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Cauldron Ferm has turned microbes into nonstop assembly lines | TechCrunch

2026-03-24 · 00:00 UTC ·Tim De Chant ·2 min read

Brief

Cauldron Ferm is turning an older continuous-fermentation concept into a synthetic biology manufacturing platform by keeping customer-provided microbes and strains continuously productive instead of cycling through batch runs. CEO Michele Stansfield, who joined the predecessor business in 2012 and later acquired its IP and assets, says the new capital will deepen the company’s process moat as it expands from food proteins into broader biologically produced industrial inputs.

Why it matters

Cauldron Ferm commercializes a continuous-fermentation process refined over roughly 40 years by David and Polly McLennan, replacing stop-start batch production with uninterrupted microbial production aimed at lowering the cost of biologically made food ingredients.

Key details

  • The company raised a $13.25 million Series A2 led by Main Sequence Ventures, with Horizons Ventures, NGS Super, and SOSV participating; it had previously raised $6.5 million in 2024.
  • Cauldron’s “hyper fermentation” keeps microbes in a maximally productive state, can retrofit existing batch fermenters with limited facility modifications, and is currently focused on fats and proteins such as whey protein for easier insertion into existing supply chains.
Cleaned source text

title: Cauldron Ferm has turned microbes into nonstop assembly lines | TechCrunch

author: Tim De Chant

content_type: article

publication: TechCrunch

published: 2026-03-24T00:00:00

source_url: https://techcrunch.com/2026/03/24/cauldron-ferm-has-turned-microbes-into-nonstop-assembly-lines/

word_count: 420

Cauldron Ferm has an unlikely origin story, as startups go. Its core technology can be traced back to the 1960s, or maybe the 1970s. The exact start is a bit hazy, actually. What is known is that David and Polly McLennan had a dream of feeding the world using protein grown from microbes.

The pair knew they needed to improve the process, 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 a while, but then the process stops when it’s time to take out the finished product. It works for alcohol because booze commands a premium price. Food, though? That needs to be cheaper.

Still, the McLennans stuck with it, starting a small business that would over the course of 40 years refine their approach to continuous fermentation, which turns microbes into assembly lines capable of 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 at the McLennans’ company in 2012, realized they had more than initially thought.

“We didn’t understand the challenge of continuous fermentation for synthetic biology,” Stansfield said. But when she did, she sought to transform the company from a small fee-for-service operators to a fast-moving startup. “At that point, I raised a seed round and acquired the IP, physical, and business assets.”

Cauldron has now raised $13.25 million in a Series A2 round that was led by Main Sequence Ventures with participation from Horizons Ventures, NGS Super, and SOSV, the company exclusively told TechCrunch. It had previously raised $6.5 million in 2024. Cauldron plans to use the funding to “increase the technology moat,” Stansfield said.

The company calls it’s technology “hyper fermentation,” which helps keep microbes in their maximally productive state. It can work in existing batch fermenters with a few modifications to the facility to accommodate the process. Cauldron’s customers bring their own microbes and strains, and the startup works to tweak their growing conditions, including nutrients, to keep them humming.

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Currently, Cauldron is focused on producing fats and proteins, including whey protein, “a product that can just slip into supply chains,” Stansfield said, though she adds there are more products the company has its eyes on.

“Sixty percent of all inputs to global economy can be produced from biology,” she said. “Food was where we started, but now we’re starting to really diversify.”