What yogurt does not have live cultures and how to tell

December 27, 2025 •

4 min read

Despite common belief, not all yogurt contains live and active cultures; some varieties undergo a heat-treatment process after fermentation that kills the beneficial bacteria. This post-fermentation pasteurization is often used to extend shelf life, resulting in a product that lacks probiotic benefits.

Quick Summary

Many yogurts, particularly shelf-stable and frozen types, are heat-treated after culturing, a process that eliminates live and active probiotic bacteria. It is essential to check product labels for terms like 'heat-treated' or the 'Live & Active Cultures' seal to confirm probiotic content.

Key Points

Heat Treatment Kills Cultures: The primary reason some yogurt lacks live cultures is a pasteurization step that occurs after fermentation to prolong shelf life.
Frozen Yogurt May Lack Cultures: While often starting with live cultures, the freezing process reduces their viability, and some products are heat-treated, eliminating them completely.
Check Labels for the LAC Seal: The 'Live & Active Cultures' (LAC) seal is the clearest indication that a product contains viable, beneficial bacteria.
Read the Ingredients List: The ingredient list will either name the specific bacterial cultures or might include a statement like 'heat treated after culturing,' which confirms the cultures are inactive.
Refrigeration vs. Shelf-Stable: Unrefrigerated or shelf-stable products are almost certainly heat-treated and do not contain live cultures, while refrigerated yogurts are more likely to.
Dormant vs. Dead: Freezing makes cultures dormant but doesn't always kill them, whereas heat treatment explicitly kills them.
Inactive Cultures May Still Offer Benefits: Even after being killed by heat, the cellular components and byproducts of the bacteria can offer some nutritional benefits, though not the probiotic effect.

The Heat Treatment Process: The Key Factor

Yogurt is traditionally made by fermenting milk with beneficial bacteria, primarily Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus. These live cultures consume lactose and produce lactic acid, which gives yogurt its characteristic tangy flavor and thick texture. However, some manufacturers add a critical step to this process that fundamentally changes the end product.

While the milk is always pasteurized before the cultures are added to kill unwanted microbes, some yogurts are pasteurized again after the fermentation is complete. This second heat treatment kills the live bacteria, preventing further fermentation and stopping the yogurt from becoming more sour over time. This process is commonly applied to products that are shelf-stable or require a very long shelf life. As the search results indicate, heating yogurt above 130°F (54°C) will kill the majority of these heat-sensitive cultures.

Products Commonly Without Live Cultures

Heat-Treated (Pasteurized) Yogurt

Some dessert-style yogurts and drinkable yogurt products are designed for extended shelf life and are not kept in the refrigerated section. These products are a prime example of heat-treated yogurt. Because the cultures are killed, they do not offer the probiotic benefits associated with live yogurt. Their consistency and flavor are often milder and more consistent than live culture yogurts, which can continue to develop a tangy taste during storage. This heat treatment is especially prevalent in international markets and for products designed for wide distribution.

Frozen Yogurt

For consumers seeking probiotic benefits, frozen yogurt can be a tricky product. While it is made with a base of live cultures, the freezing process can make them dormant, and some products have a significantly reduced number of viable cultures compared to refrigerated yogurt. Furthermore, some manufacturers may heat-treat the product after freezing, killing the cultures entirely. The National Yogurt Association (NYA) has a voluntary certification for frozen yogurt, but the required minimum number of cultures per gram is lower than for refrigerated products. As with other products, careful label reading is key.

How to Spot Yogurt Without Live Cultures

To ensure you are purchasing a yogurt with live and active cultures, follow these steps:

Look for the 'Live & Active Cultures (LAC)' Seal: This seal from the National Yogurt Association (NYA) is a voluntary certification that indicates the yogurt contained at least 100 million live and active cultures per gram at the time of manufacture. If a yogurt has this seal, it contains live cultures.
Read the Ingredients List: The ingredient list on the back of the container will often explicitly state the cultures used, such as Lactobacillus bulgaricus and Streptococcus thermophilus. Be wary if you do not see these listed. Also, look for any phrases indicating post-fermentation heat treatment, such as “heat treated after culturing”.
Check the Refrigeration: Products sold on a shelf at room temperature, particularly desserts, will not have live cultures. For frozen products, check the label, as freezing puts cultures into a dormant state, and some products are completely heat-treated.

Comparison of Yogurts: Live vs. Inactive Cultures


Feature	Live Culture Yogurt	Heat-Treated Yogurt
Presence of Probiotics	Yes, contains beneficial, live bacteria.	No, the bacteria have been killed during processing.
Shelf Life	Shorter, requires refrigeration, and cultures continue to ferment slowly.	Longer, can be sold at room temperature, no further fermentation.
Flavor Profile	Tangy due to lactic acid production by live bacteria.	Milder and sweeter, as fermentation is halted.
Health Benefits	Probiotic benefits for gut health and digestion.	Lacks probiotic benefits; retains nutritional value of milk (protein, calcium).
Primary Use	Regular food, health-focused dietary component.	Dessert items, snacks, or cooking ingredients.

Conclusion

Understanding which yogurt does not have live cultures is crucial for anyone seeking the probiotic benefits of fermented dairy. The key distinction lies in whether the yogurt undergoes a second heat treatment after fermentation. This process, often used to extend shelf life for shelf-stable or frozen products, effectively kills the live and active cultures. To be certain your yogurt contains probiotics, check for the 'Live & Active Cultures' seal from the National Yogurt Association or review the ingredient list for specific bacterial names. Without live cultures, the product is essentially a milk-based food with protein and calcium, but without the functional probiotic benefits. For more information on the processing of dairy products, you can explore resources like this article from the National Institutes of Health: https://pmc.ncbi.nlm.nih.gov/articles/PMC5302305/.

What yogurt does not have live cultures?

Heat-treated yogurt: Products that are pasteurized after fermentation to extend their shelf life.
Frozen yogurt: Often contains dormant or reduced levels of live cultures, and some are heat-treated entirely.
Shelf-stable desserts: Unrefrigerated, yogurt-like products that are processed for long shelf life.
Flavored drinks: Some manufacturers use heat treatment to ensure a consistent, non-tangy flavor in drinkable products.
Ingredients list: If the label does not explicitly mention live cultures, it may not contain them.

How to tell if yogurt has live cultures?

Check for the LAC seal: Look for the National Yogurt Association's 'Live & Active Cultures' seal.
Read the label: Look for terms like 'heat treated after culturing,' which indicates no live cultures.
Look for bacterial names: Confirm that the ingredients list includes names like Lactobacillus bulgaricus and Streptococcus thermophilus.
Assess the tang: Live cultures produce lactic acid, resulting in a tangy taste, while heat-treated yogurt is often sweeter and milder.
Consider the source: Refrigerated yogurt is more likely to have live cultures than unrefrigerated dessert or long-shelf-life products.

Frequently Asked Questions

This phrase on a label means the yogurt was heated to a high temperature after the fermentation process was complete. This second pasteurization step kills all the live bacterial cultures, eliminating their probiotic benefits.

No. While frozen yogurt starts with live cultures, the freezing process can reduce their number or put them into a dormant state. Some brands also heat-treat their products to extend shelf life, so it is essential to check the label for the 'Live & Active Cultures' seal.

Killing the cultures extends the product's shelf life and prevents the yogurt from becoming more acidic or tangy over time. This is useful for manufacturers producing long-lasting, dessert-style, or room-temperature products.

Yes, even without active probiotics, heat-treated yogurt still provides the nutritional value of milk, such as protein, calcium, and vitamins. However, it lacks the specific gut health benefits associated with live bacterial cultures.

The most reliable way is to look for the 'Live & Active Cultures (LAC)' seal on the packaging. You can also check the ingredient list for the specific names of the live cultures used, like Lactobacillus bulgaricus and Streptococcus thermophilus.

Traditional Greek yogurt is made with live cultures and is subsequently strained to remove whey, making it thicker and higher in protein. However, 'Greek-style' products may contain thickening agents and could be heat-treated, so it's always best to check the label for the LAC seal.

Active cultures are living bacteria that provide probiotic benefits to the gut. Inactive (or heat-killed) cultures are no longer alive and do not offer the same probiotic effects, though the product may still contain some nutritional value.