Venture-backed lab-grown meat companies—including Memphis Meats, Mosa Meat, Just Inc., and Finless Foods—have spent hundreds of millions of dollars learning to cultivate cow, chicken, pig, and fish cells in specialized vats known as bioreactors. The hope is that one day, they’ll be able to grow animal cells at a large enough scale to provide a competitively priced, less resource-intensive alternative to traditional stockyards, factory farms, and fisheries. Although many questions remain unanswered—including what exactly to call these foods— it’s almost certain that if and when the first generation of motherless meats arrive in grocery stores, they will not be steaks, chops, or filets. They will be meatballs, sausages, and extruded nuggets—processed foods that combine laboratory-raised cells with plant proteins, grains, and other ingredients.
This is because cultured meat research has, up until this point, operated largely in the realm of the two-dimensional—growing animal cells, rather than simulating entire animal tissues. When we eat meat, what we’re really doing is consuming muscle tissue, an organized community of cells that includes not only skeletal muscle cells, but also fat cells, collagen, nerves, blood, and blood vessels. This supporting structure of sinew and vasculature is what produces the full sensory experience of meat, and is the difference between a muscle-cell slurry and a steak.
But growing three-dimensional meat is a challenge. Typically, animal cells must be within 200 microns from a nutrient supply in order to survive; that’s about the width of a human hair. This is known as the diffusion limit, and it’s why you see cells growing along only the surface of a petri dish, rather than in heaps and piles. In living animal bodies, an extracellular matrix of collagen supports the development growth of complex muscle tissues.
