More than 90 percent of collagen and gelatin on the market comes from hogs and cattle, a byproduct of the slaughter industry. The goal of Geltor’s theoretical experiments wasn’t just to generate hype but to convince potential clients they could make products the current supply chain couldn’t. “What if you weren’t constrained by what kind of animal is available to source your collagen?” Dr. Lorestani recalled asking. Then he suggested one mammal in particular, which is how Geltor settled on its first creation: HumaColl21, which the company calls “a virtually colorless and odorless solution.”

In 2019, the Korean company AHC released an eye cream containing HumaColl21. Orora Skin Science, based in Canada, followed with creams and serums in 2021. In the past two years, Geltor has released biologically similar marine collagen and human elastin (as the name implies, a particularly stretchy protein) for skin care, as well as a poultry-like collagen intended for use in nutritional supplements. Microbes growing in giant fermenters express each of these collagens, which are strained and refined into pure protein. “The protein is just like what you would find in the original source,” Dr. Lorestani said. (The third-party IGEN certification program confirmed there was no detectable genetic material in the final product.)

A $91.3 million investment round in 2020 allowed Geltor to ramp up production from 35,000 liters in 2019 to 2.2 million liters in 2021, which is still a relatively small amount. Tiny bottles of luxury eye creams require very little HumaColl21; large shampoo bottles and jars of collagen powder require more. Enough gelatin to supply Midwest potlucks with vegan Jell-O salads would require exponential growth.

Those limits have determined the company’s commercial path. “The volumes of product required for the beauty and personal care customers are different than what are required for food and nutrition customers,” Dr. Lorestani said.

Despite all that investment, there are skeptics. Julie Guthman, a geographer at University of California, Santa Cruz, who investigates Silicon Valley’s forays into agriculture and food, questions the “magical disruption” behind the alternative-protein industry’s promises.

“There’s this idea that if you produce protein from cells or fermentation in a lab, somehow it removes us from land-based meat production,” she said; these companies still require energy, metal and food for the microbes themselves. And, she noted, there’s little transparency into their environmental claims, since their patented processes are closely guarded secrets.