What is the Difference Between Sour Milk and Spoiled Milk

The main difference between sour milk and spoiled milk is that sour milk is perfectly safe for consumption while consumption of spoiled milk can result in digestive symptoms like vomiting, diarrhoea, and abdominal cramping.

Sour milk is a dairy product produced from the acidification of milk while spoiled milk is milk that has gone bad naturally via bacteria infestation. Both these types of milk have a sour and acidic taste. But, sour milk is not the same as spoiled milk.

Key Terms Covered

1. What is Sour Milk
     – Definition, Characteristics
2. What is Spoiled Milk
     – Definition, Characteristics
3. What is the Difference Between Sour Milk and Spoiled Milk
    – Comparison of Key Differences

Key Terms

Sour Milk, Spoiled Milk

What is Sour Milk

Sour milk, also known as soured milk, is a dairy product we can obtain from the acidification of milk. We can acidify the milk either by fermentation or by adding an acid like lemon juice or vinegar. The acid causes milk to coagulate and thicken; this inhibits the growth of harmful bacteria and enhances the milk’s shelf life. Furthermore, the process of acidification gives the milk a characteristic tartness. Sour milk is similar to buttermilk since both have a slightly sour and acidic taste. Moreover, these are substitutes for each other. Sour milk is also a good substitute for yoghurt and sour cream.

Figure 1: Sour Milk

However, sour milk is not the same as spoiled milk, although both have a sour taste.  Spoiled milk is milk that has gone bad naturally. Such milk is unsafe to use.

What is Spoiled Milk

Milk is a food product that gets spoiled easily. It is easily susceptible to bacteria infestation. This infestation results in changes in the flavour, quality, and texture of milk. As the milk begins to get spoiled, it emits a rancid odour, which is hard to miss. This odour gets stronger with time. The natural sweetness of fresh milk also changes into a slightly acidic or sour flavour. There is also a change in the appearance and texture of the milk – the milk develops a chunky and slimy texture and gets a yellow colour.

Figure 2: Fresh Milk

Drinking spoiled milk can adversely affect your digestive system and result in digestive symptoms like vomiting, diarrhoea, and abdominal cramping. You don’t have to worry if you just accidentally sip a few drops of spoiled milk, but you should avoid drinking large or even moderate quantities of spoiled milk.

If the milk is very old and has begun to curdle, become slimy, or grow mould, you should throw it out. However, if it’s only a little off and has a slightly acidic taste, there are few ways to use it. You can use it for baked goods as a substitute for regular milk or buttermilk. You can also use it thicken soups and stews. But you should note that here we are referring to pasteurized milk that has become spoilt, not raw milk. The process of pasteurization kills most harmful strains of bacteria that cause foodborne illness, including Salmonella E. coli, and Listeria.

Difference Between Sour Milk and Spoiled Milk

Definition

Sour milk is a dairy product produced from the acidification of milk while spoiled milk is milk that has gone bad naturally via bacteria infestation.

Safety

Sour milk is perfectly safe for consumption, while the consumption of spoiled milk can result in digestive symptoms like vomiting, diarrhoea, and abdominal cramping.

Process

Sour milk produced either through fermentation or through adding an acid like vinegar or lemon juice, while spoiled milk forms when milk goes off naturally via bacteria infestation.

Conclusion

Sour milk is a dairy product produced from the acidification of milk while spoiled milk is milk that has gone bad naturally via bacteria infestation. The main difference between sour milk and spoiled milk is that sour milk is perfectly safe for consumption while consumption of spoiled milk can result in digestive symptoms like vomiting, diarrhoea, and abdominal cramping.

Reference:

1. Hill, Ansley. “Spoiled Milk: Risks and Beneficial Uses.” Healthline, Healthline Media, 21 Aug. 2019, Available here.
2. “Soured Milk.” Wikipedia, Wikimedia Foundation, 19 Aug. 2020, Available here.

Image Courtesy:

1. “Kysle mlieko” By Maciarka – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “518067” (CC0) via Pixabay