I first saw the post about this on Jeff Alworth’s Beervana Blog Facebook group, and then it seemed to be popping up everywhere. Apparently, some scientists in California used gene splicing to allow yeast to make one of the aroma oils from hops, using genes from other flowers and plants that make those compounds.
Here is a link to the actual research paper, posted on Nature.com
Industrial brewing yeast engineered for the production of primary flavor determinants in hopped beer It’s a bit to chew through, but I’d recommend reading at least the results section. It does work, to a certain extent, but the commercial viability of it is probably very limited.
What followed was a series of newspaper type articles, ranging from super clickbait, to quasi scientific that briefly touch on the results and then make wild assumptions about what this technology means. This is one of the major things that drives me bonkers when non scientific people try to make judgments based on science they don’t understand but assuming the science supports them, when sometimes it’s the exact opposite.
First is this article from Quartz which is so poorly written it’s painful to read. The main issue here is that they roll out the old “Hoppy pale ales and IPAs were made to survive the trip overseas” myth which has long since been busted, and then they claim that hops are no longer needed as a preservative like they were back then. We may have refrigeration now and better packaging techniques, but beer spoilage is still a major fight every brewer faces. Hops anti-microbial properties are still very much in play. Sour beer producers use aged hops that impart almost no bitterness or flavor/aroma specifically for the control of which bacteria and yeast they want to grow and flourish and which they want to inhibit.
Next, have an article from TheTakeout which is very short and barely mentions the research at all, but a couple things. First, the title of the article “New Beer yeast could make hops irrelevant” This is a huge leap (that all the articles make) that suddenly we could make beers without hops. That doesn’t work for several reasons, one is that you literally cannot make beer without hops, legally. It has to contain hops to be considered beer, otherwise it’s a flavored malt beverage (think Zima, Mikes Hard, etc). Of course those rules can be changed, but for now that’s how it is. Also, as mentioned above, hops do play other roles than just bitterness or just flavor.
One thing that really gets me about the above article, and even this mostly scientific one from Smithsonian Magazine is the phrase that “some terpenes could mimic the taste of hops”. I think this is where a lot of people get riled up about GMOs or things like this as being un-natural. It would be much more accurate to say that some plants contain the same terpenes as hops. Limonene, one of the major aroma compounds in citrus fruits, is also found in hops and in marjiuana. It’s not just that hops or weed can “smell like” orange or lemon, they literally contain the exact same compound, produced in an identical, or similar, pathway. We associate flavors with certain things, usually a food product since that’s what we learn first as kids, but other things contain the same compounds.
A few things, in closing, about this from a commercial prospective. Yeast is already more expensive than hops, so I don’t imagine there will be much cost savings buy engineering yeast to replace hops. Plus, this yeast I’m sure would cost a lot more than standard brewers yeast. Second, the articles talk about hop flavors changing from year to year with crop changes, but yeast is not stable either. Yeast mutate over time, and after a handful of generations they may not produce these compounds anymore, or not at the same levels. More research would need to be done (and probably will be) to see how stable these genetic changes are. Lastly, these yeast were designed to produce one hop oil only. Hops, like flowers and spices like vanilla, contain hundreds (if not thousands) of flavor compounds. Vanilla is a great example. The main compound we associate with vanilla is vanillin. Artificial vanilla uses only vanillin, whereas real vanilla may be 90% vanillin, but has many other compounds to round out the flavor profile. Most people can immediately tell the difference between natural and artificial vanilla. Vanillin is found in oak, which is what gives whiskies and barrel aged beers that hint of vanilla, but on its own it just doesn’t live up to the real thing. They compared the yeast made beer with a single hop beer, Sierra Nevada Pale ale, and it compared favorably, but you could never mimic a complex hoppy beer like Boneyard RPM which uses 6 or 7 different hop varieties.
In my opinion, this is novel research and probably teaches a lot about yeast genetics, but this has virtually no commercial application, at least for now. 20 years from now, who knows, but as usual the websites that want to claim that we can make beers without hops “right now!” are way off base.
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