Is citric acid from animals? The truth about its surprising origin

November 25, 2025 •

3 min read

Globally, more than two million tons of manufactured citric acid are produced annually, with the vast majority not derived from animals. Instead, commercial manufacturing relies on microbial fermentation, a process far removed from animal sources, addressing the question of is citric acid from animals for health-conscious consumers and vegans.

Quick Summary

This article clarifies the origin of commercial citric acid, explaining that modern production relies on microbial fermentation using fungi, not animal products. It details the process, distinguishes it from natural citric acid, and confirms its vegan status.

Key Points

Natural Origin: Citric acid exists in trace amounts within all aerobic organisms, including animals and plants, as a metabolic intermediate in the Krebs cycle.
Commercial Production: The vast majority of commercially produced citric acid is not derived from animals but is made through microbial fermentation.
Microbial Source: The primary microorganism used for industrial fermentation is the black mold Aspergillus niger, which converts plant-based sugars into citric acid.
Vegan Friendly: Since its commercial production relies on plant sugars and fungi, manufactured citric acid is widely considered vegan.
No Animal Products: The industrial process is far more efficient and cost-effective than extraction from fruits and does not require animal-derived materials.
Purification Process: Advanced purification methods ensure that mold residues are removed from the final citric acid product, making it safe for consumption.
Widespread Use: This manufactured form is a common additive in foods, beverages, cosmetics, and cleaning products due to its preservative and acidic properties.

Unveiling the Source: Is Citric Acid From Animals?

For many, the name 'citric acid' immediately brings to mind citrus fruits like lemons and limes, leading to the assumption of a plant-based origin. However, a growing number of consumers—particularly those following a vegan or plant-based diet—are asking a more direct question: is citric acid from animals? While citric acid is a ubiquitous organic compound found in trace amounts across the biological world, including plants and animals, the answer for commercially used citric acid is quite different. The reality is that the citric acid found in most processed foods, beverages, cosmetics, and cleaning products today is produced industrially through a highly efficient microbial fermentation process that does not involve animals.

Natural Presence in the Animal Kingdom

Citric acid is naturally present in small quantities in animals as it is a crucial intermediate in the citric acid cycle (Krebs cycle), a fundamental metabolic process occurring in the mitochondria of most aerobic organisms. This cycle is essential for energy production in cells. While it is found in animal tissues and fluids, the amounts are too small for commercial extraction.

The Age of Industrial Fermentation

The modern industrial production of citric acid relies on microbial fermentation rather than extraction from either fruits or animals. This method became dominant after American food chemist James Currie discovered in 1917 that the mold Aspergillus niger could efficiently produce citric acid from sugar. This offered a more economical and scalable alternative to fruit extraction.

The Fermentation Process Explained

The industrial production of citric acid using Aspergillus niger involves several key steps:

Substrate Preparation: Carbohydrate sources like corn steep liquor or molasses are prepared.
Fermentation: Aspergillus niger is grown in large bioreactors, consuming sugars and producing citric acid.
Filtration: The fungal biomass is filtered from the liquid containing citric acid.
Purification: Various steps, including precipitation with calcium hydroxide and treatment with sulfuric acid, purify the citric acid.
Crystallization and Drying: The purified citric acid is crystallized and dried into a powder.

Comparison: Natural vs. Commercial Citric Acid

This table highlights the differences between naturally occurring and commercially produced citric acid.


Feature	Naturally Occurring Citric Acid	Commercial Citric Acid
Source	Trace amounts in plants and animals	Microbial fermentation using Aspergillus niger
Method of Production	Metabolic byproduct of Krebs cycle	Industrial fermentation of plant-based sugars
Scale	Very small	Large-scale, efficient
Vegan Status	Present within the organism	Generally considered vegan
Applications	Biological metabolism	Food additive, pharmaceuticals, etc.

Is All Citric Acid Vegan?

Because commercial citric acid is produced through fermentation of plant sugars by a fungus, it is widely considered vegan. While some very strict vegans might consider concerns about processing aids, certified vegan options are available for assurance. For more information on vegan standards, you can refer to organizations like the Vegan Society.

Beyond Citric and Fermentation

Citric acid is found naturally in various fruits and vegetables, including:

Lemons and limes
Pineapples
Berries
Tomatoes
Cherries
Broccoli and carrots

Conclusion

In summary, while citric acid is present in animals in tiny amounts as part of metabolism, the citric acid used commercially is produced through the microbial fermentation of plant-based materials using the fungus Aspergillus niger. This efficient industrial process does not rely on animal sources, making commercially produced citric acid generally vegan-friendly.

For a more detailed explanation of how citric acid is produced and its role in biochemistry, consult resources such as the American Chemical Society.

Frequently Asked Questions

Commercial citric acid is generally considered vegan as it's made by fermenting plant-based carbohydrates with a fungus, not from animal sources. Certified vegan options are also available for those with stricter requirements.

Yes, animals produce small amounts of citric acid as a normal part of their metabolism in the Krebs cycle. However, this is not the source for industrial-scale production.

The main source is microbial fermentation using the black mold Aspergillus niger grown on a substrate of plant-based sugars like corn steep liquor, molasses, or starch.

Extracting citric acid directly from citrus fruits is too expensive and inefficient for the high global demand. The fermentation process offers a more scalable and economical solution.

Modern purification processes are highly effective and are designed to remove mold residues from the final citric acid product. The finished product is generally considered safe and poses no health risk from mold.

Chemically, the citric acid molecule is identical whether naturally occurring or manufactured. The difference lies in the source and the method of production.

The core fermentation process uses plant-based sugars. While concerns about minor processing aids exist for some, modern production is largely free of animal-derived components, and vegan certifications can confirm this.