San Francisco-based food technology startup Perfect Day has developed vegan whey protein using a fermentation process that makes it molecularly identical to animal-based whey. Whey is traditionally a byproduct of the dairy-cheese-making industry and a common ingredient in food products such as energy bars and protein powders. To make the protein, Perfect Day co-founders Ryan Pandya and Perumal Gandhi print a cow’s DNA sequence using a 3D-printer and insert it into a strain of yeast obtained from the United States Department of Agriculture. The yeast is then fermented to make milk proteins (whey and casein). The process is similar to growing slaughter-free meat from animal cells in a laboratory setting, but is considered acellular because there are no cells in the end product. Last week, Perfect Day announced a partnership with food-processing giant Archer-Daniels-Midland Co. to manufacture the whey ingredient on a commercial scale, which will make the startup the first in the world to produce animal-free dairy protein on a large scale through fermentation instead of farmed animals. “We’re one step closer in a big way to making this real,” Gandhi told media outlet Fortune. Perfect Day expects to sell the proteins to the food industry as an ingredient in 2019.