Synthetic biology has created microbes that produce drugs, flavors, aromas and fuels. Now scientists have used the same tricks, with the help of CRISPR-Cas9, to get yeast to produce the flavor of hops. They added genes from mint and basil and used the yeast to brew a beer that tasters said had notes of ‘fruit-loops’ and ‘orange blossom,’ with no off flavors. The yeast helps brewers avoid expensive, highly variable and water-guzzling hops.