Last December, Believer Meats published a study in the journal Nature Food breaking down our lab-grown meat production process and detailing how it can be scaled. The top scientist at the Good Food Institute, a leading alternative protein think tank, called it "the most comprehensive study on cultivating meat production to date," while vegan business magazine vegconomist hailed the study's findings as "groundbreaking."
Authored by Believer Meats founder, president and CSO, Prof. Yaakov Nahmias and Believer team members, along with scientists at the Hebrew University of Jerusalem, the study addresses doubts about the scalability of cultivated meat, and counters claims that lab-grown meat companies can never overcome the science and tech hurdles blocking pathways to mass production.
To showcase a pathway toward scalability, the study dives into Believer's process of making lab-grown chicken and, step-by-step, explains how key elements of our production process are designed to slash historically high costs and maximize meat produced. Below, we summarize the six biggest takeaways from the study and translate key scientific findings.
1. (Some) lab-grown meat companies can scale cultivated meat
If there is one thing to take away from this Nature Food study, it's that there are ways to overcome legitimate hurdles to mass producing real meat that companies are already cultivating in labs from animal cells. The study acknowledges key hurdles to lab-grown meat production, and explains how Believer has found ways around them.
The lab-grown meat production challenge
Lab-grown meat production has historically come with a huge price tag. Those following the industry might remember that the world's first cultivated hamburger cost a whopping $332,000 to make in 2013. Since then, costs have dropped significantly, though not enough, according to some analyses.
One, for example, projected that cultivated mincemeat or nugget-style products would go for at least $50/kg ($23/pound) at grocery stores. Our study offered evidence to support Believer's projection that our lab-grown chicken will sell for about $3.30 per pound, roughly the same price as conventionally-raised chicken. How?
Believer's lab-grown meat production solution
Our entire lab-grown meat production process has been designed to cut costs and maximize the amount of meat we produce. To ensure Believer meat is widely accessible and not simply a pricey treat for the 1%, we had to think creatively about every step of our process, beginning with the cells we use.
Our choice of cells
All lab-grown meat is made with real animal cells, extracted from living animals via a biopsy. Many companies use stem cells because they proliferate forever and eliminate the need to constantly source new cells — a costly process that's not great from an animal welfare perspective.
But Nahmias points out that stem cells are unstable and "need a lot to be happy; they're like little prima donnas," he's said. Instead, we use low-maintenance fibroblast cells that multiply more quickly and cost significantly less money to maintain than cells other lab-grown meat companies use.
Case in point: the nutrient-rich solution or growth media required to cultivate animal cells costs about $69 a liter for stem cells, according to some analyses, while our media costs less than $5 a liter.
Our method of cell sourcing
We also found a safe, non-GMO way to source fibroblasts that proliferate forever, eliminating our need to constantly purchase cells sourced from living animals. Further down, you can read more about how this aspect of our lab-grown meat production, called "immortalization," works.
The fact that our cells proliferate in suspension
In order to transform a sample of "starter" cells into a big batch of animal cells, lab-grown meat companies must nurture them in a nutrient-rich broth that mimics blood inside an animal's body. We do this first in small flasks, and eventually in bioreactors, where they multiply and grow.
For years, scientists have used this process to cultivate cells for a range of purposes, including medical research and vaccine production. The quantity of cells produced in each bioreactor "run" depends on a range of factors including whether the cells need to adhere to a surface.
Cells that are "anchorage-dependent" can only grow in a bioreactor if they adhere to a surface, like microcarriers, tiny beads or particles used in bioreactors to cultivate these clingy cells. But a bioreactor can only support a relatively small number of cells per liter with microcarriers.
At Believer, we've adapted our cell lines to anchorage-independent growth, which means they can proliferate in suspension — floating, if you will — inside our bioreactors, without the need for surface area. Bioreactors can support many more cells per liter when the cells can grow in suspension.
Our bioreactor processes
The process of cultivating cells at larger scales typically involves adding growth media and cells to a bioreactor, allowing them to "cook," and then harvesting the final product by separating the cells from the waste they naturally generate.
The problem with this method is that cellular waste limits the amount of cellular biomass any bioreactor can produce in a single run. A common workaround involves adding fresh media and removing waste through a process called perfusion, which enables cells to grow at higher concentrations. But perfusion can be costly since it requires much more growth media.
At Believer, we have developed a more cutting-edge process, which involves continuously clearing out waste, recycling the media through our patented rejuvenation system, and feeding that recycled media back into the bioreactor again. This process allows us to recycle a significant percentage of the waste media and cut down our water usage.
All of these processes together result in our animal cell biomass reaching densities that surpass commonly cited projections that estimate lab-grown meat companies can only achieve a maximum density of 22 to 65 billion cells per liter.
In short, this all means that we can make more animal biomass — the meaty base of cultivated meat — in each bioreactor run for less money than companies using more traditional methods.
2. Our process of immortalizing animal cells is non-GMO, and safe
One issue with our easy-going fibroblast cells is that they don't proliferate forever, like stem cells do; they die. One technique often used to "immortalize" cell lines, or prevent cells in a sample from dying off, is to genetically modify them. But regulators and consumers aren't crazy about this and neither are we.
Genetic modifications can lead to unintended mutations we want to avoid, so we developed a patented technique to identify and isolate rare but naturally-occurring "spontaneously immortalized" cells in each sample (cells that don't die) and we use those as the foundational ingredient in our cultivated meat.
3. Fat is key
Beyond cost, the commercial viability of lab-grown meat hinges on consumers accepting that these products are … meat. That means they must not only look like meat, they must cut like meat, cook like meat, and have the same overall sensory profile of a chicken strip, burger or lamb kebab.
We understand that the key to hitting all these notes is mastering our products' fat profile. To accomplish this, we use food grade molecules (safe for use in foods) to spur our cells to accumulate fat. These cells are combined with plant proteins and other ingredients to create cultivated meat with an authentic sensory profile.
4. Our lab-grown chicken passes the taste test
Beyond demonstrating that we can cut production costs to a level that is commercially viable using safe, non-GMO processes that prioritize our products' sensory profile, the Nature Food study also provided evidence that our lab-grown chicken passes the taste test. To assess this key criteria, the study's authors conducted three taste tests.
In the first, 13 people (84% identifying as meat eaters) graded our lab-grown chicken on a scale of 1 to 5 and indicated how likely they would be to replace their meat of choice with Believer chicken. Participants gave our chicken an average score of 4.5 and indicated that their likelihood of replacing their meat of choice with our chicken was 8 on a scale of 1-10.
The following two tests conducted with 30 people found that our fat cells improved the "flavor-related attributes" of our lab-grown chicken and that most participants preferred our meat over a soy-based alternative.
5. Our process delivers on nutrition too
One of the exciting aspects of lab-grown meat production is the opportunity it gives companies to finetune their products' nutritional profile. The Nature Food study dug into the nutritional value of our lab-grown chicken and found that it was "similar" to farmed chicken, but had some unique advantages too.
Our lab-grown chicken strips had 22% less saturated fat and 37% less cholesterol than farmed chicken. The sodium found in the soy protein we use to cultivate our chicken strips elevated our chicken's sodium content, but we continue to finetune our processes to ensure our products deliver on both sensory characteristics and nutrition.
6. The environmental hype is not necessarily overblown
The production of farmed meat accounts for an estimated 60% of greenhouse gas emissions from global food production and is linked to other serious environmental issues, like deforestation. Reasonably, climate advocates are keen to support alternatives to conventionally-farmed meat.
Many have had their sights set on lab-grown meat production, which, according to projections, could significantly slash livestock land use, and emit a fraction of the greenhouse gasses produced in conventional meat supply chains.
All of this hinges on cultivated meat scaling, which hinges on lab-grown meat companies overcoming legitimate technological challenges and finding ways to drive down production costs. Some critics say the challenges are insurmountable and have declared the industry un-scalable — doubts our founder, Prof. Nahmias, has addressed.
"The highest densities for stem cells in bioreactors are about 67 million cells per ml," he's explained. "If you use that yield then [critics] are correct. You are going to end up with a product that costs you hundreds of dollars per kilogram."
"The devil is in the details,” he said, noting that not all lab-grown meat production processes are fully scalable. “However some clearly are."