Lab-grown meat has grabbed a lot of headlines in recent years. Dutch scientist Mark Post infamously produced the first lab-grown hamburger in 2013 to the tune of $325,000. But Post’s costs have since dropped precipitously, and one cultured-meat startup, Memphis Meats, has said it expects to have a product in stores by 2021.

However, this new food landscape extends well beyond meat. In the Oakland biohacker space, biologists, coders, and other volunteers with the Real Vegan Cheese project are figuring out how to produce the real thing, and they’re keeping their findings open-source. In the startup arena, Perfect Day is racing to get their cow-free milk to market, Clara Foods is creating egg whites without eggs, and Geltor is making collagen in the lab. Bethencourt has supported these and other innovative food startups through IndieBio, an investment group and business accelerator he cofounded in 2014.

What all these projects have in common is that they’re harnessing the fermentation process to make animal protein. “We’ve been using that technology for thousands of years,” said Bethencourt in a recent talk. “Now we’re starting to get sophisticated with it.”

Producing animal protein in a lab looks like making beer, but with the help of a little synthetic biology. Scientists genetically modify yeast with a chunk of DNA that tells the microbe what protein to make. They then “brew” the yeast with nutrients in a bioreactor and isolate the resulting proteins. In other words, microbes become factories that churn out the same substances that we now rely upon sentient beings to produce.

In the case of Perfect Day, after isolating the yeast-derived cow’s milk protein, they add in nutrients—as well as plant-based sugars and fats—to achieve texture and flavor similar to those of milk from an udder. Unlike other milk substitutes, their milk doesn’t need starches, gums, and stabilizers, says company CEO Ryan Pandya, and it can be made into other higher-value products such as cheese and yogurt.