H-optimistic research?

An international team of researchers, including some from Cork, have discovered the origins of the yeast responsible for making lager beer.

The origin of the world’s most popular beer may have inadvertently come about due to the death of a childless German nobleman, an international team of researchers have discovered, have today, Thursday, revealed.

Combining historical research with modern science, a team of scientists from the Technical University of Munich in Germany and UCC have uncovered have said they know the likely genesis and path to world dominance of Saccharomyces Pastorianus, the yeast responsible for producing lager beer.

With global annual consumption of well-over 150 billion litres, lager is by far the most popular beer in the world, outselling ales, stouts, and wheat beers.

Based on their research, the team believe that this lager yeast came about as a result of mating of 2 different yeast species - a Bohemian Saccharomyces Cerevisiae and a Bavarian Saccharomyces Eubayanus in the Munich Hofbräuhaus at the start of the 17th century.

Lager yeast is a distinct bottom-fermenting species that prefers cooler temperatures and sediments stronger compared to the top-fermenting ale yeast.

The famous Bavarian Reinheitsgebot brewing ordnance of 1516 stipulated that only bottom fermentation was permitted but in 1548 the powerful nobleman Hans VI von Degenberg was granted a dispensation to allow the brewing wheat beer through top fermentation.

However, when Hans VIII Sigmund von Degenberg, the grandson of Hans VI, died without an heir in 1602, his property and assets - including the family brewery at Schwarzach in Bavaria - were seized by Maximilian I, Duke of Bavaria and later Prince-Elector of the Holy Roman Empire.

Historical records show that on 24 October 1602, top-fermenting yeast were brought from Schwarzach to the Duke’s Hofbräuhaus brewery in Munich, where the brewing of wheat beer then alternated with the traditional Bavarian brown beer.

Now, writing in the peer-reviewed Journal FEMS Yeast Research, the authors propose that by the time a dedicated wheat beer brewery had opened in 1607, top-fermenting wheat beer yeasts from Schwarzach and bottom-fermenting yeasts from the Munich Hofbräühaus had mated to create a brand new species that we now know as S. pastorianus – the lager yeast. And the rest is history.

Prof. John Morrissey of UCC’s School of Microbiology is Director of the SUSFERM Fermentation and Bioprocess Engineering Centre, and co-author of the piece.

“We often think historical events are almost pre-programmed, but this is an amazing example of how chance events – the lack of an heir, the duke’s thirst for wheat beer, and the unorthodox sex between different yeasts, culminated in a new yeast species that changed the world of beer,” Prof Morrissey said.