In news to delight eco-friendly hipsters the world over, boffins at the University of California, Berkeley, have come up with a way of creating hoppy craft beer without recourse to, er, hops.
Hops, while key to imparting flavour and aroma, are a bit of an environmental disaster, with 100 billion litres of water required to irrigate the crop in the US alone.
And, as beer aficionados are all too aware, hops can subtly change in flavour from year to year, resulting in some deeply unpleasant surprises.
The Berkeley boffins took brewer's yeast, which is used to ferment the beer, and added four new genes to give consistent hoppy flavours.
The resultant hop-free brew was put up against a control beer made with regular yeast and Cascade hops in a double-blind trial with employees from the Lagunitas Brewing Company enrolled as participants.
The results were that the hop-free beer was characterised as actually being more hoppy than the control brew with notes of "orange blossom" and, er, "Fruit Loops".
More importantly, there were no unpleasant flavours.
Charles Denby, a former UC Berkeley postdoctoral fellow, used the CRISPR-Cas9 gene-editing tool to insert linalool and geraniol synthase along with two other genes to make the hop flavour.
The process is described in the published paper in Nature Communications.
As with traditional brewing, care had to be taken to ensure the mix was correct to get just the right balance of flavours with the exception that a software program was written to do the job rather than someone with a beard tipping bags of ingredients into a vat.
Denby – along with the co-author of the paper, Rachel Li – has since launched Berkeley Brewing Science to market the hoppy yeasts to brewers. The gene-editing technology offers the opportunity to include flavours not normally found in beer brewed in the traditional way.
As for whether that is a good thing or a bad thing... well, the truth will quite literally be in the tasting.
The Register reported on DNA-bothering boffins brewing custom beer back in 2017.
When we asked a beer-loving molecular biologist for an opinion on this new development, we received the reply: "The main technical hurdle was to manage to finely tune the expression of the introduced genes to achieve optimal (read: tasty beer) rather than maximal concentration of gene products.”
“I haven’t tasted the beer yet!”
So there you go. ®