With the production of lager, the same few yeast strains have been used in the production of lager for centuries. Here lager has fallen behind beer. Now, some new strains are finally emerging.
The craft beer “revolution” has been something of a success in recent years with many micro-breweries opening up offering new and enticing flavors. However, with lager the same flavour developments have not occurred. The vast majority of lagers are produced by a yeast called Saccharomyces pastorianus, which is a different species to the type used to craft ales.
As to what is the difference between beer and lager, this has been a longstanding matter of discussion. Essentially lager is beer, and the difference is actually between ale and lager as the two main branches of the beer family tree.
The two types are differentiated by the type of yeast used. There are ale yeasts (which are quite diverse) and lager yeasts (for which there are fewer types.) The type of yeast used affects the temperature at which the beer is fermented. Ales are fermented at warmer temperatures (55 to 70 degrees Fahrenheit; whereas lagers are fermented at cooler temperatures (38 to 50 degrees Fahrenheit). The cooler temperature leads to fewer esters and less aroma, making lagers less flavorsome than ales. However, it also leads to a more refined process, leading to lagers tasting smoother than ales.
The search for new yeasts to use in lager production has been led by VTT Technical Research Centre of Finland Ltd. The food research body has spent a considerable amount of time developing new fungi for the brewing process.
To do this, the food technologists have gone down the hybridization route (creating a yeast variant based on two different strains). The new yeasts developed have been shown to effectively accelerate the wort fermentation process and improve the production of ethanol. The hybrids are additionally more tolerant to cold temperatures and settle better after fermentation than their predecessors.
For lager-lovers the new hybrids should be commercialized soon and the fruits of these labors could be available soon.
The new yeast development has been published in the Journal of Industrial Microbiology & Biotechnology. The research is titled “New lager yeast strains generated by interspecific hybridization.”
