How is lactose-free milk made?

In this brief guide, we are going to answer the question “how is lactose-free milk made” with an in-depth analysis of how lactose-free milk is made from regular milk. Moreover, we are going to discuss the taste profile and nutritional profile of lactose-free milk.

So without much ado, let’s dive in and figure out more about it.

How is lactose-free milk made?

Lactose-free milk is made by the addition of lactase enzymes in regular milk. 

The process of making lactose-free milk involves several steps. Initially, the milk is pasteurized and cooled to a temperature of 5 °C. 

Enzymes are then introduced into the milk within a holding tank, and the milk is left undisturbed overnight. The duration of this process is determined by the desired degree of hydrolysis, typically targeting 70% or 100% breakdown of lactose.

Once the desired level is achieved, the milk undergoes reheating to deactivate the enzymes, a procedure known as ultra-pasteurization. Following this, the milk is packed into retail containers. 

The additional heat treatment during ultra-pasteurization significantly extends the shelf life of lactose-free milk compared to regular pasteurized milk. (1)

Is there an alternate method of making lactose-free milk?

Yes, an alternative method exists using UHT (Ultra High Temperature) treatment for sterilizing the milk. In this process, the enzyme is first sterilized through ultra-filtration and then combined with UHT milk just before aseptic packaging. 

Only a small quantity of enzyme is necessary to achieve nearly complete hydrolysis during 7 to 10 days of milk storage at room temperature. If the milk is stored by the producer for one month before distribution, even less enzyme is required.

This alternative process offers advantages such as reduced enzyme and processing costs. However, it requires the enzyme to be exceptionally pure and devoid of protease activity to prevent any damage to the milk proteins during storage. (1)

What is the nutritional value of lactose-free milk?

Lactose-free milk shares a nutritional profile similar to that of regular milk, making it a valuable beverage choice. It is rich in protein and calcium, essential for preventing osteoporosis and maintaining muscle mass.

Moreover, it provides a range of vital elements including riboflavin, phosphorus, vitamins A and B12, potassium, magnesium, and zinc. (2, 3)

Is lactose-free milk good for your health?

Regular consumption of lactose-free milk gives similar benefits to that of regular milk, it offers multiple advantages for overall well-being. Its high calcium content, combined with the presence of vitamin D, helps safeguard against osteoporosis.

The ample protein in milk contributes to the development and preservation of muscle mass. Furthermore, milk contains oligosaccharides that act as nutrients for beneficial bacteria in the colon, promoting a healthy intestinal microbiota.

Milk’s significant presence of vitamin B complex supports optimal neurological functioning. The amino acids present in whole milk possess anti-hypertensive properties, potentially assisting in regulating high blood pressure. 

Additionally, whole milk retains the naturally occurring fat-soluble vitamins A, E, K, and D found in milk fat. In contrast, skim milk lacks these essential nutrients due to its fat-free nature.(2, 3)

Is lactose-free milk suitable for lactose intolerant people?

Yes. Lactose intolerance (LI) is a condition that affects the mucosa of the small intestine, impairing the digestion and absorption of lactose from the diet. This occurs either due to low activity or non-production of the lactase enzyme, β-D-Galactosidase, in the body. (3)

What happens if lactose intolerant people consume regular milk?

LI manifests with various symptoms including flatulence, abdominal discomfort, bloating, feelings of swelling, nausea, borborygmus (stomach rumbling), vomiting, constipation, watery diarrhea with acidic stools, perianal roasting, dehydration, metabolic acidosis, and in severe cases, malnutrition.

The occurrence of diarrhea in LI is attributed to the lack of lactose absorption or utilization in the small intestine. This leads to increased local osmolarity, attracting water and electrolytes to the mucosa, resulting in intestinal dilation and accelerated transit, which further exacerbates malabsorption.

As lactose accumulates in the colon, it undergoes fermentation by the intestinal microbiota, producing short-chain organic acids such as acetic, butyric, and propionic acid, as well as gasses like methane, carbon dioxide, and hydrogen. 

These gasses contribute to symptoms such as flatulence, abdominal distension, and pain. Additionally, the production of organic acids leads to the acidification of feces, causing them to become liquid and resulting in increased abdominal distension and perianal hyperemia.(3)

Does lactose-free milk last longer?

Yes. The additional heat treatment extends the shelf-life from about 15 days (for normal pasteurized milk) to 35±45 days. 

The enzyme can also be added to milk prior to conventional pasteurization but the resulting shelflife is lower than that of the ultra pasteurized product.

The lactose free milk produced by  Ultra-high temperature processing (UHT) treatment has a shelf-life of up to 6 months. (1)

Other FAQs about Milk that you may be interested in.

Does Milk Make You Stronger

Does Milk Make Your Teeth White?

Does Milk Stain?


In this brief guide, we answered the question “how is lactose-free milk made” with an in-depth analysis of how lactose-free milk is made from regular milk. Moreover, we discussed the taste profile and nutritional profile of lactose-free milk.


  1. Mahoney, R. R. Enzymes Exogenous To Milk In Dairy Technology | Beta-d-Galactosidase. Encyclopedia of Dairy Sciences, 907–914. 2002.
  2. Pereira, P. C., & Vicente, F.  Milk Nutritive Role and Potential Benefits in Human Health. Nutrients in Dairy and Their Implications on Health and Disease, 161–176. 2017.
  3. Silva, A. R. A., Silva, M. M. N., & Ribeiro, B. D.  Health Issues and Technological Aspects of Plant-based Alternative Milk. Food Research International, 108972. 2020.

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