Origins of yeast used to make lager traced to Tibetan forest, scientists say
Scientists claim to have discovered the "Eve" of lager yeast in the mountain forests of Tibet, a finding that could be used to give Chinese beer a flavour different from its European rivals.
Microbiologists have for decades hunted for the ancestor to Saccharomyces bayanus, a yeast species widely thought to be one of two parents of S. pastorianu, used for hundreds of years to make lager. The yeast was active in low temperatures, so most searches were conducted in cold, mountainous areas.
In 2011, an international team found a candidate in Patagonia in Argentina, but the suggestion it was the original ancestor was met with arguments over whether the yeast had travelled from Europe over the Atlantic Ocean.
But a team from the State Key Laboratory of Mycology at the Chinese Academy of Sciences (CAS) believes it has finally found the "Eve" of S. bayanus.
According to Han Peijie, a researcher with the laboratory, genetic studies on wild yeasts his team collected in the deep forest of Tibet's Nyingchi prefecture strongly suggested Tibet was the birthplace.
"Tibet may be harsh to human beings - it is very cold with thin air. But to beer yeasts it can be heaven. We found them everywhere, from the bark of trees to the soil underneath," he said.
"To us this is an utterly surprising discovery. We have collected samples in more than a dozen provinces in China, but the richness of micro-organisms in Tibet has exceeded our wildest expectations."
Lager originated in Bavaria, Germany, during the 15th century. The researchers said the Tibetan yeast might have reached European countries via the Silk Road more than 2,000 years ago.
"China had a chance to discover and exploit beer yeast more than any other country, but there is no trace of beer in its history," Han said. "Maybe it's a cultural thing. Maybe our ancestors did not like the taste."
That is not the case now. Beer consumption in China hit 50 billion litres in 2012, making it the largest market. Yeasts used by Chinese brewers came from Europe and the United States, which gave Chinese beers a similar, some may say inferior, taste to their Western competitors.
The discovery in Tibet could change the situation, Han said.
Beijing Yanjing Brewery, one of the largest brewing companies in China, is in cooperation with the CAS team to domesticate the wild beer yeasts from Tibet and produce beverages with a fresh taste.
Han estimated the process would take a year or two.
"The Chinese brewing industry has invested a lot more money on marketing than scientific research. Now some of them realise that without fundamental, cutting-edge research on microbiology, they will not make a splash in the international market."