Lager, Ale and Yeast
German Beer, Oktoberfest & the Reinheitsgebot
Course 1 · Chapter 4 · Lager, Ale and Yeast
The pale golden lager that most of the world now thinks of as beer is, in historical terms, a fairly recent arrival. For most of brewing history, beer was an ale, made with yeast that works warm and fast. Lager came from a particular habit of Bavarian brewers, was transformed by nineteenth-century science and engineering, and then spread across the world faster than any other style. This chapter explains the difference between the two families, the Bavarian cellars where lager took shape, the inventors and scientists who turned it into an industry, and the fact that the whole story happened without anyone understanding what yeast was. Dates and names are given from general knowledge and flagged where they should be checked.
Two Families of Beer
All beer depends on yeast, but there are two main groups of brewing yeast, and they behave differently.
| Ale (top-fermenting) | Lager (bottom-fermenting) | |
|---|---|---|
| Temperature | Warmer, roughly 15 to 24 degrees Celsius (check) | Cooler, roughly 7 to 13 degrees Celsius (check) |
| Where the yeast works | Gathers at the top of the vessel as a foam | Settles toward the bottom |
| Speed | Fast, a matter of days | Slower, followed by weeks of cold storage |
| Typical character | Fruity, rounder, more varied flavours | Cleaner, crisper, more restrained |
| German examples | Weizen, Kölsch, Altbier | Pils, Helles, Märzen, Bock |
Bavaria and the Cold Cellar
Bavarian brewers noticed that beer made and stored cold turned out clearer and kept longer. A Bavarian ordinance of 1553 is often cited as banning brewing in the summer months, between roughly late April and late September, because of the danger of fires and spoiled beer (check the year, the dates and the reasons). The result was that brewers made a strong beer in spring and kept it through the summer in cold cellars and caves cut into the hillsides, a practice called lagering, from the German word lagern, to store. In the cellars, the yeast that settled and survived the cold was bottom-fermenting yeast, selected without anyone planning it.
- Ice. Brewers cut ice from lakes and rivers in winter and packed it in the cellars to keep them cold.
- Trees. Chestnut trees were planted over beer cellars to shade them, a habit that is the origin of many Bavarian beer gardens (check; see Chapter 6).
- Märzen. The last beer of the season, brewed in March, was strong and stored for the summer, and it gave a style its name (check; see Chapter 5).
The Nineteenth-Century Breakthroughs
Until about 1800, lager was mainly a Bavarian local habit. In the nineteenth century, a run of advances in engineering, science and travel changed that.
Copying the best
Gabriel Sedlmayr of Munich's Spaten brewery and Anton Dreher of Vienna are credited with improving lager brewing in the 1830s and 1840s, including by travelling to British breweries to study methods (check the dates and the claims). Both are linked to new amber and dark lagers.
Pilsner
In 1842, the town of Pilsen in Bohemia, now in the Czech Republic, produced a pale, clear, hoppy lager made by a Bavarian brewer, Josef Groll (check the date and the details). Together with new pale malt and the clear glass that was becoming cheap, it set the style that conquered the world. Pilsner is Czech in origin, though it is now a major German style.
Refrigeration
In the 1870s, the German engineer Carl von Linde developed a practical refrigeration machine, first used in a Munich brewery (check the date and the first user). Brewers no longer needed natural ice or caves, so lager could be made all year, anywhere.
Yeast science
Louis Pasteur, the French chemist, showed in the 1860s and 1870s that fermentation was done by living yeast, and wrote a book on beer in 1876 (check the dates and title). In the 1880s, Emil Christian Hansen, working at the Carlsberg brewery in Copenhagen, isolated a single yeast cell and grew pure cultures, so that each brewery could use a reliable strain (check the date).
Lager Conquers the World
With cheap rail transport, refrigeration, glass bottles and pasteurisation, lager could be made on an industrial scale and shipped far from the brewery. It spread in several ways (check the details of each).
- Emigration. German brewers who emigrated to the United States in the nineteenth century set up large lager breweries, and several of the best-known American brands were founded by Germans.
- Empire and trade. Lager breweries appeared in Asia, Africa and South America, often founded by German or Danish brewers.
- Competition with ale. In Britain and Ireland, ale and stout held on for a long time, and lager became widely popular only in the later twentieth century. Scotland followed the same pattern, with lager breweries established in the later nineteenth century and growing in importance after the Second World War (check the dates).
Lager's success also had a cost. Mass-produced pale lager, brewed for cost and consistency, pushed many local beers out of the market, a trend that the craft revival of Chapter 10 reacts against.
Exercises
Compare ale and lager in a short table or list: temperature, where the yeast works, speed and typical character. Give one German example of each.
Explain how the Bavarian summer brewing ban and the cold cellars helped to create lager, even though nobody understood yeast at the time.
Name three nineteenth-century developments that helped lager spread across the world, and say what each made possible.
Quick Reference
- Ale: top-fermenting, warm, fast, fruity
- Lager: bottom-fermenting, cool, slow, with cold storage; a hybrid yeast
- 1553: Bavarian summer brewing ban, leading to cellars and lagering (check)
- 1842: Pilsner first brewed in Pilsen (check)
- 1870s: Linde's refrigeration machine (check)
- 1876 and 1880s: Pasteur on beer; Hansen's pure yeast cultures (check)
- Spread: rail, glass, refrigeration and emigrant brewers
Next chapter: A Map of German Beer Styles, which tours the styles of the regions and the rivalries between them.