How to preserve m&ms

In this brief guide, we are going to answer the question “how to preserve m&ms” and discuss the different methods used to preserve m&ms.

How to preserve m&ms 

M & Ms are confectionery products that are coated mouth-sized pieces of chocolate. They are produced by using a process called panning. Pan coating is the build up of a center (kernel or corpus) with a liquid or liquid and powder substances with multiple layers or continuous phases, which are set, hardened or dried to smooth or pearled surface and often finished with a sealant and or a polishing agent, utilizing rotating pans or drums creating a fluid bed (1).

M&ms are preserved by:

  • Storing in a cool dry place with low temperature and moisture
  • Refrigerating
  • Freezing

M&ms are popular chocolate candies with a colorful casing.  M&ms can be eaten even after their best before date and m&ms stored in the pantry will last 6 to 12 months past their best by date. 

There are different flavors of m&ms made with different ingredients. Some m&ms preserve better than others. Some popular m&m flavors include regular chocolate, peanut butter, almond, and mint. M&ms are also used to decorate cakes and desserts.

How to identify if m&ms are good to eat?

M&ms have a best before date instead of expiry date. This means that the m&ms can be eaten even after the date recommended by the manufacturer. M&ms past their best before date may not taste as good as new ones.

Color: Faded color. New m&ms have brightly colored casings. With time, the color will fade. 

Texture: If m&ms have been stored at a warm temperature, they will melt. The outer casing may split open and the candies will be soft to the touch. Melted m&ms can still be eaten. They can also be substituted for cooking chocolate in a dessert recipe.

Appearance: White dots forming on the outer casing indicate that the chocolate is getting older and drying out. You can eat m&ms with white dots, but they won’t taste as good. 

Taste: If you are unsure whether the m&ms have gone bad, try tasting one. If it tastes good, the m&ms are good to eat.

How to store m&ms properly?

Shelf life is the length of time that a food maintains an acceptable level of quality. The end of shelf life for a food product is characterized by the presence of undesirable physicochemical qualities or microbial levels (2). 

Storing m&m under proper conditions can prolong their shelf-life. When storing m&ms, consider the storage temperature and moisture. Both high temperatures and high moisture will cause the m&ms to melt and the coloring of the outer casings will runoff. It is also important to select the correct storage container and store m&ms away from sunlight.

Temperature: M&ms have a low melting point so they must be stored at low temperature. High heat will melt the outer covering as well as the chocolate inside. The best temperature to store m&m is between 65-75 °F. An increase of 10°C generally causes a doubling of reaction rates. Fluctuating temperatures generally also enhance physico-chemical changes and cycling temperatures promote more rapid degradation than holding at constant temperatures (2).

Moisture: M&ms must be stored at low moisture conditions. When they are refrigerated or frozen, always make sure to place them inside an airtight container. High moisture will damage the outer casing and cause the colors to leach. Moisture affects both physical and chemical attributes that determine shelf life, including crystallization, glass transition, and rate of enzymatic or non-enzymatic reactions. Additionally, the water activity of a food system affects the growth of bacteria, mold, and yeasts that may cause spoilage or safety concerns (2).

Storage container: always try to store m&ms in their original packaging. This way you can keep track of the best by date. If m&ms are transferred into new packaging, make sure they are kept in an air-tight container. Always mark the expiry date on the container. The packaging materials can preserve the environment within the package by being selectively permeable to molecules such as oxygen or water (2).

Lighting: Always store m&m away from sunlight. If kept in the kitchen, store them inside a dark cupboard. keep light out it will slow the rates of some reactions in the food (2).

How to preserve m&ms by refrigerating and freezing

There are conflicting ideas about refrigerating and freezing m&ms. 

Freezing will prolong the shelf-life of m&ms by about 6 months but it also changes the texture of the chocolate. After all, refrigerated or frozen chocolate will never taste as good as fresh chocolate. Still, if you are living in a warm climate with room temperature 35 C or higher, refrigerating or freezing m&ms is a good way to keep them from melting. Storing chocolate at freezing temperatures will better preserve the volatile compounds of the chocolate as well as its texture, when compared to chocolate stored at room temperature or with those which suffer temperature fluctuations during storage (3).

Freezing m&ms is easy. 

  • Place the m&ms in an airtight container or a ziplock bag. If possible, use vacuum packaging to remove all the air.
  • Label the container with the expiry date.
  • Freeze or refrigerate them.

How to use refrigerated and frozen m&ms

Refrigerated and frozen m&ms will be hard to eat. It is best to allow them to reach room temperature before eating. If you are using refrigerated or frozen m&ms as cooking chocolate, this won’t be an issue. You can heat the chocolate straight from the fridge.

How to use m&ms in cooking

If you have a lot of m&ms and can’t figure out what to do with them, you can always try to incorporate them in a dessert. Cookies, brownies, cupcakes are just a few of the desserts that you can make using your extra m&ms.

A recipe for m&m chocolate m&m cookies can be found here.

Other FAQs about Chocolates that you may be interested in.

Can chocolate get moldy?

Can you give chocolate to dogs?

Can you substitute chocolate chips for baking chocolate?


In this brief guide, we answered the question, “how to preserve m&ms”. We also looked at how to identify if m&ms are good to eat and how to use m&ms in cooking.

If you have any questions or comments, please let us know.


  1. Beckett, Steve T., ed. Industrial chocolate manufacture and use. John Wiley & Sons, 2011.
  2. Ergun, R., R. Lietha, and Richard W. Hartel. Moisture and shelf life in sugar confections. Crit rev food sci nutr, 2010, 50, 162-192.
  3. Nightingale, Lia M., Keith R. Cadwallader, and Nicki J. Engeseth. Changes in dark chocolate volatiles during storage. J agri food chem, 2012, 60, 4500-4507.