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Over the last five years, unbeknownst to consumers, the use of gene-edited yeast has quietly “swept through” the craft beer industry, WIRED reported.

Berkeley Yeast, a San Francisco-based biotech startup, uses CRISPR technology to tweak yeast cells, making gene-edited yeast that can do things natural yeast can’t — like increase flavor stability, or add new flavors such as guava, passionfruit, pineapple or a “tropical melange.”

The new yeast promises to solve many of the problems craft brewers encounter. Berkeley says its yeast varieties can eliminate problems from diacetyl — a compound that can form in hoppy beers, making them taste like “movie-theater popcorn” — cut long brew times and make it easier for brewers to produce “popular but difficult-to-achieve flavor profile(s).”

But the gene-edited yeast’s biggest selling point, according to the company, is that it can make beer taste like hops — a key beer ingredient and the signature flavor of most craft beer — without using any hops. That matters, the company says, because hops is a water-intensive crop that uses a “large amount” of natural resources.

“My hope,” founder Charles Denby, Ph.D., told Berkeley News, “is that if we can use the technology to make great beer that is produced with a more sustainable process, people will embrace that.”

But critics told The Defender the technology carries serious known and unknown risks for human health. And besides, they said, the amount of resources needed for hops production is “incredibly small” compared to most industrial food crops — and the gene-editing technology itself is resource-intensive.

Mark Kastel, executive director of Wisconsin-based OrganicEye, said these technologies “create novel organisms that have never been previously part of the human diet. And the real kicker here is there’s never been any testing done on humans and human health.”

Claire Robinson, managing editor of GMWatch, said she sees “a disturbing trend whereby farming involving soil, free solar energy and honest labor is being disparaged as environmentally destructive and bioreactor technology — involving high-tech processes and genetic engineering — is hyped as being environmentally friendly.”

“This of course is nonsense,” Robinson said. “Bioreactor technology is energy-hungry and resource-hungry and runs counter to any sustainability goals.”

Robinson, who is based in the U.K., added:

“I have never heard anyone in Europe complain that their beer had an unpleasant buttery flavor. Perhaps the U.S. brewers should examine every stage of the production process to work out what the Europeans are doing differently.”

Jacob Pressey, a regenerative grain and hops farmer, told The Defender he didn’t think “genetic modification of organisms that are intended for human consumption is ever a good idea,” and that the money and resources spent on developing these strains was “wasteful.”

“There are hundreds of yeast strains that already exist and they produce many different flavor compounds for brewers to choose from,” Pressey said, “so I don’t see the point of trying to reengineer their genetics,” he added.

WIRED reported that despite such concerns, craft brewers across the U.S. have tentatively started trying out Berkeley strains for some or all of their beers.

Berkeley declined to share the number of breweries using its strains, but craft brewers told the outlet “that everyone they know in the trade is either using the startup’s strains or considering it.”

Breweries such as Alvarado, Temescal, Watts Brewing Company, Cellarmaker and Lagunitas — now owned by Heineken — all profess to use Berkeley’s CRISPR yeast in their breweries.

Because craft brewing only makes up one-quarter of the U.S. market, WIRED wrote that “to really hit the big time Berkeley Yeast will have to win over the largest multinational beer corporations such as Anheuser-Busch InBev and Heineken.”

Denby told WIRED that major beer companies have been testing the startup’s yeast. Somebody is going to jump in, and we are kind of standing on the precipice of that,” he said. “I don’t know who it’s going to be, but once they do I think it’s going to become commonplace.

CRISPR technology funded by Bill Gates and venture capitalists

WIRED described Berkeley Yeast’s beginnings as a classic, mythical start-up story about a couple of smart post-docs experimenting in their spare time in a California garage, hoping to invent a product to transform an industry and save the environment.

Denby, microbiologist and home brewer, said he developed the gene-edited yeast when he was home-brewing beer in his Berkeley garage and realized the hops were both expensive and resource-intensive.

But the WIRED article doesn’t mention that the company started in 2017, with a $225,000 grant from the National Science Foundation, which awarded it another $1,449,999 the following year.

In March 2018, Denby, company co-founder Rachel Li and other scientists published a paper in Nature Communications that explained the CRISPR gene-editing technology they used to create yeast strains using DNA sequences from mint and basil plants.

CRISPR — which stands for clustered regularly interspaced short palindromic repeats — acts as a “precise pair of molecular scissors that can cut a target DNA sequence, directed by a customizable guide.”

The technology allows scientists to edit sections of DNA by “snipping” specific portions of it and replacing them with new segments.

Gene editing is not a new concept, but CRISPR technology is viewed as being cheaper and more accurate.

Using CRISPR, Denby and his colleagues engineered yeast to produce terpenes — organic compounds known for their strong odor — that could mimic the aroma and flavor usually produced through standard dry hopping of beer. Then they incorporated recombinant DNA from other edible plants to make those qualities even stronger.

The paper also reported that in the taste experiments, they ran on employees at Lagunitas Brewing Company in California, tasters said the CRISPR beer was hoppier than a comparable control beer.

By June — just three months after the paper was published — the company had met with the U.S. Food and Drug Administration (FDA) and submitted its application to have the CRISPR yeast classified by the FDA as “generally recognized as safe” so they could start marketing their product.

Since then, the company has grown, selling its yeast to a growing number of craft breweries.

In May, the company raised about $10.5 million in its first major round of external investor funding. Primary investors include Anterra Capital, Finistere Ventures and Refactor Capital — venture capital firms that all focus on funding the biotech-based transformation of the global food system.

Anterra and Finistere also co-invest in at least one other major biotech venture with the Bill & Melinda Gates Foundation.

Gates has been one of the most enthusiastic proponents of CRISPR technology both, individually and through the Gates Foundation.

In the field of biotechnology, the Gates Foundation has provided CRISPR-related grants to CRISPR Therapeutics and Edge Animal Health, and to a firm known as Acceligen, which “provide[s] small-scale dairy producers in sub-Saharan Africa access to highly-productive and well-adapted cows to increase their income.”

‘This is the Beyond Meat of beer’

WIRED reported that resistance to the CRISPR yeast comes from some hop farmers worried they will be displaced, and some consumers with holdover “GMO skepticism from the 1990s and early 2000s.”

But a large body of scientific research raises serious questions about the impacts of genetically modified organisms, or GMOs — of which CRISPR is one type — on human health.

Kastel said part of the problem is that there are no data on the long-term health effects of gene-edited foods, because there has been no testing and because they are so new.

There is also the problem, he said, of “the potential release of novel organisms into the environment.”

Robinson said there were already serious problems with GM yeast in the past — even prior to the introduction of CRISPR — where the modification process produced novel toxins.

She said:

“For example, a strain of bakers’ yeast engineered to be a better fermenter, was found to unexpectedly produce high levels of a toxin, methylglyoxal, a known carcinogen.

“Fortunately this was discovered in time and not commercialized.

“A less fortunate outcome involved the marketing of tryptophan as a sleeping aid produced from GM bacteria, engineered to jack up production. Thousands of people who ingested the engineered tryptophan became ill with a new muscle-crippling disease (eosinophilia-myalgia syndrome). Dozens died.

“The suspected toxin was present at less than 0.1% of the final marketed product, having survived stringent purification processes during manufacture.”

Robinson told The Defender she hoped the Berkeley scientists knew of these risks.

“We can only hope that the manufacturers of the GM yeast strains have tested for the presence of novel toxins that may carry through to the final marketed product,” she said.

In 2018, The New York Times ran an article on Berkeley Yeast that highlighted potential consumer skepticism. It asked, “If Americans will eat a burger with no meat, will they drink a beer without hops?”

But since then, Americans’ willingness to eat “a burger with no meat” has been put into question as research emerges that fake meat products such as Impossible Burger and Beyond Meat contain chemicals that may not be safe to eat.

And Bloomberg recently chronicled the rapid rise and fall of the fake meat industry, calling it “a flop.”

The Times wasn’t the only one to draw the comparison between the genetically modified ingredients in beer and fake meat.

A brewer told WIRED that a skeptical hops farmer raised a similar concern at a hops conference, saying growers opposed the GM yeast. “This is the Beyond Meat of beer,” he said.

Kastel agreed. He said it is paradoxical that these foods are gaining popularity given the latest science on human health.

“We’re on the cusp of substituting technology and products created in a laboratory for nature, farms and farmers. All these potential meat and dairy analogs and so-called ‘cell-cultured’ foods, these are being produced in stainless steel sterile laboratories.”

Kastel added:

“This is at a time when we’re learning more and more — it’s an emerging area of science — about how important the diversity and health of our microbiome is to our general well-being and our immune systems.

“And so I don’t know that we can survive on sterile factory-produced food. And, and this is just one more little element in trying to shift what we consume from what we’ve commonly called food to an industrial product.

“It’s the totality of the potential impacts here that we have to be concerned with.”

How ‘resource-intensive’ is hops, really?

Existing literature on the company, from the Nature Communications paper to the WIRED article to its own website, implies that one key problem addressed by the CRISPR yeast is the problem that hops production uses a lot of water.

For example, the Times wrote that hops “are a resource-intensive crop, requiring large amounts of water and sunlight to grow. The irrigation of hops in the United States alone requires more than 260 million gallons of water a year.”

It is true that hops are a water-intensive crop. But hops production makes up only a small portion — less than 59,000 of a total 893.4 million acres — of land in the U.S. under agricultural production.

And crops such as industrial corn that goes into animal feed use massive quantities of water — a high-yielding corn crop uses about 600,000 gallons of water per acre.

But Pressey, who runs Humboldt Regeneration Brewery & Farm, said the problem of resource-intensive agriculture was about the industrial system, which needs to be transformed into a more sustainable one.

“The answer to our very big problem of this extremely energy-intensive industrialized agriculture system that we rely on is not the genetic manipulation of yeast cells in a lab,” he said. “The answer is creating more energy-efficient and sustainable food-production systems.”

Kastel added that for the sizable number of people who want safe and natural foods, looking for the organic label is the best protection.