Cell Based Milk
The basics

What is cell-based milk? A plain-English guide

Real milk, made by the same cells that make it inside a cow, without the cow. Here's what that actually means.

Updated 6 min readBy the Cell Based Milk team
Illustration of a glass of milk beside a test tube

Key takeaways

  • Cell-based milk is made by mammary (udder) cells grown in a bioreactor. It's chemically real milk, not a plant-based imitation.
  • It's different from precision fermentation, which uses microbes to make single milk proteins like whey.
  • No cell-based milk is sold in US grocery stores yet. Early companies are targeting pilot launches from 2026 and broader markets around 2028.
  • The environmental benefits are promising but so far rest mostly on company estimates, not independent studies.

Cell-based milk is milk produced by mammary cells grown in a bioreactor rather than inside a cow. The cells are the same kind that line the milk-producing glands of an udder. Given the right nutrients and conditions, they do what they evolved to do: make and release milk.

That’s the whole pitch in one sentence. The rest of this guide covers how it works, how it differs from the other “animal-free dairy” you may have seen, and what’s still standing between the lab and your fridge.

You’ll also hear it called cell-cultured milk, cultivated milk, or simply lab-grown milk. They all mean the same thing.

How cell-based milk works

The process borrows from the same toolkit as cultivated meat, but with an important twist: the goal isn’t to grow lots of cells and eat them. It’s to keep cells alive and productive so they secrete milk.

In broad strokes:

  1. Get the cells. Companies start with mammary epithelial cells, taken from tissue samples or from donated milk, which naturally contains a few live cells. Some companies develop immortalized cell lines that keep dividing indefinitely, so they don’t need to keep going back to animals.
  2. Grow them. The cells are multiplied in a nutrient broth called growth media, inside sterile, temperature-controlled vessels.
  3. Give them structure. Mammary cells like to sit on a surface, with one side facing “blood” (nutrients) and the other facing the “duct” (where milk goes). Many systems use hollow fibers or scaffolds that recreate this arrangement.
  4. Collect the milk. The cells absorb nutrients from one side and release milk components on the other, where they can be collected, often continuously.
  5. Process it. The collected milk is filtered and standardized much like conventional dairy, then drunk as is or made into cheese, butter, or yogurt.

We break each stage down in our step-by-step guide, how cell-based milk is made.

What’s actually in it?

Because the cells are real mammary cells, the goal is to produce the same molecules a cow makes: casein and whey proteins, milk fat, and the milk sugar lactose.

Brown Foods, a Boston startup, said in early 2025 that independent testing at the Whitehead Institute found its UnReal Milk contained the major dairy proteins, including several caseins, beta-lactoglobulin and lactoferrin, along with milk fats and carbohydrates. That’s a company-reported result, but it shows where the technology is aiming: the whole drink, not just one ingredient.

What’s harder to replicate is everything a cow adds from the rest of its body: hormones, antibodies, and the subtle flavor notes that come from what the animal eats. Whether those differences matter for taste and nutrition is one of the big open questions. We dig into it in taste and nutrition.

Cell-based milk vs. “animal-free” whey

This is the most common source of confusion. Some “animal-free dairy” ice creams and cream cheeses already in stores use precision fermentation: microbes like yeast or fungi are given the genetic instructions to make one specific milk protein, usually whey.

Cell-based milk is different in two ways:

  • It uses animal cells, not microbes.
  • It aims to produce complete milk, with fats, sugars and many proteins together, rather than one purified ingredient.

For the full comparison, read cell-based milk vs. precision fermentation.

Why people are excited about it

The short version: if it can be made cheaply at scale, cell-based milk could deliver dairy that tastes and cooks like dairy, with far fewer cows.

Fewer animals. No herds, no calving cycles, no separating calves from their mothers. Ethical concerns about dairy farming are a major motivation for many founders in the field.

A smaller footprint, potentially. Dairy farming is resource-intensive. Per liter, cow’s milk produces roughly three times the greenhouse gas emissions of common plant milks and uses about ten times the land, according to analysis by Our World in Data. Startups claim large savings, but those numbers are early estimates. See our environmental breakdown for the fine print.

Cleaner production. Milk made in a sterile bioreactor shouldn’t need antibiotics, and some producers say it may need less of the downstream processing conventional milk goes through.

Real dairy performance. Plant milks often struggle in cheese and baking because they lack casein. Cell-based milk should behave like the real thing, because chemically it is.

The challenges

Cost. Growth media, the nutrient broth the cells live in, is expensive. Montreal startup Opalia has identified it as the single biggest cost driver it’s working to bring down.

Scale. Growing cells in the lab is one thing; filling grocery shelves is another. Bioreactor capacity for food-grade cell culture barely exists yet.

Regulation and labeling. In the US, the official definition of milk is the secretion “obtained by the complete milking of one or more healthy cows” (21 CFR 131.110). Whether a cell-made product can be called “milk” is an unresolved fight. And in 2026, Mississippi became the first state to ban the manufacture and sale of cell-cultured dairy altogether. More in our guide to safety and regulation.

Consumer trust. People are cautious about new foods, especially ones described as “lab-grown.” Clear labeling and independent testing will matter.

When can you try it?

Not yet, at least not from a store shelf. Brown Foods has said it is aiming for a market pilot in late 2026. Opalia began a paid pilot with Dutch dairy supplier Hoogwegt and is targeting market entry around 2028, starting with regulatory filings in Canada. See when you can buy cell-based milk for the latest timelines, and our company tracker for who’s doing what.

Common questions

Is cell-based milk the same as lab-grown milk?

Yes. Cell-based milk, cell-cultured milk, cultivated milk and lab-grown milk all describe the same idea: milk produced by mammary cells grown outside an animal.

Is cell-based milk real milk?

Biologically, it aims to be. The cells are the same type that make milk in a cow, so the proteins, fats and sugars are the same molecules. Legally it's less clear: US federal rules define milk as coming from the milking of healthy cows.

Can I buy cell-based milk today?

Not in stores. As of late 2026, companies are running tastings and pilots and selling small amounts to dairy businesses for product development. None has completed an FDA review, and Mississippi has banned its sale.

Sources

All articles