Beer is one of the most popular beverages in the world, and with its wide variety of distinct tastes, scientists decided to pour a pitcher and figure out how the flavors are so distinctly delicious. Belgium researchers from the Flanders Institute for Biotechnology, set out to see why beer tastes so good to us, and published their findings in the journal Cell Reports.

It all comes down to the yeast — a living metabolizing, reproducing organism, and also the most important ingredient in beer. It is responsible for converting sugar into alcohol and carbon dioxide in the fermentation stage, and is ultimately what determines the flavor of the beer.

"The importance of yeast in beer brewing has long been underestimated,” the study’s coauthor Kevin Verstrepen, a research scientist from VIB, said in a press release. “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 flavor, which previously often was attributed to differences in the soil.”

Yeast may be the answer to why wine has variety in delicious tastes, and it may have nothing to do with the type of soil the grapes are grown in at all. There are thousands of varieties and different strains of yeast, which is why through the carbonation process beer can arrest a wide variety of aromas and engage the senses from one stout to the next. For thousands of years, humans have been producing bread, beer, and wine with yeast, so researchers decided to look into the role of yeast cells. It turns out the conversion from sugars into alcohol into carbon dioxide is much more complex, producing several aroma compounds during the process. Researchers are still not sure why the yeast chemicals produce these specific chemicals, but they do know that’s why we find them delicious. They lock into beer, while in wine the gas escapes and envelope the taste buds in completely different ways.

Researchers watched how flies reacted to the fruity chemicals produced by yeast cells and found them to be particularly attracted to the ATF1 yeast gene. When they created mutant yeast cells without the ATF1, the flies were no longer attracted to the yeast and instead gravitated toward the normal yeast cells. In 2012, a Gallup poll found roughly two-thirds of the American population drink beer regularly with an average of 4.2 drinks each week. According to the Brewers Association, as of 2013, the beer market is a $100 billion dollar industry, confirming our love for the liquid bronze gold.

"Flies are strongly attracted to normal yeast cells, when compared to mutant yeasts that don't produce esters,” the study’s lead Emre Yaksi, the neuroscientist in charge of the fly experiment, said in a press release. “Knowing that esters make beer taste good, it seems that the same flavors that allow us to enjoy our beer, probably evolved to attract flies and to help yeast disperse into broader ecosystems."

Source: Verstrepen KJ, Yaksi E, Hassan BA, Wenseleers T, Michiels J, Meester LD, Cools TL, Franco LM, and Chstiaens JF. The Fungal Aroma Gene ATF1 Promotes Dispersal of Yeast Cells through Insect Vectors. Cell Reports. 2014.