Continuous production of beer mixed beverages at Stieglbrauerei

Stieglbrauerei in Salzburg is one of Austria’s largest and leading private breweries. Besides its leading beer brand Stiegl the share of beer mixed beverages in the product range is steadily increasing. These beverages include the "Stiegl Radler" (a mixture of beer and lemonade) in the flavours raspberry, lemon and unfiltered grapefruit as well as the elderberry wheat beer mix "Stiegl-Weisse Holunder-Radler".

In summer 2011, the brewery was looking for a technology for the flexible and efficient production of high-quality beer mixed beverages. This technology should replace the existing batch production process with a low level of automation.The decisive factor for Stieglbrauerei to entrust GEA Brewery Systems with this project was the convincing customized plant concept designed for complete automation of the core processes dosing and blending, optimum adaptation to the space available in the brewery and minimization of product losses.

The blending system is designed for a nominal capacity of 300 hl/h. It produces finished carbonated beverages by direct inline dosing and blending of the beverage components

• beer;

• deaerated, cooled brewing water supplied from a central holding tank;

• beverage base supplied from four stationary storage tanks or from flexible intermediate bulk containers;

• carbon dioxide

into the finished beverage pipe according to the recipes stored in the process control system.

The use of precision flow meters – mass flow meters are used in the dosing lines for beverage base and carbon dioxide – and special digital flow controllers ensures a very high degree of blending accuracy.

A subsequent 50 hl buffer tank hydraulically separates the blending system from the filling lines. During the production process, the control system automatically and continuously adjusts the blending system capacity to the withdrawal capacity of the filling line down to 50 % of the nominal capacity. Thus, the number of system shutdowns is minimized and a consistently high blending accuracy is achieved.

During production, already at the inlet of the buffer tank, precise analytical devices, especially designed for measurements in beer mixed beverages, continuously record the quality parameters original gravity in °Plato, alcohol content in vol % and CO₂ content in g/l.

The information is transferred via a data bus system to the process control system.

Ensuring maximum efficiency

After pre-selection of the desired quantity of finished beverage to be produced and after connection of the respective beverage base source – storage tank or flexible intermediate bulk container – the blending system is started fully automatically, produces the preselected quantity and is automatically shut down again when this quantity is reached.

During shutdown of the blending system, the dosing lines for beer and beverage base are pushed out with deaerated water, so that product losses are minimized. For this purpose, the beverage base line is installed along the stationary storage tanks and the location for the flexible intermediate bulk containers with a gradient to the dosing pump at the blending system.

The blending system and the buffer tank fit harmoniously into the brewery. A compact design was particularly important for the customized system, so that the two functional units that were already completely pre-mounted in our workshop in Kitzingen require as little floor space as possible.