What makes the world's top beer?

Lager beer lovers always believe that their number one beer is the most special. But perhaps they will have to prepare to drink this statement at the Oktoberfest beer festival in October. The new study, conducted by geneticists from Stanford University School of Medicine, has shown that brewing techniques, the main factor that helps the beer industry grow worldwide, were born thanks to pairing. of two types of yeast, one of which has been used for thousands of years to make beer.

Researchers have brought us a very interesting overview of the early brewing history, and there are also unexpected information about the initial evolution of a new yeast. . Today, brewers are re-using yeast in a few batches of fermented beer, they unknowingly selected the strains that make up the world's best beer.

Geneticist Gavin Sherlock said: 'Ancient brewers have done genetic engineering while not knowing it. They have given us an interesting opportunity to admire a fairly new species but are rapidly changing with the opportunity to enjoy delicious beers' . The study was published online September 11 in Genome Research.

It all started with some people making beer unsatisfied with their results. Not satisfied with the quality of beer brewed in the summer months, they prevented brewing beer when it was warm. However, winter temperatures limit fermentation of yeast, which has been used for hundreds of years. That type of yeast paired differently with a stronger second yeast to create a brewing technique that helped make lager beer today.

Sherlock - assistant professor of genetics - with Dr. Barbara Dunn, research assistant at the medical school, studied the genome sequence of 17 lager yeast lines unique from breweries in Europe and USA. They used DNA microarrays capable of analyzing the relative contribution of parents, combined with a limited DNA sequencing technique to determine the phenomenon of hybridization not only once but twice on reality. This repeated genetic phenomenon shows that each parent has brought specific and different benefits to the pairing process.

Dunn said: 'It is possible that the ale yeast strain brings a certain type of flavor, while the second line increases the fermentation ability at low temperatures. Mixing them together is a way for men to double their genetic ability. '

Lager beer lovers always believe that their number one beer is the most special.But perhaps they will have to prepare to drink this statement at the Oktoberfest beer festival in October.(Photo: iStockphoto / Skip ODonnell)

Usually ale beer tastes like fruit and is cloudy. Although ale beer has more complex flavors than lager beer, ale beer is most consumed when it is warm and less stable. In fact the word 'lager' is derived from a German word meaning 'reserve'. Most yeast reproduce by asexual buds, the daughter cells will separate from the mother cells after the genetic material of the mother cell is duplicated. Sometimes yeast also reproduce sexually and form gametes to pair with another spore of the same species, then clone again. Parental lager yeast lines choose another reproductive path.They choose different species, breed to blend between two species with better adaptability under low temperature conditions.

The couple of larger yeasts are members of a larger family called Saccharomyces. One species of this family, Saccharomyces cerevisiae, commonly known as 'baker's yeast', has been used every year for making bread and ales. S. cerevisiae grows best at temperatures between 85 and 90 degrees F. Another enzyme belonging to this family is S. bayanus that grows strongly at temperatures between 70 and 75 degrees F, they can withstand temperatures. even lower than the above. They combine to form the S. pastorianus strain. Sherlock and Dunn compared S. cerevisiae parents of pastorianus with many other lines, including the line involved in fermentation of wine and sake before identifying it as an ale yeast strain.

Sherlock said: 'We are very excited to discover this connection because it has so many meanings. The same yeast is used to make ales and even larger beer, which makes us even more excited. '

As usual, the descendants of this unusual pairing phenomenon have an unusual amount of genetic material. Sherlock and Dunn believe that a combination of genetic capital from the two types of yeast above is similar, while the other has 2 to 3 times more DNA from S. cerevisiae than S. bayanus. Research on the development of the two types of yeasts will provide a genetic basis for brewing techniques in Europe for over 600 years: a yeast is used in Carlsberg brewing techniques in Denmark and other beers in the Czech Republic - Slovakia; and the other is used in fermentation techniques in the Netherlands, including Heineken beer.

Saccharomyces cerevisiae yeast.(Photo: chateauneuf)

Moreover, it is normal for the descendants of such hybrid processes to gradually lose excess DNA. Finding the lost gene and the time when the hybrids lost their genes at a very young age is a way for researchers to elucidate the evolutionary process as well as find the genes responsible for pleasing the taste of those love beer all over the world.

Sherlock said: 'When we look at lost genes or multiply numbers, we can know some of the genes involved in brewing techniques.' The researchers identified differences in genes involved in sugar metabolism and the process of yeast formation after fermentation.

Why is beer so important in the Middle Ages?

Dunn expressed: ' Beer is the standard drink. Alcoholic beverages at that time were considered beneficial, partly because water was often contaminated. If you drink beer every day, you'll want a beer that tastes great. '

The research was funded by the National Institutes of Health and the National Science Foundation.

Captions (According to Saga.vn):

Beer ale

Ale is any beer that is produced by top fermentation, and it is usually fermented at a higher temperature than lager beer (15-23 ° C, 60-75 ° F). Beer yeasts at these temperatures produce a significant amount of esters, secondary flavorings and other flavoring products, and the resulting beer has the same flavor of flowers or fruits (but not just like that) like apples, pears, pineapples, grass, dry grass, bananas, plums or prunes. Style differences between ale types are greater than lager types, and many ale beers are difficult to classify.

Beer lager

Lager is the most consumed beer in the world. They originated in Central Europe, whose name is the word "lagern" in German. Lager yeast is a type of bottom fermentation, usually fermented at a temperature of 7-12 ° C (45-55 ° F) ("fermentation phase"), and then fermented for long periods at 0-4 ° C (30-40 ° F) ("lager chemical"). In the secondary fermentation period, lager is made in and cooked. Cold conditions also inhibit the natural production of esters and other by-products, creating a "dry and colder" flavor of beer.