Can condensed milk go bad? (3 Factors that make a difference)

In this brief guide, we will answer the question, can condensed milk go bad? We will discuss the reasons that make condensed milk go bad or prevent it from going quickly. We will shed light on different types of condensed milk and their respective shelf lives.

Can condensed milk go bad?

Yes. Both unsweetened and sweetened condensed milk have the potential to go bad due to the continuous risk of post-processing contamination in all sterilized milk products. 

This risk arises from various factors such as micro leaks in the cans or during the filling process. Contamination sources can include raw milk, low-quality sugar, and unhygienic factory conditions, such as improperly cleaned and sanitized equipment and filling machines. (1) 

How does condensed milk go bad?

Contamination of condensed milk can occur through micro leaks in the cans or during the filling process. One significant cause of product defects is the growth of Bacillus Stearothermophilus, a thermophilic spore-forming bacteria, in the evaporator. 

This issue is often linked to prolonged running time of the evaporator or improper equipment cleaning, leading to a notable spore count in the concentrated milk. 

The sterilization process may not entirely inactivate these spores, and in tropical countries where storage temperatures can exceed 40°C, the residual spores may germinate and grow, further compromising the product’s quality. (1)

The high sugar content in sweetened condensed milk makes it less susceptible to spoilage, but it remains vulnerable to osmophilic organisms. To ensure its preservation, maintaining strict plant and manufacturing hygiene is crucial for success. (2)

What is condensed milk shelf life?

Both sweetened condensed milk and evaporated milk can achieve an adequate keeping quality of up to 12 months. However, the longevity of their shelf life greatly relies on the storage conditions employed. 

When stored at temperatures above 25°C, both the aging process and associated physical and sensory defects manifest more rapidly in the product. 

In the case of recombined products, their shelf-life stability, without significant deviations from the original appearance and quality, is reduced by approximately half compared to fresh-milk products. (2)

Is there a difference between condensed milk and sweetened condensed milk?

Yes. There are some major differences between these products.

Sweetened condensed milk. 

To produce sweetened condensed milk, sugar is added to whole milk, and the water is subsequently removed, reducing the milk to approximately half of its original volume. 

This condensed mixture is then packaged in cans or other containers without undergoing sterilization, as the added sugar serves as a natural preservative. 

To meet international standards, sweetened condensed milk must have a minimum milk fat content of 8% and a minimum milk solids content of 28%.

Unsweetened condensed milk.

Evaporated milk is created by evaporating the water from milk without adding any sugar or other preservatives. The resulting product is then canned and subjected to heat sterilization at temperatures ranging from 118°C to 122°C for several minutes. 

Alternatively, it can be packed in other sterilizable containers. To comply with international standards, evaporated milk must contain a minimum milk fat content of 7.5% and a minimum milk solids content of 25.0%. (2)

How to store condensed milk to maintain its quality?

To maintain the quality of condensed milk during storage for an extended period, specific conditions are crucial. One of the major factors impacting shelf life is the storage temperature. Typically, condensed milk and evaporated milk (EM) are stored at temperatures around 10–15°C.

However, extremely low temperatures, such as 0°C or below, can result in sugar separation within condensed milk, leading to a sand-like texture caused by the formation of large lactose crystals. 

While low storage temperatures can increase the viscosity of the product, which may be beneficial to some extent, it can also affect the overall body and texture characteristics.

To preserve the product further, it’s essential to maintain low humidity levels (below 50%) in the storage space to prevent spoilage of cans and labels. Additionally, inverting the cans during storage helps minimize fat separation in EM, contributing to a better-quality product over time. (1)

What are the signs of sweetened condensed milk spoilage?

The main signs of spoilage are:

Mold buttons: 

This defect arises during storage due to mold contamination. It appears as small reddish-brown pieces of curd, forming on the surface of the product, leading to localized coagulation.

Storage at high temperatures promotes the growth of this organism, and it may contaminate the milk during the concentration process.

Preventing this defect requires meticulous cleaning and maintenance of dairy equipment. As the organism does not thrive at low temperatures, storing condensed milk at a lower temperature will effectively avoid this problem.

Gassy fermentation/bloats: 

Cans and barrels of condensed milk can develop gas, leading to bulging or bursting. The formation of gas is often due to gas-producing yeasts, which are responsible for various gaseous fermentations. 

This contamination can originate from different sources, including raw milk, low-quality sugar, or unhygienic conditions within the factory (such as improperly cleaned and sanitized equipment and filling machines).

Bacterial thickening: 

During storage, condensed milk undergoes a gradual thickening process due to the presence of microorganisms that produce rennet-like enzymes. However, these microorganisms are effectively eliminated during the preheating process.

An optimal sugar ratio plays a vital role in inhibiting the growth of these microorganisms. Furthermore, storing the condensed milk at low temperatures also aids in reducing bacterial thickening, contributing to the preservation of its desired consistency. (1, 2)

What are the health implications of consuming spoiled condensed milk?

Consuming spoiled condensed milk can lead to food poisoning, presenting symptoms such as nausea, vomiting, diarrhea, abdominal cramps, fever, weakness, headaches, and dehydration.

Typically, mild food poisoning may last for about a day or two, while more severe cases can persist for up to 10 days.

If the symptoms worsen or if diarrhea and vomiting continue for more than 3 days, it is crucial to seek medical assistance promptly. (3)

Other FAQs about Milk that you may be interested in.

Do Oreos Contain Milk

Does Oat Milk Make You Poop?

Does McDonald’s Have Almond Milk


  1. Kalyankar, Shrikant & Deshmukh, Mahesh & Khedkar, Chandraprakash.  Condensed milk. 2016.
  2. Hess, H. J. CONDENSED MILK. Encyclopedia of Food Sciences and Nutrition, 1574–1581. 2003.
  3. Lu, M., & Wang, N. S.  Spoilage of Milk and Dairy Products. The Microbiological Quality of Food, 151–178. 2017.

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