Well, isn’t it amazing: A 30-litre keg holds 63 pints of liquid happiness – and we call it beer! It looks like an ordinary beer keg, but revolutionized the industry, opened market borders for the heady drink, allowing it to travel, conquer countries and continents, keeping its properties for a long time.
What is a keg?
Firstly, let’s look at the terminology. A keg (from kagg – “keg”) is a cylindrical container of metal or plastic used to store, transport and serve beer under pressure.
The history of the keg
The grandfather of the keg was the clay pitcher, and the mother of the keg was the wooden barrel, serving brewers for centuries. The keg was the place where beer was sent for fermentation. The beer was served directly or with a pump. Either way, oxygen entered the cask, which quickly oxidised the beverage. Therefore cask ales had to be sold within a few days. If beer historians are to be believed, the first metal kegs appeared in 1929 thanks to the German company Krupp. The term keg, on the other hand, didn’t catch on until the early 1950s. At the initial stage, metal kegs had no spectacular technological attachments. However, the sturdy, durable kegs were gradually replacing wooden barrels in breweries and pubs, which were increasingly used as ageing containers. In the mid-twentieth century, following a series of improvements, kegs acquired a socket and a valve fitting – a clever device (although it looks like a simple tube with a head), thanks to which the container is washed, beer is poured and the drink is served to the filling tap. The fitting seals the keg and prevents oxygen from getting into the keg, and it also makes it easier to maintain microbiological cleanliness in the container. All this helped to improve the quality of beer in transit, to increase the shelf life of the beverage, to open new export routes and to raise brewing to a new level of evolution. By the way, kegs are also used for storage/transportation/pouring of kvass, wine and other alcoholic and non-alcoholic beverages.
The working principle of a modern keg is that beer is dispensed from the keg by means of carbon dioxide. Kegs and CO2 bottle are connected by a special coupling sleeve, which is pushed onto the keg fitting. This design forces the gas into the keg and pushes the beer into the fitting’s tube, pushing it onto the tap.
Kegs are different…
The best-known keg manufacturers in Europe are Thilmann, Schafer, Blefa GmbH, Comet. Popular keg volumes are 20, 30 and 50 litres. DIN and EURO-formats are commonly used, and the FINN and PLUS standards are also used. Kegs are made of metal (stainless steel), metal with polyurethane coating, plastic.
Durability of beer kegs
Metal beer kegs are a reusable container. Containers are practically unformed during transportation, easy to clean and repair, failed fittings can be quickly replaced. With the observance of the rules of exploitation and careful use a keg serves 25-30 years. A plastic keg is designed for one use.
Keg safety zone
Most keg manufacturers today install a special “anti-explosion” mechanism, called a “safety point” in the container. If the keg pressure rises above a critical level, the safety point will rupture. But the keg itself won’t go through a big bada-boom.