Beer's unique smell designed to attract fruit flies, study reveals

A new study has revealed that beer yeasts produce chemicals that mimic the aroma of fruits in order to attract fruit flies that can transport the yeast cells to new niches.

It was also revealed that these volatile compounds are also essential for the flavour of beverages such as beer and wine.

Researcher Kevin Verstrepen, said that the importance of yeast in beer brewing has long been underestimated. But recent research shows that the choice of a particular yeast strain or variety explains differences in taste between different beers and wines. In fact, yeasts may even be responsible for much of the "terroir", the connection between a particular growing area and wine flavour, which previously often was attributed to differences in the soil.

Yeast cells also produce several aroma compounds that are key for the taste, flavour and overall quality of beer and wine. In fact, different yeasts are producing different amounts of these aroma compounds. Whereas the importance of yeast aroma production is now fully appreciated. The reason why yeast cells would make these special, volatile chemicals remains mysterious.

The fruity volatiles produced by yeast cells are highly appealing to fruit flies, which allows some yeast cells to hitch a ride with the insects, who carry the otherwise immobile microbes to new food sources.

Moreover, deleting ATF1, the key yeast gene driving aroma synthesis, all but abolishes the attraction of flies to the mutants. Moreover, the brain activity in flies that are exposed to such aroma-mutants is very different from that in flies exposed to normal, fruity yeasts.

The study was published in the journal Cell Reports.