thaw Whey Protein?

If you are going to freeze your whey protein, dry or mixed in a shake, you will want to know how to thaw it before you can drink it.

Whey protein is best thawed in the fridge overnight. This can reduce the condensation that can make your protein powder spoil quickly.

You can also use the defrost function on your microwave if thawing a frozen protein shake. Be careful not to overheat, however, you want it to stay cold.

Frequently Asked Questions About Whey Protein’s Shelf Life

Whey protein is fairly straightforward, but there are still questions that can be asked about this important macronutrient.

Can unopened whey protein last longer? Sometimes you can prolong the life of a dry ingredient for years just by keeping it sealed in your pantry. With whey protein, however, unless it becomes exposed to moisture, it does not matter if you open it or not. You can expect it to be spoiled after two years, even if the seal has never been broken.

Is it bad if there are no signs of spoilage? Probably not. Whey protein will smell, look, or taste wrong if it has gone bad. So even if the container is past its best by date, if it still seems to smell, look, and taste the same way it did when you first bought it, it is likely still fine to consume.

Wrap Up

Whey protein is sourced from dairy, as is casein and milk powder. Most dairy products you may know of spoil rather quickly. What sets protein powder apart is the dry environment, where microbes cannot grow. Keep it dry and cool, and whey protein should stay fresh for 9-19 months on average.

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