How do you take lactose out of dairy products?

About 65% of the global population has a reduced ability to digest lactose, the natural sugar found in milk. Fortunately, several methods can be used to take lactose out of dairy products, from advanced industrial techniques to simple at-home solutions using a lactase enzyme.

Quick Summary

Lactose can be removed or reduced in dairy products via enzymatic hydrolysis with lactase, membrane filtration, or fermentation. These methods cater to both large-scale production and simple at-home preparation.

Key Points

• Enzymatic Hydrolysis: The most common method involves adding lactase enzyme to dairy, which breaks down lactose into more digestible sugars, glucose and galactose.

• DIY Lactase Drops: You can easily make your own lactose-free milk at home by purchasing lactase enzyme drops and letting them act on the milk in the refrigerator for at least 24 hours.

• Filtration Techniques: Industrial production often uses advanced membrane filtration to physically separate a portion of the lactose, which can result in a taste profile closer to regular milk.

• Fermentation Reduces Lactose: Fermented dairy products like yogurt and kefir are naturally lower in lactose because the cultures consume the sugar during processing.

• Naturally Low-Lactose Options: Hard, aged cheeses like parmesan and cheddar are typically very low in lactose due to the aging and whey-draining process.

• Doesn't Affect Milk Allergy: Removing lactose does not eliminate milk proteins. This is not a solution for individuals with a milk protein allergy.

Understanding Lactose and Lactase

Before delving into the methods of lactose removal, it's essential to understand the sugar itself and the enzyme required to digest it. Lactose is a disaccharide, meaning it is a sugar composed of two smaller sugar molecules: glucose and galactose.

The Role of Lactase

In a person with no digestive issues, the enzyme lactase is produced in the small intestine. Its function is to break down lactose into its two simple, easily digestible sugar components, glucose and galactose. For individuals with lactose intolerance, this enzyme is either deficient or completely absent, leaving undigested lactose to travel to the large intestine. There, gut bacteria ferment the sugar, causing uncomfortable symptoms like bloating, gas, and abdominal pain.

Industrial Methods for Removing Lactose

Commercial producers of lactose-free dairy utilize sophisticated, large-scale techniques to ensure a consistent, high-quality product.

Enzymatic Hydrolysis

This is the most common and straightforward commercial method. The process involves adding the lactase enzyme to milk after pasteurization. The enzyme then breaks down the lactose over time into glucose and galactose. This process increases the milk's sweetness because glucose and galactose are sweeter than the original lactose molecule. This is a cost-effective and simple method for producing lactose-free milk with a slightly sweeter taste profile. The final product is then heat-treated (often ultra-pasteurized) to inactivate the enzyme and ensure a longer shelf life.

Membrane Filtration

Some manufacturers use ultrafiltration (UF) or nanofiltration (NF) techniques to physically separate the lactose from the other components of milk. In a typical process, milk is passed through filters that remove about half of the lactose. This initial reduction is often followed by enzymatic hydrolysis of the remaining lactose to reach the required 'lactose-free' threshold. This combined approach is often used to produce a milk with a more neutral, less-sweet taste profile, more closely resembling the flavor of regular milk.

Combined Methods

High-end commercial processes, pioneered by companies like Valio in Finland, combine filtration with enzymatic hydrolysis to achieve optimal results. Milk is first ultrafiltered to remove a portion of the lactose, then nanofiltered to further separate and concentrate the lactose. The lactose-depleted stream is then rejoined with the original milk minerals before a final dose of lactase is added to hydrolyze any remaining sugar. This multi-step process allows for precise control over sweetness and mineral content.

How to Take Lactose Out of Dairy Products at Home

For those who prefer a more hands-on approach, there are two primary methods for reducing or eliminating lactose from dairy at home.

Using Lactase Enzyme Drops

The simplest DIY method involves adding liquid lactase drops directly to a container of milk.

1. Purchase lactase enzyme drops from a pharmacy or online retailer.
2. Add the recommended number of drops per quart or liter of milk, as specified on the product's packaging.
3. Stir or shake the milk thoroughly to mix in the enzyme.
4. Refrigerate for at least 24 hours to allow the enzyme time to break down the lactose. Some recipes suggest longer for maximum lactose reduction. The longer it sits, the sweeter the milk will become.

Fermenting Dairy Products

Naturally occurring bacteria in fermented dairy products like yogurt, kefir, and hard cheeses consume lactose during the fermentation and aging process, reducing its content. Making your own yogurt or kefir allows you to control the fermentation time, which in turn controls the amount of lactose removed. The cultures in these products continue to digest lactose even after consumption, further aiding digestion.

Comparison of Lactose Removal Methods

Feature	Commercial Method (Enzymatic)	Commercial Method (Filtration + Enzyme)	DIY Method (Enzyme Drops)	DIY Method (Fermentation)
Cost	Relatively low, but higher than standard milk.	Higher due to complex equipment.	Very affordable; cost of drops is minimal.	Low cost; requires a starter culture.
Convenience	Grab-and-go from the store.	Grab-and-go from the store.	Requires 24+ hours of preparation.	Requires active maintenance of cultures and process.
Taste	Noticeably sweeter.	Neutral, like regular milk.	Noticeably sweeter.	Tangier and more acidic flavor.
Control	Standardized, consistent product.	Standardized, consistent product.	Adjustable based on enzyme quantity and time.	Variable based on fermentation time, culture activity.

Naturally Low-Lactose Dairy Products

Some dairy products are naturally low in lactose, making them tolerable for many with mild lactose intolerance. During the aging process, bacteria and enzymes break down lactose. Hard cheeses and fermented products are prime examples.

Hard Cheeses

Due to the aging process, hard cheeses like cheddar, parmesan, and swiss contain very little to no lactose. The whey, which contains most of the lactose, is drained away early in the cheese-making process. The remaining trace lactose is then consumed by bacteria during ripening.

Fermented Dairy

Properly fermented yogurts, kefir, and buttermilk contain live active cultures that have already digested a significant amount of the lactose. These products can be a good option for those seeking a tasty, probiotic-rich food that is also easier to digest than regular milk.

Important Considerations

While removing lactose can be a great solution, it is important to remember that this process does not remove milk proteins. Those with a true milk protein allergy must avoid all dairy products entirely. Additionally, the enzymatic hydrolysis method increases the final product's sweetness, which may affect its use in certain recipes or appeal to some consumers. For commercial processing, manufacturers have developed sophisticated techniques to manage flavor profiles by combining filtration with enzymatic treatment.

Conclusion

Whether through sophisticated industrial filtration, controlled enzymatic hydrolysis, or simple at-home methods, there are multiple effective ways to remove lactose from dairy products. For those with lactose intolerance, these options provide an opportunity to continue enjoying the nutritional benefits of dairy without the discomfort. Individuals can choose the method that best suits their needs, preferences, and tolerance levels, ensuring that dairy remains a part of their diet. As consumer demand for lactose-free products grows, innovative processing techniques continue to make these options more accessible and refined.

For more information on lactose intolerance and dairy products, consult this resource:

• Lactose Intolerance - StatPearls - NCBI Bookshelf

Frequently Asked Questions

How do lactase enzyme drops work to remove lactose?

Lactase enzyme drops contain the enzyme lactase, which mimics the body's digestive process by breaking down the complex lactose sugar into its simpler, more digestible components, glucose and galactose.

Does lactose-free milk taste different from regular milk?

Yes, milk treated with lactase often has a slightly sweeter taste. This is because glucose and galactose are sweeter than lactose. Filtration methods used commercially can produce a more neutral flavor.

How long does it take for lactase drops to make milk lactose-free?

The process generally requires at least 24 hours in the refrigerator for the lactase enzyme to effectively hydrolyze the lactose. The longer it's left, the sweeter the milk may become.

Can I use lactase drops for cheese and other dairy products?

Lactase drops are most effective for liquids like milk. For products like yogurt or kefir, fermentation by live cultures is the method that reduces lactose. For hard cheese, the aging process naturally reduces lactose content.

Are all fermented dairy products lactose-free?

No, while fermentation reduces lactose, some may still remain. The amount depends on the product and how long it has been fermented. For example, hard cheeses and some yogurts have very little, but others might still contain enough to cause issues for very sensitive individuals.

What is the difference between lactose-free and dairy-free?

Lactose-free products are made from cow's milk but have the lactose removed. Dairy-free products are made from non-dairy sources, such as soy, almond, or oat milk, and contain no dairy components at all.

Is making my own lactose-free milk at home safe?

Using commercial lactase drops as directed is generally considered safe. However, ensure proper food hygiene and refrigeration throughout the 24-hour process to prevent microbial growth.