The Chemistry Of Beer: How It Works And Why It Matters

In the Stuff You Should Know episode 'How Beer Works', Josh and Chuck embark on a journey through the history of beer, its production process, and the science behind it. The episode covers the evolution of beer from ancient times to the present, including the role of beer in the development of civilisation, the impact of historical events such as Prohibition and World War II on beer production and consumption, and the resurgence of craft breweries in recent years. The hosts also delve into the basic ingredients and the biochemical reactions that transform these ingredients into the beverage we know as beer.

The history of beer

Beer is one of the oldest human-produced drinks, with the earliest archaeological evidence of beer-like substances dating back 13,000 years, to residues of a gruel-like beer used for ritual feasting in what is now Israel. The earliest chemical evidence of barley beer was discovered in Iran and dates to between 5,400 and 5,000 years ago.

The written history of ancient Egypt and Mesopotamia records the use of beer, and the drink has spread throughout the world. A 3,900-year-old Sumerian poem honouring Ninkasi, the patron goddess of brewing, contains the oldest surviving beer recipe, describing the production of beer from barley bread. In China, residue on pottery dating from around 5,000 years ago shows that beer was brewed using barley and other grains.

Beer may have been known in Neolithic Europe as far back as 5,000 years ago, and was mainly brewed on a domestic scale. Beer was also produced and sold by European monasteries as early as the 7th century CE. During the Industrial Revolution, the production of beer moved from artisanal manufacture to industrial manufacture, and domestic manufacture ceased to be significant by the end of the 19th century. The development of hydrometers and thermometers changed brewing by allowing the brewer more control of the process, and giving greater knowledge of the brewing product.

Today, the brewing industry is a global business, consisting of several dominant multinational companies and many thousands of smaller producers ranging from brewpubs to regional breweries.

How beer is made

Beer is made from four simple ingredients: barley, water, hops and yeast. However, it's not as simple as mixing these ingredients together. A complex series of biochemical reactions must take place to convert barley to fermentable sugars, and to allow yeast to live and multiply, converting those sugars to alcohol.

Firstly, malted barley or malted grain is dried, cracked and heated so that the sugars start to come out. This is then steeped in a tank of water to create a substance called 'wort'. Hops are then added to the wort, which is boiled for about an hour. The type and amount of hops added will depend on the kind of beer being made. For example, Budweiser has eight to ten IBUs (International Bitterness Units), while a stout will have thirty to fifty.

The wort is then put in a tank with yeast to start the fermentation process. The type of yeast used will determine how long this process takes. For an ale, tough fermenting yeast is used at room temperature, and the beer will be ready to drink in a few weeks. For a lager, the beer is stored at near-frozen temperatures and the fermentation takes place at the bottom of the tank. This process takes a few months.

Finally, the beer is carbonated. Traditionalist brewers may use bottle conditioning, where the yeast carbonates the beer naturally.

Beer and the development of civilisation

Beer is one of the oldest human-produced drinks, with the earliest archaeological evidence of beer-making dating back to around 5,000 years ago. It is believed that the development of beer may have played a significant role in the development of civilisation.

The advent of agriculture began in the Neolithic Period of the Stone Age about 11,500 years ago. During this time, once-nomadic groups settled down and came into contact with each other, leading to the establishment of more complex social customs and communities.

One theory suggests that the domestication of cereals was not primarily for food, but for the production of beer. This theory is supported by archaeological evidence indicating that people went to great lengths to obtain grains, despite the hard work needed to make them edible. Additionally, the importance of feasts as community-building gatherings further supports the idea that cereal grains were being turned into beer.

Beer played a significant role in these feasts, which held vital social significance. Feasts were essential for creating debts, factions, bonds, political power, and support networks—all crucial elements for developing more complex societies. Beer, with its ability to alter attitudes and suppress social codes, facilitated these social interactions.

The written history of ancient Egypt and Mesopotamia records the use of beer, and a 3,900-year-old Sumerian poem honouring Ninkasi, the patron goddess of brewing, contains the oldest surviving beer recipe. Beer was also mentioned in the Epic of Gilgamesh, where the 'wild man' Enkidu is offered beer, which he drinks until his "heart grew light [and] his face glowed".

Beer was also an important part of daily life in ancient civilisations. For example, during the construction of the Great Pyramids in Giza, each worker received a daily ration of four to five litres of beer, serving as both nutrition and refreshment.

The production and consumption of beer continued to play a significant role in societies throughout history, with brewing techniques and technologies evolving over time. During the Industrial Revolution, beer production shifted from artisanal to industrial manufacture, and innovations such as the hydrometer and thermometer revolutionised the brewing process, giving brewers more control and knowledge.

Today, the brewing industry is a global business, with a projected growth of $148.43 billion between 2024 and 2028. While the process of beer discovery and its specific role in the development of civilisation remain a subject of debate, its impact on human history and culture is undeniable.

Beer in the Middle Ages

The quality of beer improved around the year 1200 when brewers in Bremen, Germany, discovered the exact amount and type of hops to add to the beer so that it could be stored for up to six months. This advancement in brewing allowed beer to be shipped to other regions, such as England and the Low Countries, contributing to its growing popularity across Europe.

During the Middle Ages, beer was typically named based on its color, heaviness, price, and other factors. For example, the Belgian Pharaoh beer had no connection to Egypt, and Convent beer was not necessarily brewed in a monastery. The taste and quality of beer varied significantly from one batch to another, even when brewed by the same brewery, due to the lack of control over yeast and the different standards of sanitation.

The use of "gruit," a combination of botanicals that provided flavor and prevented bacterial growth, was common in early and central European beer-making during the Middle Ages. However, by the 12th century, brewing with hops became more prevalent, especially in Northern Europe. Hops required less grain, resulting in cheaper production costs, and beers made with hops tended to have a longer shelf life due to their resistance to bacterial infection.

In the 15th century, Bavaria passed laws mandating that beer could only be made with barley, water, yeast, and hops. These laws were implemented to simplify taxation rather than for safety or taste reasons.

Beer in the US

Beer has been around in the US since before it was the US. In 1609, the first ads appeared in London newspapers asking for brewers to move to the Virginia colony. In 1612, the first brewery was set up in New Amsterdam by Adrian Block and Hans Christian Anderson.

In the US, beer was initially made with corn, which made for a terrible beer. In 1756, Arthur Guinness signed a 9,000-year lease on a building in Dublin, where he made the famous Guinness beer. In 1773, the US hit its peak number of breweries: 4,131 breweries supplying a population of just 50 million people.

In the 1940s, men went off to war and women became the market for brewers, preferring a lighter style of beer. For almost three decades after World War II, the only beer widely available in the US was a light lager. In 1976, the first craft brewery, New Albion Brewery in Sonoma, California, opened and inspired hundreds of others to take up craft brewing.

In 1980, there were eight craft breweries in the US; in 1994, there were 537; and in 2010, there were over 1,600. As of 2011, there were over 1,900 breweries in the US, the highest number since the 1870s.

Some notable US breweries include:

• Arizona Beer House, a family-owned and operated craft beer and wine bar in Tucson, Arizona, with 35 taps featuring Arizona and regional beers.
• Barrio Brewing Co., Arizona's first 100% employee-owned brewery, established in 1991.
• New Albion Brewery, the first craft brewery in the US, which opened in 1976 in Sonoma, California.

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