This blog was created after an interview with Vinicius Avellar Werneck, Beer Sommelier from Brazilian Institute of Beer; Graduated in Beer Technology from Brau Akademie; and Brewmaster of Werneck Brewery.
Since 2016, the Werneck Brewery has been dedicated to producing beer using artisanal methods and natural inputs. Since inception, the Werneck Brewery has been awarded two gold medals: Best beer in the Carnaipa contest in Rio de Janeiro 2018 (Session IPA), and best beer in the Brazilian National Contest Brau Akademie 2018 (Werneck Gold – Belgian Golden Strong Ale).
The intent of this blog is to present basic information regarding beer and CO2.
Beer is food. In fact, it was an important part of the diet of early humans. Real beer is full of vitamins, minerals, protein, and antioxidants. Most anthropologists now believe that societies gave up the hunter-gatherer lifestyle and settled down to pursue agriculture in order to grow enough grain to make beer. The discovery of beer was a happy accident somewhere in Africa more than 10,000 years ago. Someone used damp, sprouted grain to make porridge, and when the porridge was heated, it became sweet. (OLIVER, 2005)
In those earlier times, all the gas was released in the production process. This kind of barley soup did not have gas inside. It was flat. In fact, originally this soup was used as nourishment, not as a beverage. Over in the years, with new technologies, the CO2 in the beer became pressurised and the production process became more accurate.
Essentially, to make beer, the barley is cooked to release sugar that will be consumed by the yeast in fermentation. The yeast will transform the sugar into two elements: alcohol and CO2. During this process, the CO2 is release via an airlock valve leaving only alcohol in the beer.
The yeast activity is one way to add gas inside the beer. Before bottling the beer, the brewer adds a sugar-based solution inside the beer. The remaining yeast will consume this sugar and, with the bottle closed, the gas will be retained with the beer. This is the natural way to put gas inside the beer, known as priming.
Another method, faster and more efficient, and normally used in big breweries – it is better for high production – is also accessible for home brewers. This alternate method, called forced carbonation, is to add the CO2 into the beer. The CO2 is added to the beer using a cylinder of compressed gas. Pressure gauges, hoses, connectors, and regulators are required when putting CO2 into the beer when using pressurised cylinders. In this way the brewer has more control over the volume of CO2 inside the beer and the beer is ready to be consumed in approximately two days.
Temperature has a key role in forced carbonation. There is a forced carbonation chart that shows the correct pressure each beer style needs in a specific temperature to reach a specific CO2 volume in the beer – see chart below.
When the beer is carbonated it tastes different. The gas gives a refreshing sensation for the beer. The carbonation is also responsible for the bubbles that create the foam which is important to retaining the beers temperature. The volume of CO2 inside the beer is related to the foam consistency. Different beer styles have distinct volumes of CO2 required. The average CO2 volume is between 2.2 and 2.6. Some styles can be flatter, like English Ale, and others more carbonated, like the Weiss.
https://www.kegerators.com/carbonation-table/ access: 12/10/20 at 1:33pm
https://chme.nmsu.edu/files/2016/06/Brite-tank-carbonation.pdf access: 10/10/20 at 11:25am
The Brewmaster’s Table : Discovering the Pleasures of Real Beer with Real Food. By Garret Oliver ECCO Press,U.S. / April 2005