Until the Middle Ages, magical herbs and cult objects were laid around the wort copper to prevent the brewing process going wrong. The last so-called brew witch was burnt at the stake in Germany in 1591. She was made responsible for the brewer’s beer going bad.
The types of beer that could be brewed depended on the season. Bottom fermented beer was brewed in winter, top fermented in the summer months. The Purity Law still did not allow for yeast. That came from the air, for which reason bakers were often favoured when brewing rights were granted.
Today we know better. In addition to the Purity Law, which prescribes the ingredients, the “Cleanliness Law” must also be strictly adhered to.
Brewing takes place in batches in containers that hold up to 500,000 litres. So that nothing can go wrong and the consumer always gets his preferred beer type with the same taste, the temperature must be precisely controlled in all steps of the manufacturing process.
It is here that we encounter the rotary joint machine element. Mighty stirring arms, through which cooling water flows, gently stir the mash and ensure an exact temperature, which must always be constant and the same for every batch. The stationary pipeline is connected to the rotating arm by a rotary joint.
Rotary joints are not only used in the final brewing process – rotary joints or swivel joints are also used in the manufacturing of the ingredients. The airborne yeast of the mediaeval bakery has long been replaced by precisely bred brewer’s yeast, which is continually turned into yeast powder in drum dryers with the help of rotary joints. This is then fed into the fermentation tank in a precise quantity and purity.
Hop cones in their original form are added to the copper nowadays in palletised form. The desiccated hops are ground and pressed into pellets. Rotary joints can prevent the overheating of the grinding and pelletising rollers here.
Compliance with the “Cleanliness Law” is indispensable in brewing technology. All materials of the containers and fittings used must therefore comply with this law. The rotary joints and swivel joints from HAAG + ZEISSLER are therefore offered in stainless steel. Electropolished versions are available if desired for reducing wettability, in addition to which versions can be supplied with food-safe flanges or dairy fittings according to DIN 11851.