Lactic acid

A mildly sour organic acid made by fermenting sugars; used to acidify, preserve, and enhance flavor in foods.

Should I eat Lactic acid?

This is a refined, fermentation‑derived acid that safely lowers pH to help keep foods safer. Avoid it for infants and be cautious if you have short bowel syndrome; it is not a probiotic and simply adds acidity.

Summary

Lactic acid is a mildly sour organic acid made by fermenting plant sugars and then purifying the result. In foods, its main job is to control pH, which shapes taste and slows unwanted microbes. Safety reviews by authorities support low toxicity at typical use levels, though U.S. rules do not allow it in infant foods or formulas. People with short bowel syndrome are sensitive to D‑lactate and should avoid D‑lactate–rich fermented products. Despite its fermentation origin, the final ingredient is highly refined and contains no live cultures.

Key Research Points

Fermented, then highly purified

Lactic acid starts with fermentation of plant sugars, then goes through neutralization, re‑acidification, and purification. It’s an acidity regulator added for pH control, not a live‑culture ingredient.

Lowers pH to deter germs

By making foods more acidic, lactic acid slows spoilage microbes and can reduce harmful bacteria on surfaces. Meat plants also use defined 2–5% sprays to cut contamination during processing.

Special caution: early life/SBS

U.S. rules do not allow lactic acid in infant foods or formula, and people with short bowel syndrome can build up D‑lactate and develop acidosis. Healthy individuals do not show this issue at typical food intakes.

Overview

What is it?

Source: Plant sugars

Method: Ferment sugars, neutralize, release acid, purify

Processing Level: 8 / 10

Why is it used?

Purpose: Mild organic acid used to acidify foods, control pH, and inhibit microbes.

Commonly found in: Pickles, Yogurt, Sourdough bread, Deli meats, Beverages

Why manufacturers choose it: Dependable, clean‑tasting acidulant that boosts safety and flavor at low cost and low use levels.

Origin

First isolated from sour milk by Carl Wilhelm Scheele in 1780; long used in fermented foods like yogurt, sauerkraut, kimchi, and sourdough. Modern production ferments plant-derived sugars with lactic acid bacteria, followed by purification. Major producers use sugarcane or corn feedstocks and supply food, pharma, and PLA bioplastic markets.

Process: Ferment sugars, neutralize, release acid, purify

Steps

1. Ferment: Lactic acid bacteria ferment plant sugars to lactic acid.

2. Neutralize/pH control: Calcium carbonate or hydroxide added to keep pH stable, forming calcium lactate.

3. Acidolysis: Sulfuric acid converts calcium lactate back to lactic acid, forming gypsum.

4. Clarify & decolorize: Solids removed; activated carbon/ion exchange reduce impurities.

5. Concentrate: Water removed to desired strength; food-grade solution packaged.

Chemicals

Calcium carbonate or calcium hydroxide

Sulfuric acid

Activated carbon

Ion-exchange resins

Research & Safety

Potential Concerns

Regulatory rules in the U.S. prohibit lactic acid in infant foods and formulas; parents should not rely on labels that imply otherwise. People with short bowel syndrome should be cautious with D‑lactate–rich fermented foods or supplements and seek clinical guidance. Like other acids, frequent exposure to acidic drinks can erode tooth enamel over time; minimizing sipping and rinsing with water helps. Concentrated lactic acid solutions (e.g., industrial or DIY) can irritate skin and the gastrointestinal tract if mishandled; foods use much lower levels.

Potential Benefits

No demonstrated nutrimental benefit

Digestive Effects

At normal food levels, lactic acid is well tolerated. Large bolus intakes of strong acids (including concentrated lactic acid solutions) may cause transient stomach irritation or heartburn in sensitive people. Individuals with reflux disease may find acidic foods aggravating symptoms and can moderate intake accordingly. D‑lactic acidosis is a rare, specific complication seen mainly in short bowel syndrome and is not a risk for healthy people consuming typical foods.

Limit Consumption

Infants and especially preterm neonates are a special population; U.S. regulations exclude lactic acid from infant foods/formulas, and historical evaluations caution against D‑ or DL‑lactate in infant products. People with short bowel syndrome should avoid D‑lactate–rich fermented foods or probiotics unless supervised by a clinician. Those with active dental erosion or high cavity risk should limit frequent sipping of acidic beverages and practice enamel‑friendly habits (rinse with water; wait before brushing). Lactic acid is generally compatible with vegan, kosher, halal, gluten‑free, and dairy‑free diets because it is produced by fermenting plant sugars.

Fact Sheet

Regulatory Status

US FDA: GRAS (21 CFR 184.1061) for foods at GMP levels, EXCEPT infant foods/formulas.

EU Status: Approved food additive E270; widely permitted as acidity regulator and processing aid (e.g., carcass rinses).

Codex INS: INS 270

JECFA ADI: ADI ‘not specified’ (consistent with low toxicity at GMP use).

ESG & Sustainability

Environmental Footprint: Impacts depend on feedstock and recovery method; LCAs report ~2–5 kg CO2e per kg lactic acid with hotspots in pretreatment and purification.

Sustainability: Fermentation from renewable sugars; co-product gypsum from acidolysis requires management; improving membrane/solvent-free recovery lowers impacts.

Animal Welfare: No direct animal-welfare concerns; widely used in plant-based foods.

Carbon Footprint: Representative LCA example: ~4.6 kg CO2e/kg lactic acid (sugarcane bagasse route); company LCAs report ranges depending on site and energy mix.