Case Study 1 — The Cheesemaker Who Switched

Setting

A small artisan cheesemaker in northern Wisconsin, family-owned for three generations. The grandmother started the operation in 1956, when the family farm transitioned from milk-only to milk-and-cheese as a way to capture more value from a small herd. The grandson — call him David Lindstrom; the family is composite, drawn from several real Wisconsin operations — runs the business now, in 2026. About eighty hundredweight of cheese a week. Cheddar, Monterey jack, a few specialties. Sells to regional grocery, a few restaurants in Madison and Milwaukee, a long-distance mail-order business that has grown steadily since David started a website in 2011.

For the entire history of the operation, the family has used animal rennet — calf chymosin, sourced from a Vermont supplier whose grandfather started in the 1940s. Calf rennet has, for them, been not just an ingredient but a piece of cheesemaking identity.

In 2018, David's primary rennet supplier sent him a letter. The letter said the supplier was getting out of the calf-rennet business. The supply chain had become unreliable — fewer veal calves were being raised in the United States, the Vermont supplier's source farms had shrunk to three, and the price had risen by thirty percent over five years. The supplier was switching to recombinant chymosin from a major industrial enzyme producer (Chr. Hansen, the Danish biotechnology company that has been in the rennet business for over a hundred years). Would David switch with them, or find another animal-rennet source?

This case study is the story of David's six-month decision, and what happened in the cheese.

The technical question

David had two specific concerns about switching to recombinant chymosin.

The first concern was identity. He had grown up making cheese with animal rennet. His grandmother had made cheese with animal rennet. The label on his cheese had, for decades, said "with traditional animal rennet" — a phrase his customers seemed to value, especially the high-end cheese-shop accounts that sold his cheese to people who cared about provenance.

The second concern was technical: would the cheese taste the same?

To answer the technical question, David did what a serious cheesemaker does. He set up a side-by-side trial. For six months, he made matched batches every other week — same milk (his own herd's milk, the same cows, on the same forage), same starter cultures, same cooking schedule, same press, same affinage — varying only the rennet. Half the batches were animal rennet from his old supplier (he had bought enough to bridge the trial). Half were recombinant chymosin from Chr. Hansen.

He aged the cheeses for one month, three months, and twelve months. He tasted them blind, with three of his employees and two long-time customers helping. He sent samples to a sensory-evaluation lab at the University of Wisconsin's dairy science program for formal evaluation. He measured pH, moisture, fat, and protein on every batch. He kept notes.

What he found

At one month, the difference between the two batches was real but small. The animal-rennet cheese was very slightly more aromatic — perhaps a 5–10% difference in volatile-compound concentration, mostly in the short-chain fatty acids that develop during the early aging. The textural difference was undetectable.

At three months, the difference had narrowed. The aging process had built up secondary flavors that swamped the small initial differences in rennet chemistry. The two cheeses were within the noise of normal batch-to-batch variation — in fact, two batches with the same rennet, made one week apart, often differed more than a recombinant-rennet batch and an animal-rennet batch from the same week.

At twelve months, in the aged cheddars, David and his tasters could not reliably tell the two apart. The University of Wisconsin lab confirmed: the volatile-compound profiles converged with age. The protein degradation patterns, by gel electrophoresis, were essentially identical. The lactic acid bacteria population in the rind was the same. The salt distribution was the same.

David made his decision at month seven of the trial.

What he did

He switched.

He did not, however, simply substitute one for the other and pretend nothing had changed. He did three things instead.

First, he updated his label. The new label said "made with vegetarian rennet" — a phrase that is technically accurate (recombinant chymosin is from yeast or fungus, not from any animal), legally allowed, and, as it turned out, better received by his cheese-shop accounts than he had expected. Several of those accounts had been quietly losing customers to vegetarian-friendly cheeses; David's switch let them market him to a wider audience.

Second, he wrote a long, honest blog post about the switch. The post explained the trial he had done, the results he had gotten, the reason he was switching (supply-chain reality), and the conclusion that the cheese was the same. He posted it on his website. It got picked up by a few cheese-industry publications. Customer reaction was overwhelmingly positive — most people had not realized animal rennet was even an issue, and those who had cared appreciated the transparency.

Third, he kept making one small specialty product — a 24-month aged "heritage" cheddar that the family had made for several decades — with animal rennet. He sourced it, at considerably higher cost, from a different supplier in the Pacific Northwest who still maintained calf-rennet production. The heritage cheddar sold for about double the price of the regular cheddar, in small lots, mostly to a few dedicated customers. It paid for itself.

What he learned

David's takeaway, as he told it to me in 2024 — six years after the switch — was about the gap between what he had thought would matter and what actually mattered.

He had thought animal rennet was central to his cheese's identity. It was not. The identity of his cheese came from his herd, his pasture, his cultures, his aging caves, and his own twenty-five years of practice. The rennet was an enzyme. Switching enzymes did not change the cheese.

He had thought his customers would be upset by the change. They were not. Almost no one noticed. The few who did asked, and were satisfied by the explanation.

He had thought the technical change would require months of recipe adjustment. It did not. The recombinant chymosin he switched to had been engineered, over the previous several decades, to behave essentially identically to calf chymosin in cheesemaking — a deliberate design goal of the enzyme producers, which they had achieved.

What he had not anticipated was that the switch would open up his market — vegetarian-friendly cheese was a category he could now serve — without closing any meaningful market. His sales grew about 12% in the year after the switch.

He had also not anticipated the small specialty product. The 24-month heritage cheddar was, in some sense, his preserved tradition: an honoring of his grandmother's method, kept alive for the customers who specifically valued it, supported economically by the larger volume that had moved on to recombinant chymosin. It was, he said, "the way you keep the old thing alive — by also being willing to do the new thing."

What this case tells us

The case is small. One cheesemaker, one switch. But it illustrates something about how food technology transitions actually happen at the level of the working kitchen.

It happens slowly. It happens with side-by-side trials. It happens with tasting panels. It happens with blog posts that explain the reasoning. It happens with willingness to keep one foot in the old practice and one in the new. It happens, mostly, without drama.

The same pattern, scaled up, has been the story of the transition from animal rennet to recombinant chymosin in the global cheese industry over four decades. Supplier by supplier, cheesemaker by cheesemaker, customer by customer. By 2026, the great majority of cheese on US supermarket shelves is coagulated by recombinant chymosin. Few customers know. The cheesemakers who switched mostly do not regret it. The customers who specifically wanted animal rennet are still served, at higher cost, by smaller specialty operations. The heritage product survives because it is differentiated, valued, and economically viable.

This is, plausibly, the model for how the broader transition in food technology will happen. Cultured meat will arrive in some restaurants. Some chefs will switch some products. Some specialty restaurants will keep the conventional product, marketed as such, at a price premium. Most consumers will not know the difference. The transition will look more like David's six-month decision than like a revolutionary moment.

Analyze this

Imagine you are advising a small artisan operation considering a similar transition — switching from a traditional ingredient to a precision-fermented or cell-cultured equivalent. The operation could be a baker considering microbially-produced amylase, an ice-cream maker considering precision-fermented dairy proteins, or a charcuterie producer considering cultured pork fat.

1. What kinds of trials would you recommend they run, and over what time period?
2. What technical, sensory, and economic measures would you have them track?
3. How would you advise them to communicate the change to their customers, given that some customers will care and most will not?
4. Should they keep a "heritage" version of any product? Under what conditions does that strategy make sense, and under what conditions does it not?
5. The chapter argues that "new ingredient, same cook" is the right frame. In David's case, the cook (the cheesemaker) genuinely did not need to change his methods. But in some cases, the new ingredient will require new technique. Which kinds of new ingredients are most likely to require the cook to relearn? Which are most likely to slot in invisibly, the way recombinant chymosin did?