For many years I have studied yeast. The one we use to bake bread and make beer. But, I did not use it for studying fermentation. We used it because it is a good model for studying gene regulation: how the genes turn on and off.
Do you know that concerning gene regulation, there are a lot of similarities between human and yeast? Even though yeast is a single celled organism?
Do you know more than half of the knowledge of the gene regulation is obtained from studying yeast?
Do you know that there is yeast mutant library where every single yeast gene has been deleted one by one?
Do you know that two of the most studied yeast species are Saccryomyces cerevisiae (budding yeast) and schizosaccharomyces pombe (fission yeast). Their evolutionary distance is that of between human and fish? So, if some functional mechanisms are similar between these two yeasts, it is quite possible that these functional mechanisms are the same in human as well!
In conclusion: the simplicity, the genetic of art and the similarities with human (in some aspects) make yeast a good model system for the researchers.