Is Lactic Acid Animal-Based or Plant-Based?

December 7, 2025 •

4 min read

Over 90% of commercially produced lactic acid comes from microbial fermentation of plant-based carbohydrates, not animal sources. This fact challenges the common misconception that lactic acid is always animal-based due to its name and historical association with milk. For those navigating dietary choices, understanding the true origin of lactic acid is key to making informed decisions.

Quick Summary

The origin of lactic acid is often misunderstood; while historically associated with milk, most commercial lactic acid is produced via plant-based fermentation. The substance itself contains no animal compounds, even when derived from dairy sugars, though manufacturers are not required to label the source. Consumers must contact companies to verify the origin for strictly vegan diets.

Key Points

Source Varies: Lactic acid can be derived from either plant-based (cornstarch, beet sugar) or animal-based (lactose/whey) sources through fermentation.
No Animal Compound: The final lactic acid molecule is chemically identical regardless of its origin, and contains no animal compounds.
Labeling Ambiguity: Food labels often don't specify the source of commercially added lactic acid (E270), making verification difficult.
Vegan Verification: For a strictly vegan diet, contacting manufacturers or choosing products with clear vegan certification is the only way to confirm a plant-based origin.
Latin Name Misconception: The name 'lactic acid' stems from its initial discovery in sour milk, not because all of it comes from milk.
Naturally Occurs: Lactic acid is naturally present in both plant-fermented foods (sauerkraut, sourdough) and animal-fermented foods (yogurt).

Understanding the Origins of Lactic Acid

Lactic acid is an organic compound with the chemical formula C₃H₆O₃, and despite its name suggesting a link to milk (from the Latin 'lac'), it is not inherently animal-derived. The substance is produced through the fermentation of carbohydrates by specific types of bacteria. This process, known as lactic acid fermentation, can use a variety of substrates, and the origin of the feedstock ultimately determines if the product is plant or animal-based.

Where Lactic Acid is Found and Produced

Lactic acid occurs naturally in a wide range of fermented foods. This includes both plant-based items, like sauerkraut and sourdough bread, and animal-based products, such as yogurt and cheese. In an industrial context, the compound is primarily used as a preservative, curing agent, and flavor enhancer, designated as E270 in Europe. Most of this commercially produced lactic acid is derived from plant sugars like cornstarch or beet sugar. However, some manufacturing processes may use lactose, a sugar found in dairy, as the fermentation substrate, making the final product non-vegan. The crucial distinction for a vegan is not the presence of lactic acid itself, but the source from which it was produced.

The Fermentation Process: Plant vs. Animal Sources

Lactic acid bacteria (LAB) are the microorganisms responsible for breaking down sugars into lactic acid during fermentation. These bacteria don't have to be of animal origin, and indeed, many are cultured using plant-based media. The substrate choice is the key factor. For example, fermenting cabbage to make kimchi uses the cabbage's natural sugars, resulting in vegan-friendly lactic acid. Conversely, using whey, a dairy by-product, as the starting material creates a non-vegan product. A fascinating aspect is that the final lactic acid molecule is chemically identical regardless of the initial sugar source. Therefore, while the end product contains no animal matter, its ethical and dietary suitability depends on the process.

Common Sources of Lactic Acid

Plant-Based: Fermented vegetables (kimchi, pickles, sauerkraut), sourdough bread, soy products (miso, soy sauce), wine, beer, and many commercially added lactic acids derived from corn or beet sugar.
Animal-Derived: Fermented dairy products (yogurt, kefir, cheese), and fermented meats (salami). The lactic acid present is a natural byproduct of the fermentation of animal-derived substrates.
Industrial (Needs Verification): Added lactic acid in processed foods (dressings, desserts). While most is plant-based, manufacturers are not required by law (in the US) to disclose the source.

Comparison of Lactic Acid Sources


Feature	Plant-Based Lactic Acid	Animal-Based Lactic Acid
Typical Feedstock	Cornstarch, beet sugar, tapioca, vegetable sugars	Lactose (from milk), sugars in fermented meats
Vegan Status	Always vegan, assuming other ingredients are also vegan	Not suitable for vegans due to the animal-derived origin of the substrate
Example Products	Sauerkraut, pickles, some breads, packaged foods with labeled plant source	Yogurt, cheese, kefir, fermented sausage
Labeling Requirements	The source is often not specified on food labels, making verification difficult	The presence of dairy or meat products usually makes the item non-vegan regardless of the lactic acid source
Chemical Purity	Pure lactic acid is chemically identical to lactic acid from any source	No chemical difference in the final compound, but the ethical origin differs

How to Determine the Source

Since food manufacturers are not legally required to specify the source of added lactic acid (E270), relying on ingredient lists can be inconclusive. The only sure way to know if added lactic acid is vegan is to contact the manufacturer directly and inquire about the fermentation feedstock. For products with explicit vegan certification, you can be confident the lactic acid is plant-derived. When in doubt, purchasing products with plant-based certification or avoiding processed foods with unspecified E270 are the safest routes for a strict vegan diet. A good example of this verification process is outlined by the Vegetarian Resource Group.

Conclusion: Navigating Lactic Acid as a Vegan

In conclusion, lactic acid itself is a molecular compound that is not animal-based, but rather a product of bacterial fermentation. The critical factor for those adhering to a vegan diet is the original substrate used to produce the lactic acid. While the majority of industrially added lactic acid comes from plant sources like corn and beets, without clear labeling or certification, ambiguity remains. The Latin root 'lac-' referring to milk is a historical relic from the compound's discovery, not an indicator of its modern-day source. By understanding the production process and verifying with manufacturers, vegans can confidently navigate ingredient labels and avoid unintentionally consuming animal-derived products.

Visit Vegan Friendly's website for more information on vegan ingredient sources.

Frequently Asked Questions

No, E270 is the food additive code for lactic acid, and its source is not specified on the label. While most commercially produced lactic acid is plant-based, some may be fermented using milk sugar, so it cannot be assumed to be vegan.

The name comes from the Latin word for milk, 'lac', because Swedish chemist Carl Wilhelm Scheele first isolated it from sour milk in 1780. The name is a relic of its discovery, not an indicator of its modern production methods.

Lactic acid is naturally found in many plant-fermented foods such as sourdough bread, pickled vegetables, sauerkraut, and kimchi. Industrially, it is often produced by fermenting cornstarch or beet sugar.

The most reliable method is to contact the product's manufacturer and inquire about the source of their lactic acid. Alternatively, look for products that carry an official vegan certification logo.

No, pure lactic acid does not contain lactose, the sugar found in milk. Even if produced using lactose, the fermentation process breaks down the sugar, so the final chemical compound is free of it.

No, lactic acid bacteria (LAB) are microorganisms and are not considered animal-based. However, they can be cultured using either plant-based or animal-based media, such as dairy.

Yes, our own bodies produce lactic acid in muscle tissue during intense exercise. Lactic acid is also naturally present in fermented animal products like yogurt and salami due to the fermentation of animal-derived sugars.