In 2013, Dr. Mark Post's team developed the first cultured meat product. It took three lab technicians three months to grow and put together 20,000 cow muscle fibers to make the first $330,000 lab-grown burger . In the coming years, several cellular agriculture ('cell ag') companies are preparing to release their first commercial product . Scaling of the production process will be important to ensure that cell ag is a commercially viable option. There are four key areas that need to be further developed to scale production, and this article will highlight these different parts of production that will make cellular agriculture animal products an alternative to conventional livestock products.
Researchers are looking for a stem cell line from different animals that could become the stable cell line that could (ideally) divide indefinitely into more cells . Stem cells are unique because they have the ability to produce more of itself (the stem cell) via self-replication or to produce cells that become different cell types via differentiation. At the moment, to produce cultured meat, researchers are using cells found in muscle called satellite cells (Yes, these cells are also in us!) . When activated, the satellite cells will either self-replicate to produce more satellite cells or differentiate into muscle fiber cells that can become the meat product. The problem with these cells, however, is that satellite cells have a limited number of self-replications in their lifespans .
Once a stable cell line is found and becomes widely available for animals of interest (like cows, pigs and chickens), sourcing of stem cells to make cultured meat will no longer be an obstacle. In 2017, for example, Memphis Meats co-founder Dr. Nicholas Genovese published a paper highlighting success in producing muscle fibers from induced stem cells from pigs .
The cell culture media, or serum, is the nutritious mixture that cells grow in. The cell culture media provides all of the nutrients and growth factors that cells may need to replicate or differentiate into another cell type . There are two main obstacles in scaling serum: its sourcing and price. In many scientific labs, a common cell culture serum used to grow cells is fetal bovine serum . Not only would this still involve animal sourcing in the production process, fetal bovine serum is "notoriously inconsistent from batch to batch"  as well as very costly. Animal-free serums have been developed for medical purposes, but the problem of costliness remains for scaling production .
The development of an inexpensive and animal-free growth serum for cell lines has once been described as the "Holy Grail"  for cellular agriculture companies. Further innovation and research is required to find a cost-effective solution that would make scaling cell ag production feasible and affordable.
When a building is under construction, it is surrounded by scaffolding for structural support. Similarly, in cellular agriculture, scaffolding provides structural support to cells by outlining the composition and shape of cultured meat . This is important to make sure that the cells grow into muscle fibers that have the same taste, texture, and shape as conventional meat . Scaffolding also promotes the growth of larger muscle fibers needed to scale production .
Further innovation is required to create scaffolding to grow complex meat tissues like steaks . Steaks consist of different amounts of muscle, fat, and connective tissue, and a complex scaffolding to make them will have to be able to replicate their appearance and composition.
Picture taken from “Clean Meat’s Path to Your Dinner Plate” by Emily Byrd for the Good Food Institute
A bioreactor is the chamber that houses the cell culture serum and scaffolding to promote the growth and differentiation of cell lines to cultured meat. Bioreactors are the chamber where all the mentioned aspects of scaling cellular agriculture production come together to form the finished product . They will likely be large tanks that would be like large brewery tanks . Currently, no large-scale bioreactors exist that would accommodate commercial scaling for cultured meat.
The first large-scale bioreactor for cellular agriculture could be a reality by 2020 . Research is currently investigating how to scale contemporary bioreactors and modify them for growing cultured meat .
In the future, a stable stem cell line will be produced by inducing stem cells from adult cells of the animal of interest. This cell line is stable and a constant source of stem cells so animals are no longer required in the production process. These stem cells are grown in an inexpensive animal-free cell culture serum in the proliferation system of a bioreactor. As the stem cells self-replicate and differentiate to form muscle fibers, these fibers detach from the scaffolding that holds stem cells in the proliferation system and moves over to the maturation system of the bioreactor.
There is a long way before this idealistic situation can become a reality. The topics discussed are key production challenges that cellular agriculture companies need to overcome. It is important to note that not all topics need to be solved before the release of the first products. Starting with cultured ground beef or poultry avoids many of the issues discussed .
By 2020, Dr. Post would like to have the cost for a Mosa Meat burger patty down to $10. Within five years of that, with the help of scaling production, Dr. Post would like his cultured meat patty to cost as much as the least expensive meat on the market . Eventually, the production process of cell ag products will reach a state where it can compete with the prices of conventional livestock animal products.