How Cultivated Meat Is Made
What it is
Cultivated meat production is a biological manufacturing process that replicates, outside the body, the natural mechanisms by which animal muscle tissue grows and repairs itself. Every animal's muscles contain populations of dormant stem cells — called satellite cells or skeletal muscle stem cells — whose biological purpose is to respond to injury or growth signals by proliferating and differentiating into new muscle fibers. Cultivated meat hijacks this natural system. The cells are removed from the animal, given an environment that mimics the inside of a living body, and guided through proliferation and differentiation into muscle tissue that can be harvested, processed, and eaten.
The process has five core stages: biopsy, isolation, proliferation, differentiation, and maturation. Each presents distinct technical challenges that define the current state of the industry.
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Stage 1: The Biopsy
The process begins with the living animal. A small tissue sample — typically a few grams — is extracted from a muscle via a needle biopsy or minor surgical procedure. The procedure is minimally invasive and is performed under local anesthesia. The donor animal is not harmed in any lasting way and survives to live a normal life. A single biopsy from a single cow, properly managed, can in theory yield enough satellite cells to generate an enormous quantity of meat — estimates vary widely, but some researchers have suggested that one biopsy could theoretically produce hundreds of thousands of pounds of product over time, given sufficient cell line stability.
This is one of cultivated meat's most philosophically striking features: the near-complete decoupling of the living animal from the production process. The animal is a cell donor, not a production input. Whether this constitutes a meaningful ethical improvement over conventional slaughter depends on one's ethical framework — a question addressed in the ethical dimensions section below.
The choice of donor animal matters. Different species have satellite cells with different proliferation rates, different sensitivity to growth factors, and different tendencies to differentiate on command. Chicken satellite cells have proven particularly tractable, which is one reason chicken has been the most commercially successful cultivated meat product to reach market so far. Beef is more challenging. Fish (particularly salmon) presents a different set of biological variables and has attracted specialized companies like Wildtype.
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Stage 2: Isolation of Satellite Cells
Once the biopsy tissue is collected, it is enzymatically digested to break down the extracellular matrix — the connective tissue scaffolding that holds muscle tissue together in the body — and release the individual cells. The resulting cell suspension is then sorted to isolate the satellite cells from other cell types present in muscle tissue (fibroblasts, endothelial cells, fat precursor cells, and others). This isolation is typically done using fluorescence-activated cell sorting (FACS) or magnetic-bead cell sorting (MACS), which use antibodies tagged to fluorescent markers or magnetic particles that bind specifically to surface proteins expressed by satellite cells.
The isolated satellite cells are the founding population of the entire production run. Their quality — their proliferative capacity, their genetic stability, their differentiation potential — determines everything downstream. A key challenge in cultivated meat research is maintaining cell lines that retain their potency across many generations of division. Normal satellite cells have a finite replicative lifespan (the Hayflick limit), after which they senesce and stop dividing. Overcoming this without introducing genetic modifications that might alter the product's regulatory status or consumer acceptability is one of the central technical problems in the field.
Some companies work with immortalized cell lines — cells that have been modified to divide indefinitely — while others seek to maintain primary (unmodified) cells by optimizing culture conditions. The immortalized cell line approach raises its own questions: whether modified cells produce a product that is genuinely equivalent to conventional meat, and whether consumers and regulators will accept it.
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Stage 3: Proliferation — The Growth Medium Problem
Isolated satellite cells must be fed and maintained in a liquid growth medium that supplies everything a living body would normally provide: amino acids, sugars, lipids, vitamins, minerals, and crucially, growth factors — signaling proteins that tell cells to divide. In the body, these signals come from surrounding tissues, hormones, and the bloodstream. In a bioreactor, they must be supplied externally.
For most of the field's history, the standard growth medium for mammalian cell culture has been a formulation based on fetal bovine serum (FBS): blood serum extracted from fetal calves, typically obtained by cardiac puncture of fetuses removed from pregnant cows slaughtered at meatpacking facilities. FBS is extraordinarily effective as a cell culture medium because it contains a complex cocktail of growth factors, hormones, and proteins — essentially a biochemical summary of everything a mammalian fetus needs to grow. It is also, in the context of cultivated meat, a profound irony: a technology premised on reducing animal slaughter has historically depended on a product that requires slaughter (of pregnant cows) and is produced with significant animal welfare concerns.
This contradiction has been the industry's most prominent technical and ethical tension. FBS is expensive (typically $400–800 per liter), is subject to significant batch-to-batch variability, carries biosafety concerns (potential contamination with bovine viruses), and its production process is antithetical to the animal welfare rationale for cultivated meat. The search for serum-free growth media — formulations that supply the necessary growth factors through recombinant proteins (produced by genetically engineered microorganisms) rather than animal-derived serum — has been one of the central research priorities in the field since at least 2015.
Progress has been substantial but not fully resolved. Several companies have announced the development of proprietary serum-free or reduced-serum media. Academic groups have published peer-reviewed formulations. Recombinant growth factors, particularly FGF2 (fibroblast growth factor 2) and IGF-1 (insulin-like growth factor 1), have been produced at increasingly competitive costs through microbial fermentation. The goal — a defined, animal-free, cost-competitive growth medium — appears achievable. As of the early 2020s, serum-free production has been demonstrated at lab scale; scaling it economically remains a challenge.
The growth factors themselves are expensive. A key cost driver in cultivated meat economics is the price of recombinant growth factors at production volumes. Research into "growth factor-free" approaches — engineering cell lines that produce their own growth factors autocrinally, or using small-molecule alternatives to protein growth factors — represents a frontier of the field.
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Stage 4: Differentiation
After sufficient proliferation — when the cell population has expanded from thousands to billions — the cells must be induced to differentiate: to stop dividing and begin the process of becoming mature muscle fibers. In the body, satellite cells differentiate in response to injury signals, mechanical tension, and the withdrawal of certain growth factors. In the bioreactor, differentiation is typically induced by switching the cells to a low-serum or serum-free "differentiation medium" that contains different signaling molecules — particularly IGF-1, transferrin, and sometimes insulin.
During differentiation, individual muscle cells (myoblasts) fuse with each other to form multinucleated muscle fibers (myotubes), the same process that occurs during fetal muscle development and wound healing. These myotubes then mature into muscle fibers, upregulating the expression of contractile proteins (actin, myosin) that give muscle its characteristic texture.
This stage is where cultivated meat's texture challenges become most apparent. A thin sheet of muscle cells on a flat surface will produce a product resembling ground meat or a meat paste — suitable for burgers, nuggets, sausages, and other reformed products. Creating the fibrous, layered, three-dimensional structure of a whole-muscle cut — a steak, a chicken breast, a fish fillet — requires solving the scaffolding problem.
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Stage 5: Scaffolding and Three-Dimensional Structure
Conventional meat has a complex three-dimensional architecture. Muscle fibers are bundled into fascicles, surrounded by connective tissue (endomysium, perimysium, epimysium), interspersed with fat cells (intramuscular fat, or marbling), threaded with blood vessels (which in the living animal supply oxygen and nutrients to cells deep in the tissue), and organized in specific geometric orientations that give different cuts their characteristic texture, grain, and behavior when cooked.
Growing a thin layer of cells on a flat surface produces none of this architecture. The cells at the surface of a thick slab would be nourished by the medium; the cells in the interior would be starved of oxygen and nutrients, dying and creating a necrotic core. This is the scaffolding problem: how to create a three-dimensional support structure that allows cells to grow in the correct orientation, receive nutrients throughout the depth of the tissue, and ultimately produce a product with the texture, appearance, and cooking behavior of a whole-muscle cut.
Multiple approaches are being pursued:
Edible scaffolds: Biopolymer matrices made from food-grade materials — mycelium (fungal fibers), soy protein, cellulose derivatives, pea protein, or chitosan (from crustacean shells) — can be fabricated into porous structures that mimic the extracellular matrix. Cells seeded onto these scaffolds can grow into three-dimensional structures. If the scaffold material is itself edible and culinarily neutral, it can remain in the final product.
Decellularized plant scaffolds: Plants have vascular systems that can be chemically stripped of their cellular material, leaving behind the plant's fibrous scaffolding with intact micro-channels that served as the plant's vascular system. These channels can then serve as a rudimentary vascular network for perfusing nutrients through a tissue construct. Spinach leaves have been a widely cited example; their vascular architecture, after decellularization, has been seeded with mammalian cells in laboratory demonstrations.
3D bioprinting: Cells can be mixed with bioink — a printable hydrogel — and deposited in precise three-dimensional patterns using modified 3D printers. This allows construction of complex tissue architectures, including layered fat and muscle, with a precision not achievable by other methods. The challenge is scaling bioprinting from laboratory demonstrations to commercial production volumes.
Perfusion bioreactors: Bioreactor designs that pump nutrient medium through the scaffold structure — mimicking the function of blood vessels — can support thicker tissue constructs. The most sophisticated cultivated meat bioreactors incorporate such perfusion systems.
The scaffolding challenge is widely recognized as the primary technical barrier separating cultivated meat's current commercial reality (ground-meat equivalents, nuggets, sausages, blended products) from its long-term aspiration (whole muscle cuts, steaks, fish fillets with intact structure). As of the mid-2020s, whole-muscle cultivated cuts have been produced as laboratory demonstrations but have not reached commercial production.
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Stage 6: The Bioreactor
The bioreactor is the production vessel — the industrial analog of the animal's body. For proliferation, large stirred-tank bioreactors (similar to those used in pharmaceutical fermentation) maintain cells in suspension at controlled temperature (typically 37°C for mammalian cells), pH, dissolved oxygen concentration, and agitation. Cells in suspension culture can be grown to very high densities. For differentiation and maturation, different bioreactor configurations — including perfusion systems, hollow-fiber bioreactors, and wave bioreactors — may be used depending on the product format.
The bioreactor's environmental control systems must maintain precise conditions: temperature within tenths of a degree, pH between 7.2 and 7.4, dissolved oxygen above critical thresholds, and sterility (contaminating microorganisms would quickly outcompete and overwhelm the slower-dividing mammalian cells). These requirements make cultivated meat production facilities significantly more complex than conventional food manufacturing.
Bioreactor scaling is a major challenge. Pharmaceutical bioreactors at the 20,000-liter scale have been operated for decades, but pharmaceutical products are proteins produced in tiny quantities per liter; cultivated meat requires producing bulk tissue at food commodity prices. The engineering challenges of scaling cell culture from laboratory flasks to industrial bioreactors while maintaining product quality, sterility, and cell viability are substantial.
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The Cost Trajectory
The history of cultivated meat cost reduction is one of the most dramatic in food technology. When Mark Post's team at Maastricht University produced the first cultivated beef burger for a public tasting in August 2013, the product cost approximately $330,000 to produce — a figure that became the defining image of the technology's early stage. By 2023, companies were reporting production costs in the range of $10–20 per pound for chicken products, with aspirations of reaching price parity with conventional meat at scale. Some industry analysts project that parity could be achieved in the $2–5 per pound range within a decade, though these projections carry significant uncertainty.
The cost reduction has come from multiple sources: more efficient growth media formulations, improved cell line performance, better bioreactor designs, and economies of scale. The growth factor cost problem — recombinant FGF2 in pharmaceutical-grade quantities costs hundreds of dollars per milligram — is being addressed by producing these proteins through microbial fermentation at food-grade rather than pharmaceutical-grade standards. Feed conversion ratios (the amount of input resources required per unit of output) for cultivated meat are still being calculated and debated; early life-cycle analyses have shown a complex picture where the environmental benefits depend critically on the energy source used to power the bioreactors and the composition of the growth medium.
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