Digging Deeper: Pasteurization

By The Dirt To Dinner Team June 19, 2024 | 7 MIN READ | UPDATED FROM JULY 2017

The Dirt:

Milk is a vehicle for many nutrients. It is a healthy source of fat, calcium, protein, amino acids, vitamins, and minerals. What role does pasteurization play in the production of milk? And does this process do more harm than good?

Global Food


Digging Deeper: Pasteurization

Cattle & Dairy


Food Production

Food Technology

Health and Nutrition

By The Dirt To Dinner Team June 19, 2024 | 7 MIN READ | UPDATED FROM JULY 2017

The Dirt:

Milk is a vehicle for many nutrients. It is a healthy source of fat, calcium, protein, amino acids, vitamins, and minerals. What role does pasteurization play in the production of milk? And does this process do more harm than good?

In the past, some of us drank fresh, raw milk every day. But these days, several factors make raw milk an untenable option, including dairy industry consolidation, food safety concerns, and longer transportation times.

Since milk needs to be packaged and delivered to a grocery store or corner market, it may take several days before it hits your glass. For milk to safely survive the journey from cow to carton, it gets pasteurized, a process that keeps milk safe and lasting longer in your refrigerator.

pastuerization, Digging Deeper: Pasteurization

Pasteurization is the process of heating a substance to kill pathogens, such as listeria, E. coli, salmonella, and the highly-pathogenic avian flu.

Dairy producers pasteurize milk to make it safe for consumers, as well as maintaining its safety during transport and extended storage times. If you drink raw milk straight from a cow, without treating it, you put yourself at great risk.

Some believe this process makes milk harder to digest and is an unnecessary procedure that denies our bodies of nutrients destroyed in the processing. Let’s take a look at this first.

Does Pasteurization Make Milk Harder to Digest?

Many proponents of raw milk products believe that pasteurized milk causes gut inflammation from not properly breaking down these denatured protein compounds.

Scientifically, the heat treatment disrupts the hydrogen bonds in a protein molecule and causes the bonds to be “disrupted.” For reference, when you cook an egg, the proteins also denature.

So, while heating raw milk can cause denaturation of protein, this has only proven to potentially affect immunocompromised patients.

Additionally, how your body digests denatured protein depends entirely on the amount of heat exposure the proteins have had. Typical pasteurization methods generate very few denatured proteins.

Let’s take a closer look at the most common ways to pasteurize milk and milk products.

Pasteurization Methods


Also known as flash pasteurization, this method heats up the milk to 280 degrees for 4-5 seconds. Because the temperature of the milk exceeds 150 degrees, it is possible for the proteins to “denature,” or change from their original structure. Essentially, the heat can cause the protein compounds to break down. It is also argued that this process kills off some of the good bacteria present in raw milk.

pastuerization, Digging Deeper: Pasteurization

High-temperature pasteurization

This is the most commonly used pasteurization technique. This process heats up milk to 161 degrees for 15 seconds.

Like flash pasteurization, some of the micro-life present in raw milk will be killed off through HT pasteurization. Additionally, the proteins in HT-treated milk may experience some denaturation. Heat treatment aside, milk remains a nutrient dense food.

Low-temperature pasteurization

LT heats raw milk to 145 degrees for 30 minutes before chilling it rapidly. Like HT and ultra pasteurization, this process can also kill off some of the probiotics present in raw milk. But, it is argued that LT pasteurization helps maintain milk’s protein quality.

While this process does not “denature” proteins, it can cause protein aggregation, whereby the compounds accumulate and clump together, making the proteins harder to digest. These proteins are harder to digest than its denatured counterpart, making consumption especially challenging for immune compromised or extremely allergic individuals.

Raw or unpasteurized

These products have not been heat-treated and are at much greater risk of carrying harmful pathogens. They also have a significantly shorter shelf life, which contributes to food waste if not consumed within a few days of its production.

Even more options

While heat-treating raw milk will destroy some of its beneficial properties, it’s a high price to pay if it’s contaminated with dangerous pathogens. If you still want to enjoy raw milk for its nutrients, consider purchasing products from dairy companies that add active cultures and probiotics that were affected during heat processing.

pastuerization, Digging Deeper: Pasteurization

One such company taking proactive steps to protect your digestive system is Fairlife. Fairlife milk is flash pasteurized and then ultra-filtered to concentrate the protein content, sterilize the milk, and remove lactose – or milk sugars –  from the final product.

This way, those who suffer from lactose intolerance and/or have a hard time digesting denatured milk proteins can enjoy this dairy product with minimal to no effects.

What about cheeses?

Cheese is another important food when it comes to pasteurization. The U.S. Food and Drug Administration mandates that any cheese produced from raw milk must be held or aged for 60 days and kept consistently at 35-degrees Fahrenheit before it can be sold commercially. This helps ensure that foodborne pathogens are no longer present in the food, as they cannot survive in an environment after 60 days.

pastuerization, Digging Deeper: Pasteurization

Additionally, treating the cheese with salt and curing the rind can also protect from potentially dangerous bacteria, viruses and molds. Like milk, pasteurized cheese can be treated at either a high temperature (174 degrees for roughly 20 seconds) or low temperature (149 degrees for 30-40 seconds).

When you think of pasteurization, you undoubtedly think of milk! However, many other foods that are heat treated, as well. Almonds, sauerkraut, and some kinds of vinegar are pasteurized to sanitize the food and kill harmful bacteria. The pasteurization process keeps consumers safe, so before you dismiss a pasteurized product, also consider what it may be protecting you from.

The Bottom Line:

Do not fear pasteurization! Despite the elimination of some good bacteria, milk is a safe, nutrient-dense food. Pasteurization protects you from all sorts of dangerous pathogens.