How to check adulteration in milk?


Milk adulteration is a common issue that poses health risks and compromises the quality of this essential dietary staple. Adulteration involves adding water, chemicals, or other substances to milk to increase volume or mimic the appearance of pure milk.

Knowing how to check adulteration in milk, helps ensure that the milk you consume is safe and nutritious. This guide covers simple home tests and advanced laboratory methods to detect milk adulteration.

Common Adulterants in Milk

1. Water

Water is the most common adulterant added to milk to increase its volume. While water itself is not harmful, its addition dilutes the milk’s nutritional content, reducing its value.

Furthermore, if the water is contaminated, it can introduce harmful pathogens into the milk, leading to serious health issues such as gastrointestinal infections.

2. Starch

Starch is added to milk to thicken it and mimic the consistency of higher-fat milk. The addition of starch can lead to digestive problems, particularly for infants and young children, who may experience bloating, constipation, and stomach cramps.

3. Detergents

Detergents are added to milk to create froth and give it a whiter appearance, mimicking the look of pure milk.

Detergents can cause a range of health issues, including nausea, vomiting, and diarrhea. Long-term consumption can damage the gastrointestinal tract and lead to more severe health problems.

4. Urea

Urea is added to increase the nitrogen content of milk, which can falsely enhance the protein content reading.

Excessive intake of urea can cause kidney damage and other metabolic disturbances. It can lead to symptoms such as headaches, nausea, and vomiting.

5. Formalin

Formalin, a solution of formaldehyde in water, is used to preserve milk and extend its shelf life.

Formalin is highly toxic and carcinogenic. Its consumption can cause severe health issues, including respiratory problems, and gastrointestinal discomfort, and long-term exposure can increase the risk of cancer.

6. Sugar

Sugar is added to milk to mask the taste of dilution and poor quality. Excess sugar intake can lead to weight gain, dental problems, and increased blood sugar levels, posing risks for diabetics and contributing to obesity and metabolic syndrome.

7. Salt

Salt is added to increase the density and improve the taste of milk. High salt intake can lead to hypertension and cardiovascular issues, making it particularly dangerous for individuals with heart conditions.

8. Synthetic Milk

Synthetic milk is created using a mixture of water, chemicals, soap, and other substances to imitate real milk.

Consumption of synthetic milk can lead to serious health problems, including gastrointestinal issues, neurological damage, and organ dysfunction due to the harmful chemicals used in its production.

Simple Home Tests for Milk Adulteration

To check the adulteration of milk at home, one can opt for these three methods such as water adulteration test, starch adulteration test, and detergent test. These adulteration tests are easy to perform. Every household person should have this basic knowledge on how to check the adulteration of milk.

1. Water Adulteration Test

To check if water has been added to milk:

  1. Place a drop of milk on a polished vertical surface, like a glass or a marble slab.
  2. Observe the behavior of the drop.
  3. Pure milk leaves a trail or streak as it flows down, while adulterated milk with added water will flow down without leaving a mark.

2. Starch Adulteration Test

To detect the presence of starch:

  1. Boil 5 ml of milk in a test tube or a small container.
  2. Allow it to cool, then add 2-3 drops of iodine solution (commonly found in pharmacies).
  3. If the solution turns blue, it indicates the presence of starch.

3. Detergent Adulteration Test

To find out if detergent is present:

  1. Shake 5-10 ml of milk in a test tube or a container.
  2. If the milk forms dense lather, it may contain detergent.

4. Synthetic Milk Test

Synthetic milk is made by mixing chemicals and other substances:

  1. Rub a small amount of milk between your fingers.
  2. Pure milk feels smooth, while synthetic milk feels soapy due to the presence of synthetic substances.

5. Urea Adulteration Test

Urea is sometimes added to milk to increase protein content:

  1. Mix half a tablespoon of milk with a tablespoon of soybean powder.
  2. After 5 minutes, dip a red litmus paper into the mixture.
  3. If the paper turns blue, it indicates the presence of urea.

Advanced Laboratory Methods

1. Lactometer Test

A lactometer measures the specific gravity of milk:

  1. Pour milk into a cylinder and immerse the lactometer.
  2. The reading should typically be between 1.028 to 1.032. A lower reading suggests dilution with water.

2. Fat Content Analysis

Milk fat can be analyzed using a Gerber method or a butyrometer:

  1. A sample of milk is mixed with sulfuric acid and amyl alcohol and then centrifuged.
  2. The fat content is measured based on the separated fat layer.

3. SNF (Solid-Not-Fat) Test

This test measures the non-fat solids in milk, including proteins, lactose, and minerals:

  1. The SNF content is calculated using the formula: SNF = (LR/4) + (0.2 x Fat%) + 0.36, where LR is the lactometer reading.
  2. Low SNF values indicate possible adulteration with water or other substances.

4. Chromatography and Spectroscopy

These advanced techniques are used in laboratories to detect chemical adulterants:

  1. Chromatography separates different components of milk.
  2. Spectroscopy identifies specific adulterants based on their spectral signatures.


Detecting milk adulteration is crucial for ensuring the safety and quality of the milk you consume. While simple home tests can provide quick indications of common adulterants, advanced laboratory methods offer precise and reliable results. Regular testing and awareness can help protect against the health risks associated with adulterated milk.

Spread the love

Leave a Comment