The making of modern beer

Long before lager came to dominate the mass market, its brewers revolutionised the industry, writes Mark Dredge


The awesome scale of global lager makes it so ubiquitous that we’re often blind to it or defiantly against it. Yet whether you’re anti, ambivalent or all-for opening a cold mainstream lager, most drinkers are unaware of the industry-changing developments which were pioneered by lager brewers towards the end of the 19th century, where a succession of scientific, technological and industrial advances took brewing from a local empirical craft into the modern international industry that we’re familiar with today. 

In the early 1800s, European brewing (with the exception of Britain) was small-scale and regionally idiosyncratic: most Belgian brews were low alcohol, sour wheat beer; Hamburg’s brewers made sweetish wheat and barley ale which had to be drunk fresh before it soured; and Bavarians brewed with barley and a special ‘lower fermenting’ yeast which they stored, or lagered, in cold underground cellars. 

Bavarian beers had been brewed that way since the early 1400s and little had changed by the beginning of the 1800s. Brewing only took place from the end of September through to the end of April. Beers were brewed aboveground then went underground to ferment and mature, and they tasted dark and smoky thanks to the old malting techniques. Brewing was local, hands on and hard work, with extremes of hot and cold, and it relied on passed-down processes instead of scientific knowledge and instrumentation. It would take until the 1830s for Bavarian brewing to begin to grow and change, but before lager breweries could get bigger, they had to get better. To get better, they had to get smarter. To get smarter, they had to learn from the industrialised British ale brewers who were decades ahead of European brewers. 

Numerous brewing books now detailed different techniques and processes, and how and why to use new scientific instruments. The books wrote about how to make pale, smoke-free malt with indirect heat. The sugars extracted from those paler malts were being measured with hydrometers. Brewers were using thermometers and aiming for specific temperatures at each stage of their many processes. Microscopes let them look closer at their beer (even if they didn’t really know what they were looking at yet). 

When pioneering Bavarian and Austro-Hungarian brewers began to read the brewing texts and use the new tools, techniques and teachings, they developed theoretical brewing processes and applied them to their old practices. They began to understand the temperatures which were important to them; they used the British malting methods to produce smoke-free lagers; and the beers got more consistent. Once they had more control over their processes, brewers could start to scale up, and they did this by introducing steam.

Steam powered many parts of the brewing operation – from milling malt to heating mash tuns to lifting barrels of beer – and this allowed everything to be done in incrementally greater volumes. Making more beer required more underground cellars, and brewers needed to find new ways of maintaining cold temperatures as the cellars filled up.

Go a storey or two below ground and it’s a reliable 8-12ºC, which is the ideal temperature for lager fermentation. Lager fermented for two weeks in open-topped wooden vessels before being transferred into large (up to 4,000 litre) sealed barrels and rolled deeper into the cellars where it was colder. As steam was helping to heat things aboveground, now ice was needed to keep things cool below ground, and brewers would harvest natural ice in the winter – this is one reason lager brewing was localised to cold climates until artificial refrigeration was possible at the end of the 19th century. 

By the 1840s, steam, ice, science and industry had combined to move lager brewing into a new formalised age, and the developments created distinctive styles of lager, with the first three main types being brown Bavarian lager, amber Vienna lager, and golden Bohemian Pilsner. Lagers started to travel and one of the first places to brew lager outside of Bavaria and surrounding regions, was North America. It’s there that many significant brewing advances took place. 

There was a mass migration of German citizens through the middle of the 19th century and many of them settled in North America, where they created new cultures based on what they knew from home, and beer was an important part of that. There had been beer in North America since long before the Germans arrived and it was mostly British-style ales, but it wasn’t particularly popular and Americans preferred whiskey. Within a generation that totally changed and Americans became beer drinkers – they became lager drinkers. 

The early American-brewed lagers were made by Germans and mostly drunk by them. The beers were malty-sweet, dark in colour, around 3% ABV, made to the Bavarian brewing seasons and cold-stored in ice-filled cellars. 

Early Americanbrewed lagers were made by Germans and mostly drunk by them

Through the 1850s and 1860s, over 2,000 lager breweries opened in North America, many of them in cities with large German populations and temperate weather like Chicago, Milwaukee, Cincinnati and St Louis. Almost all beer was drunk in local taverns, served directly from wooden barrels, and beer didn’t travel far. Yet some of the more ambitious brewers weren’t satisfied with just being a small local producer and they saw opportunities to sell beer in towns where there was no local lager brewer, and this mindset marked the beginning of perpetual growth which would come to define the American beer industry. From the 1870s through the 1890s, German-American brewers overcame numerous challenges, made many great advances, and quickly adopted new technology to change the future of brewing.

The first great challenge was how to get the beer into new markets, and two separate industries had to be readied for this to be possible: railway networks and large-scale bottling.

The expansion of the railways opened up the country and created the possibility for brewers to reach new areas, potentially hundreds or thousands of miles away, and in places like the south where the weather made it challenging to brew good lager. But sending railcars filled with heavy wooden barrels was impractical. Brewers needed to ship bottled beer. 

Beer had been bottled for a few hundred years but it was a laboriously manual process. Brewers took inspiration from the expanding soda industry, but before they could do anything they had to redesign the actual bottles to withstand the pressures of travel and carbonation. The first bottles had cork closures, then they were flip-top, with the crown cap used from 1892. Brewers gradually built huge bottling halls using assembly lines (which they did years before the motor industry) and employed hundreds of people, while independent bottling plants were set up all around the country. 

By the mid-1870s, the beer in the bottles and barrels was evolving, with brewers using increasing percentages of maize or rice in their recipes to produce lighter tasting and lighter looking beers which appealed to the American consumer. There was still one major problem with lager: it was susceptible to souring and bad beer could afflict any brewery at any time. To ensure beer always tasted good brewers needed to properly understand and control their yeast. 

The deliberate process of fermentation had been taking place for millennia but it wasn’t until 1857 that Frenchman Louis Pasteur figured out that yeast was a living microorganism which converted sugars into alcohol and carbon dioxide. A few years later, while trying to understand why some wine soured, Pasteur announced that bacteria were responsible for the sourness and he discovered that heating bottles of wine killed any bacteria within it. He hadn’t even done experiments on beer before American breweries started using his pasteurisation technique.

Pasteur hadn't even done experiments on beer before American breweries started using his technique

What Pasteur didn’t realise was that it wasn’t just bacteria which could make a beer taste bad, and wild yeast, like brettanomyces, could also infect a beer. In 1883, a bad case of the ‘beer sickness’ at the Carlsberg brewery in Copenhagen led their laboratory director Emil Christian Hansen to isolate single cells of healthy yeast and propagate them into batches big enough to brew with, and with this came a new control over consistent fermentation.

Pasteurisers and propagation tanks soon became essential for the lager brewers who bottled their beers, and together they enabled better, more reliable, and more stable beer. Another way to help keep beer stable is to keep it cold, and that became the next challenge. 

Natural ice was still fundamentally important to keep lager cellars cold in the early 1870s. As steam-power enabled growth in the outputs of breweries, cellar capacities had to grow, meaning more ice was essential. Mechanical ice production was possible from the mid-1870s and it was introduced into Bavaria and then spread to North America, with great machines producing endless blocks of ice which breweries loaded into their cellars, and also onto refrigerated railcars which transported their beers around the country. The extra temperature control of man-made ice meant that lager brewing could now take place year-round, but that meant brewing more beer, which necessitated even larger cellars, and even more ice…  

Artificial refrigeration was the next great industrial development and the first lager breweries went ‘ice free’ in the 1880s, building massive mechanical refrigeration plants to cool the air in their cellars, a bit like large air-conditioning units. This was significant: by reliably controlling the temperature of where beer was fermented and stored, lager could come up from the limited space of underground cellars and into potentially huge aboveground storehouses. When this could happen, lager could be brewed anywhere in the world, and not just in cool climates. 

Brewing tanks also changed around this time, allowing even larger tanks which were easier to clean and maintain than wood, using materials like enamel, glass-lined vessels, concrete, then later mild steel. Crucially some of these vessels could now be air-tight and pressurised and that combined with desire for more efficiency, where two more developments pioneered in North America would have a significant impact: filtration and forced carbonation. 

Clarity became a key visual cue to a lager’s quality, especially with bottled beer, and drinkers started to demand a sparkling bright glass of beer that was free of yeast sediment. If you leave a lager to mature for several months, the yeast naturally settles to leave a clearer drink, but brewers now needed clear beer in weeks, not months. Some brewers started to use woodchips in their tanks which was an effective way of drawing the yeast out of suspension, but a mechanical filter was more effective and allowed younger beer to be passed through it cloudy and come out clear on the other side. 

Clarity became a key visual cue to a lager's quality

This bright beer could then be force-carbonated. The old way of carbonating a lager involved moving it from its large maturation barrel into a smaller serving cask, adding a ‘krausen’ of fresh fermenting beer (including the yeast), bashing a bung into the barrel, and a secondary fermentation created carbonation. The same thing happened in bottles: flat beer plus fermenting beer put in a sealed bottle created bubbles, but that left yeast sediment in the bottles.

Brewers worked out how to capture the carbon dioxide from fermentation and use it to force-carbonate a filtered beer inside a pressurised tank, before it was bottled and then pasteurised. Then one final thing was needed to make lager truly modern: a label printed with the beer’s brand name. 

Every established industry changed in the 19th century. For brewing it saw in a new era of beer production with brewers now understanding their beers on a microscopic level which helped them to produce mighty volumes of beer. Year-round, mass-production was finally possible, pioneered by the great lager brewers of central Europe and North America. As brewing began to spread around the world, new breweries were built specifically to make pale, clear, carbonated, refreshing and reliable lager. 

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