How Greek Yogurt Has Significantly Less Lactose

November 16, 2025 •

3 min read

Over 65% of the world's adult population is estimated to have some degree of lactose malabsorption. While milk and regular yogurt can cause discomfort for these individuals, many find that they can enjoy Greek yogurt without issues. This is because the meticulous process of making Greek yogurt drastically reduces its lactose content, offering a low-lactose alternative that is easier to digest.

Quick Summary

Greek yogurt's lower lactose content is the result of its unique production method, which includes both a fermentation phase and a critical straining process. Live active cultures consume much of the lactose during fermentation, and the straining removes the lactose-rich whey, resulting in a product with a significantly lower lactose concentration than milk or regular yogurt.

Key Points

Lactose Reduction: Greek yogurt has significantly less lactose due to its fermentation and straining process, not because it is entirely lactose-free.
Fermentation Role: Live bacterial cultures break down and consume lactose during fermentation, converting it into more digestible lactic acid.
Straining's Importance: The straining process removes the liquid whey, which is rich in lactose, resulting in a much thicker, higher-protein, and lower-lactose product.
Probiotics Aid Digestion: The live and active cultures in Greek yogurt continue to help digest residual lactose in the small intestine for some individuals.
Lactose-Free Options Exist: For those with severe lactose intolerance, specific lactose-free Greek yogurts are available where all lactose has been removed or broken down.
Mild Intolerance Tolerance: Many people with mild to moderate lactose intolerance can consume Greek yogurt without discomfort due to its lower lactose content.

The Science of Reduced Lactose in Greek Yogurt

Unlike milk, which typically contains around 12 grams of lactose per cup, Greek yogurt undergoes a two-part process that drastically lowers this sugar's concentration. The first is fermentation, where beneficial bacteria get to work. The second, and most significant, is the straining process that defines Greek yogurt's thick texture and low lactose content. It’s important to clarify from the start that standard Greek yogurt is not entirely lactose-free; however, the remaining amount is often well-tolerated by those with mild to moderate lactose intolerance.

Fermentation: The Bacterial Breakdown

The journey to lower lactose begins with the fermentation of milk. Live active bacterial cultures, most commonly Streptococcus thermophilus and Lactobacillus bulgaricus, are added to pasteurized milk. These tiny organisms feed on lactose, the milk sugar, and convert it into lactic acid. This metabolic process is what gives yogurt its characteristic tangy flavor and causes the milk proteins to coagulate, creating a thicker consistency. The longer the fermentation period, the more lactose the bacteria consume, leading to an even lower final lactose level.

Key actions of fermentation:

Bacteria Consume Lactose: Probiotic cultures break down lactose into simpler, more digestible sugars and lactic acid.
Enhances Acidity: The production of lactic acid lowers the yogurt's pH, which helps preserve the product and inhibits the growth of harmful bacteria.

Straining: The Defining Step for Low Lactose

After fermentation, the yogurt is strained multiple times through a cloth or mesh. This step is the most crucial part of creating Greek yogurt and what sets it apart from its regular counterpart. The straining removes the liquid whey, which is a byproduct of cheesemaking and contains a high concentration of lactose. As the whey is removed, the remaining yogurt is a denser, thicker product that is not only richer in protein but also much lower in lactose. The amount of straining determines the final product's thickness and lactose content.

Live and Active Cultures Aid Digestion

Even with a reduced lactose content, standard Greek yogurt isn't entirely devoid of milk sugar. This is where its live and active cultures come in again to help people with lactose intolerance. The bacterial lactase enzyme within the yogurt survives the acidic conditions of the stomach, and continues to aid in the digestion of the remaining lactose in the small intestine. This process essentially helps the body do the work it struggles with, leading to fewer digestive symptoms like bloating or gas.

Factors Influencing Lactose Levels

It is important to remember that not all Greek yogurt is created equal. Several factors can influence the final lactose concentration, so consumers, especially those with severe intolerance, should check the labels carefully. Some producers might add milk powder or other ingredients to thicken their product, which can reintroduce lactose. Others offer truly lactose-free varieties, where lactase enzymes are added during production to break down all the lactose.

Straining Intensity: More straining removes more whey and, consequently, more lactose.
Brand Variations: Different brands may use different production methods, leading to variations in lactose levels.
Added Ingredients: Additives like milk powder can increase lactose content.
Lactose-Free Options: Many manufacturers now offer products labeled explicitly as lactose-free, typically made with lactose-free milk or added lactase enzymes.

How does Greek yogurt have significantly less lactose?


Feature	Greek Yogurt	Regular Yogurt	Milk
Straining	Strained multiple times to remove whey.	Not strained or strained only once.	No straining process.
Lactose Content (6 oz)	~4 grams	~6-8 grams	~12 grams
Protein Content (6 oz)	~16 grams or more	~6-8 grams	~8 grams
Thickness	Thick, creamy, and concentrated.	Thinner consistency.	Liquid.

Conclusion

The perception that Greek yogurt has no lactose is a common misconception, but it is rooted in its significantly lower lactose content compared to other dairy products like milk and regular yogurt. The combination of fermentation, where live cultures consume lactose, and the intensive straining process, which removes lactose-rich whey, results in a final product that is far easier to digest for many people with lactose intolerance. The added bonus of beneficial probiotics continuing to assist with digestion further enhances its digestibility. For those with severe sensitivity, commercially available lactose-free Greek yogurt options provide the creamy texture and nutritional benefits without any concern. The ability for many to enjoy this tangy, high-protein food is a direct result of these precise and effective manufacturing steps.

Visit the US Dairy website to learn more about lactose intolerance and yogurt.

Frequently Asked Questions

No, standard Greek yogurt is not completely lactose-free. It has a significantly reduced lactose content due to the straining and fermentation process, but small amounts of lactose remain.

The live and active bacterial cultures in yogurt contain the enzyme lactase, which helps break down lactose both during fermentation and in your digestive system after consumption.

Greek yogurt is thicker because it has been strained multiple times to remove the liquid whey. This process concentrates the milk solids, resulting in a denser, creamier product.

If you have severe lactose intolerance, standard Greek yogurt may still cause symptoms. However, many brands offer specially produced lactose-free Greek yogurt, which is a safer option.

Yes, a longer fermentation time allows the live cultures more time to consume the lactose, resulting in a finished product with an even lower lactose content.

No, "Greek-style" yogurt may not be strained in the same traditional way and can sometimes use thickeners or milk powders that add back lactose. Always check the label for confirmation.

A 6-ounce serving of Greek yogurt typically contains about 4 grams of lactose, whereas a cup of milk contains around 12 grams. This makes Greek yogurt roughly 65% lower in lactose than milk.