One of the questions faced by natural scientists was the Aristotelian doctrine of “spontaneous generation,” or abiogenesis, which propounded that “life” was continually being created out of inanimate matter. The Italian physician Franceso Redi (1626-1679) around 1665, in a fine example of the proper use of the experimental method, placed clean linen cloths over jars containing fresh samples of meat. Flies, attracted to the meat, laid eggs on the cloth. Maggots could later be seen on the cloth, but not on the meat, which proved that maggots grow from eggs and do not develop spontaneously. Unfortunately, Redi failed to convince all of his contemporaries.- - - - - - - - -
Since ancient times, observers had been fascinated with fermentation, which could transform grape juice into wine, but they failed to explain the process. It was the great Frenchman Antoine-Laurent Lavoisier in the 1780s who established the fact that organic compounds consist basically of carbon, hydrogen and oxygen. He did not fully understand the process of fermentation, but his work was a milestone in reaching a scientific understanding of the principles behind it. Another pioneering French chemist, Joseph Louis Gay-Lussac, proposed that fermentation was instigated by the action of oxygen on fermentable material. Huge advances were made during the nineteenth century, aided by improved microscopes.
Some of the best work to disprove spontaneous generation was carried out by the German scholar Theodor Schwann, a pioneer in cell theory in biology and medicine. He allowed air to pass freely over previously heated organic substrates (meat and hay infusions), but only after it had passed through very hot glass tubes. Such infusions failed to yield “life.” In 1837 Schwann demonstrated that alcoholic fermentation was the result of a living organism, not an inanimate chemical mass. He described the morphology of yeast, which he named “sugar fungus,” from which the generic name Saccharomyces emanates. There was nevertheless opposition to the idea of yeast as a living organism from many leading chemists such as the Swede Jöns Jacob Berzelius and the Germans Justus Liebig and Friedrich Wöhler.
The highly influential French scholar Louis Pasteur published work supporting the idea that yeast consists of living cells responsible for fermentation. By the 1870s most authorities had accepted his tenet that “there is no fermentation without life.” This applied not only to alcoholic fermentation, but to the myriad of other fermentations carried out by bacteria. Pasteur did more than any other person to establish acceptance for the germ theory of disease, which makes him a towering figure in the world history of medicine. In addition to pioneering medical advances such as discovering the first effective vaccine for rabies he worked with problems related to the wine industry, which in France is a matter of national pride.
He studied bacteria in the microscope and identified which ones caused a particular wine disease. He demonstrated that these bacteria needed access to oxygen to live and reproduce. The most common is the vinegar bacterium, which is present in all wine and will eventually make it turn to vinegar (Old French for vin aigre, “sour wine”). Vinegar has been used since ancient times in Asian and European cuisines, but it was Pasteur who showed in 1864 that it results from a natural fermentation process.
Emil Christian Hansen (1842-1909), a mycologist and fermentation physiologist from Denmark, was the first brewery scientist to culture and describe brewery yeasts. His work commenced in 1879 after he was appointed to the Carlsberg Laboratories in Copenhagen. A lot of his early work involved the study of diseases affecting beer production, just as Pasteur and others had done for the wine industry. Hansen worked out a method of isolating a single cell from a culture of yeast. In 1883 he had achieved the isolation of the world’s first single-cell culture and introduced pure-culture methods into the Carlsberg brewery. It became known as Saccharomyces carlsbergensis and is used industrially in the production of lager beers.
Lager-brewing seems to have originated in southern Germany, where beer has been made since late medieval times by a bottom-fermentation process where the yeast sinks to the bottom of the brewing vessel; before that, the type of yeast used tended to rise to the top of the fermenting product. Such beers came to be called lager (from German lagern, “to store”). The first lagers in Bavaria were dark brown in color, and the dark version is known as a Munich-style lager. “Lager” refers to yeast that requires a slow fermentation and has nothing to do with color.
The archetypal pale, bottom-fermented lager which most consumers will be familiar with today was first brewed in 1842 in a city called Pilsen, or Plzen, in western Bohemia in what is now the Czech Republic. Local brewers there suffered from stiff competition from imported Bavarian beer but enjoyed some natural advantages; the water in the vicinity was extremely soft with minimal amounts of dissolved solids, which permitted the brewing of very pale, delicately-flavored beers. Bohemia has ancient brewing traditions and grows wonderful hops, whereas neighboring Moravia has plenty of great barley. Bohemians were also fairly well abreast of technological developments. Carl Balling, a professor of chemistry at the Polytechnic Institute in Prague, lectured about the living nature of yeast as early as the 1840s.
Josef Groll (1813-1887), a Bavarian brewer, created the world’s first clear, golden lager beer in Pilsen in 1842. He ended up with an extremely pale drink compared to the dark Munich lagers he knew. As the innovation grew in popularity, the people of Pilsen in 1898 renamed their beloved beer Pilsner Urquell, which means “The pilsner from the original source” in German. This is the original pilsner beer, copied by breweries around the world. Its golden color was a novelty at a time when glass vessels were gradually replacing earthenware vessels.
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