Cauldron Ferm has an unlikely origin story, as startups go. Its core technology might be traced back to the Nineteen Sixties, or perhaps the Seventies. The precise start is a bit hazy, actually. What is understood is that David and Polly McLennan had a dream of feeding the world using protein grown from microbes.
The pair knew they needed to enhance the method, which was pricy and time consuming. Most fermentation happens in batches. Picture a brewery or a vineyard. Ingredients go in and the microbes work for some time, but then the method stops when it’s time to take out the finished product. It really works for alcohol because booze commands a premium price. Food, though? That should be cheaper.
Still, the McLennans stuck with it, starting a small business that may over the course of 40 years refine their approach to continuous fermentation, which turns microbes into assembly lines able to cranking out products uninterrupted.
“We didn’t know what we had,” Michele Stansfied, co-founder and CEO of Cauldron Ferm, told TechCrunch. But eventually, Stansfield who arrived on the McLennans’ company in 2012, realized that they had greater than initially thought.
“We didn’t understand the challenge of continuous fermentation for synthetic biology,” Stansfield said. But when she did, she sought to rework the corporate from a small fee-for-service operators to a fast-moving startup. “At that time, I raised a seed round and bought the IP, physical, and business assets.”
Cauldron has now raised $13.25 million in a Series A2 round that was led by Fundamental Sequence Ventures with participation from Horizons Ventures, NGS Super, and SOSV, the corporate exclusively told TechCrunch. It had previously raised $6.5 million in 2024. Cauldron plans to make use of the funding to “increase the technology moat,” Stansfield said.
The corporate calls it’s technology “hyper fermentation,” which helps keep microbes of their maximally productive state. It might probably work in existing batch fermenters with a number of modifications to the ability to accommodate the method. Cauldron’s customers bring their very own microbes and strains, and the startup works to tweak their growing conditions, including nutrients, to maintain them humming.
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Currently, Cauldron is concentrated on producing fats and proteins, including whey protein, “a product that may just slip into supply chains,” Stansfield said, though she adds there are more products the corporate has its eyes on.
“Sixty percent of all inputs to global economy might be produced from biology,” she said. “Food was where we began, but now we’re starting to actually diversify.”