Spacemilk Introduces a New Source of Protein: The World's First Protein Made From Baker's Yeast

The yeast that has raised bread for thousands of years now makes a complete protein that matches whey on quality, without the dairy

November 2026 — Animal or plant: for nearly all of history, that's where protein has come from. Spacemilk is adding a third. Spacemilk Complete Protein is the first protein made from non-GMO baker's yeast, and it's light on your stomach, matches whey on protein quality and is free from all 9 major allergens.

In the protein powder aisle, that's meant a trade-off. Whey is a complete protein, but it comes from dairy, and plenty of people find it hard to digest. Plant proteins are dairy-free, but most score lower on protein quality and digestibility (PDCAAS). Spacemilk found the best of both in baker's yeast: the protein quality of whey, without the dairy.

People have used baker's yeast to raise bread and ferment beer and wine across cultures and centuries. Now it gives us protein. Spacemilk grows yeast in water through fermentation, the same process behind sourdough and kombucha, then separates out the pure protein and turns it into a smooth powder. No live or active yeast remains. What's left is a complete protein with a PDCAAS of 1.0, a perfect protein quality score and the same as whey and egg. It's also vegan, with no dairy, soy or gluten.

Yeast protein has already been tested head-to-head against whey. In a 2024 double-blind randomized controlled trial, yeast protein, the protein in Spacemilk, matched whey for building lean muscle and strength in men over 40 doing resistance training. And because it's grown in water, not farmland, Spacemilk's protein has about a 95% lower carbon footprint than beef protein.

"Most protein powder comes with a catch: bloating, cramping, a heaviness you've been told to expect," said Walter Ross, founder and CEO of Spacemilk. "Spacemilk was made to be gentle, light on your stomach and obsessively clean. For years, protein meant choosing between whey and plants. We wanted to give people a new kind of protein that works for everyone."

As concern grows about heavy metals in protein powder, Spacemilk starts from a different place: no soil and no animals. Its protein is grown in water, in stainless-steel tanks, through a controlled fermentation process. Every batch is tested by an independent lab for heavy metals, including lead, along with pesticides, microbials and allergens, and every result is published by lot at spacemilk.com/pages/testing.

Each scoop has 20g of complete protein and 0g sugar. Spacemilk Complete Protein comes in Chocolate, Vanilla, Original, Pumpkin Spice, and Unflavored, and is available now at spacemilk.com, Target.com and Amazon. It arrives in Sprouts Farmers Market stores nationwide on December 28, 2026.

About Spacemilk

Spacemilk makes Complete Protein, the first protein made from non-GMO baker's yeast. Grown in water through fermentation, Spacemilk delivers 20g of complete protein per scoop with 0g sugar, is free from all 9 major allergens, and publishes third-party test results for every batch. Spacemilk is available at spacemilk.com, Target.com and Amazon.