Key takeaways
- Cell-based milk uses mammary cells to make complete milk: proteins, fat and lactose together.
- Precision fermentation programs microbes such as yeast to make one milk protein at a time, usually whey.
- Precision-fermented whey is already in some foods. Cell-based milk is not yet sold to consumers.
- Both contain real milk proteins, so neither is safe for people with a milk protein allergy.
Walk down the dairy aisle and you might spot ice cream or cream cheese labeled “animal-free dairy.” It’s easy to assume that’s cell-based milk. Usually, it isn’t. Most of those products use a different technology called precision fermentation.
The two approaches share a goal, real dairy without dairy cows, but they get there in very different ways.
At a glance
| Cell-based milk | Precision fermentation | |
|---|---|---|
| What does the work | Mammary cells from a cow (or human) | Microbes such as yeast, fungi or bacteria |
| What it makes | Whole milk: proteins, fat, lactose | Usually one ingredient, such as whey protein |
| Genetic engineering | Not necessarily | Yes, the microbe is given milk-protein genes |
| Contains lactose | Likely, if it replicates whole milk | Typically no |
| In stores today | No | Yes, in some products |
| Closest analogy | An udder in a tank | Brewing, like making beer or insulin |
How precision fermentation works
The Good Food Institute describes precision fermentation as using microorganisms as tiny production factories for specific ingredients. It’s the same technique used for decades to make insulin and the rennet used in most cheese.
For dairy, scientists insert the genetic instructions for a milk protein, such as beta-lactoglobulin (the main whey protein), into a microbe. The microbe is then grown in fermentation tanks, where it produces the protein. Afterward, the protein is separated out and purified.
The result is one ingredient. To make something that tastes like ice cream or cream cheese, companies combine that protein with fats (usually plant fats), sugars and other ingredients.
How cell-based milk works
Cell-based milk skips the microbe. It takes mammary epithelial cells, the cells that make milk inside an animal, and grows them in a bioreactor. When given the right signals, the cells secrete milk with its proteins, fat globules and lactose produced together, as they would in an udder.
Our step-by-step guide covers the process in detail.
Why the difference matters
Completeness. Milk contains dozens of proteins, plus a complex fat structure that affects how it tastes, foams and turns into cheese. Precision fermentation reproduces the pieces individually. Cell-based milk aims to reproduce the whole thing at once. That’s a big part of the appeal for cheesemakers.
Maturity. Precision fermentation is further along. It relies on fermentation infrastructure that already exists worldwide, and its products have cleared regulatory review. In May 2025, for example, TurtleTree received an FDA “no questions” letter for its precision-fermented lactoferrin, LF+.
Cost and scale. Microbes grow fast and are cheap to feed. Mammalian cells grow slowly and need expensive growth media. That’s why cell-based milk remains at the pilot stage while precision-fermented whey is already sold.
Labeling and perception. Precision fermentation involves genetically engineered microbes, although the final purified protein typically contains no microbial DNA. Cell-based milk may not require genetic engineering at all, which some companies see as a marketing advantage.
A company that switched lanes
TurtleTree is a useful case study. The Singapore-founded startup began as one of the best-known cell-based milk companies, then made a precision-fermented protein its first commercial product. Read the full story in our TurtleTree profile.
What about allergies and lactose?
Both technologies produce real milk proteins. If you have a milk allergy, assume neither is safe for you; read labels carefully, as “animal-free” products typically carry allergen warnings.
Lactose is a different story. Precision-fermented products usually don’t contain lactose, because the microbe only makes protein. Cell-based milk that replicates whole milk is expected to contain lactose, since mammary cells make it naturally. See lactose intolerance and milk allergy for details.
The bottom line
If you’ve eaten “animal-free” dairy, you’ve most likely tried precision fermentation. Cell-based milk is the more ambitious bet, aiming to make the entire glass of milk rather than its parts, but it’s still a few years from your local store.
Sources
- Good Food Institute, Fermentation: An introduction
- Vegconomist, TurtleTree becomes first to receive FDA clearance for precision-fermented lactoferrin, May 2025
- Investigate Midwest, UnReal Milk: will it do a body good?, March 2025
