American Cheese: Why Does It Last So Long?

American cheese is a processed cheese product that was invented by James L. Kraft in 1916. Kraft wanted to create a shelf-stable dairy product that could be shipped long distances without spoilage. The preservatives in Kraft cheese and similar products are the reason why American cheese has such a long shelf life. The exact length of time that American cheese lasts depends on storage conditions and whether the product has been opened. However, unopened sliced American cheese can last for up to eight months in the fridge and two months beyond its printed expiration date. Once opened, American cheese should be used within a week.

Preservatives in American cheese

American cheese is processed cheese, which means it is made from natural cheese that has been heated and blended with emulsifiers to give it a smooth texture and better meltability. This process also helps American cheese last longer than other cheeses.

The preservatives in American cheese have been a source of controversy. In 2014, Kraft replaced the artificial preservative sorbic acid with a natural preservative called natamycin. Natamycin performs the same role as sorbic acid, fighting mold.

Bacterial growth is the main reason cheeses go bad, so the preservatives in American cheese help it last a long time in the fridge. The expiration date printed on packages is generally about five to six months after the cheese is produced, but the cheese can often be safely used beyond this date.

To further extend the shelf life of American cheese, it can be frozen. When properly stored, it will maintain its best quality for about eight months but will remain safe beyond that time.

Kraft cheese slices

The long shelf life of Kraft cheese slices can be attributed to the preservatives used in the cheese, such as natamycin, which fights mold, and sodium citrate, which improves meltability. The expiration date on Kraft Singles is generally about five to six months after production, but the cheese can often last beyond this date. Unopened slices can last up to two months past the printed date, while opened slices should be used within a week. However, if the cheese shows signs of spoilage, such as a slimy texture or a sour odour, it should be discarded, regardless of the expiration date.

The high level of processing and preservatives in Kraft cheese slices means they will likely last much longer than the recommended expiration date, as bacteria struggle to grow in such an environment. This is supported by several anecdotal reports of Kraft Singles lasting for a year or more without showing any signs of spoilage.

While Kraft cheese slices may not provide the same culinary experience as "real" cheese, their long shelf life and meltability make them a convenient option for certain dishes, such as cheeseburgers and mac and cheese.

Freezing American cheese

Freezing is a great way to extend the shelf life of American cheese. While it may not be the best option for fancy cheese boards, it is a good way to preserve your cheese for cooking and baking.

Processed cheese slices like American cheese can be frozen, especially if they are unopened. To freeze prepackaged sliced cheese, place the package in a freezer bag and then into the freezer. Deli-sliced cheese requires a little more preparation. First, place a piece of parchment paper between each slice of cheese. Then, wrap the cheese in freezer paper, taping it shut before placing it in a freezer bag or freezer-safe container.

Freezing cheese will likely change its texture, but this is not an issue if you plan to melt the cheese. Freezing cheese should not change its flavour. However, if the cheese is poorly packaged, it may pick up the smells of your freezer.

Frozen cheese should be used within two to three months and should be thawed in the refrigerator before use. It is important to ensure that frozen cheese is completely thawed before use to avoid shattering. Once thawed, do not refreeze.

How to tell if American cheese has gone bad

American cheese is a processed cheese, and while it has a relatively long shelf life, it can still go bad. Here are some ways to tell if American cheese has gone bad:

Check for mould

If you spot mould on soft American cheese, it's best to throw it away. For hard cheeses, if you find mould, you can cut off the mouldy part and the area surrounding it, as long as the mould hasn't spread to the entire cheese. Make sure to carefully inspect the rest of the cheese for any mould before consuming it.

Colour changes

If your cheese has changed colour, it could indicate an issue with the milk. If it starts to smell like rancid milk, discard it.

Smell

While some cheeses have a strong odour, they shouldn't smell like sweat, chlorine, or ammonia. If your American cheese has an unusual odour, it's best to throw it out.

Expiry date

Most packaged cheeses have a "best-by" date. While the cheese may still be safe to eat after this date, it's always a good idea to inspect it before consuming.

Texture

If your American cheese has dried out or hardened, it has likely passed its prime and should be discarded.

American cheese's shelf life

American cheese is meant to have a long shelf life. It is a processed cheese, which means it is made from natural cheese that has been heated and blended with emulsifiers to give it a smooth texture and better meltability. This process also makes it less prone to spoilage from bacteria.

The shelf life of American cheese depends on how it is stored. Unopened sliced American cheese can be kept in its original packaging in the refrigerator. It will last 2 to 3 weeks beyond the sell-by date and up to 6-8 months from the date of purchase, though the quality may deteriorate after the initial 2-3 weeks. To extend the shelf life further, it can be frozen. When properly stored in the freezer, American cheese will maintain its best quality for about 8 months, but it can be kept safely beyond this time.

Once the packaging is opened, American cheese should be consumed within a week. If it is left out at room temperature, it will only last for about two hours.

To maximise the shelf life of American cheese, it should be stored in the refrigerator at a temperature below 40°F (4°C). It should be wrapped in wax, parchment, or cheese paper, or sealed tightly in plastic wrap or a resealable plastic bag. It should not be wrapped in tight, non-porous material such as plastic wrap, as this can dry out the cheese.

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