'Jupiler beer is a crystal clear pilsener, yellow straw in colour and bearing a fine white lace. Its slightly grassy nose evokes aged Saaz hops - very mellow and distinct with a touch of pale malt. An exceptionally light, crisp and smooth palate with an infinitesimal degree of maltiness and a dry aftertaste.'
With the sophistication of the beer market now beginning to rival that of the wine market, consumers are becoming increasingly attuned to the individual character of different beers and expect each and every batch of their favourite brew to be 100% consistent in its appearance, odour, colour and taste. This in turn demands 100% consistency not just in the quality and characteristics of the raw materials, but in the parameters of the brewing process itself.
Quality control in breweries has traditionally been achieved through laboratory analysis of samples taken at key stages, and the opinion and advice of a panel of experienced tasters. To optimise the quality and thus the competitiveness of their products, modern breweries now also utilise advanced technologies that include automated computer-driven brewing systems and in-line instrumentation.
At Interbrew Jupille in Belgium - the brewers of the Jupiler beer described above - the brewing process is automatically and continuously evaluated and verified. The brewing engineers are constantly working to improve quality management and can intervene in the production process at any stage.
As an example, as well as filtering and CO2 saturation management, the filtration process at the Interbrew Jupille brewery involves the precise dosing by weight of ingredients that improve the beer quality. This includes the addition of isomerised hops extract injected at < 2 kg/hour by a frequency-driven volumetric pump. Although the frequency can be adjusted to alter the pump speed, the pumps measuring accuracy was not sufficient. To guarantee that the end product always conforms to the set standard, the dosing is not measured by the pump but rather by an accurate in-line flowmeter and the pump frequency is adjusted according to the measured output of the flowmeter. This achieves a closed-loop control circuit with a permanent precision-control and post-control function.
For this application Interbrew selected Endress+Hauser's Promass 83 A Coriolis mass flowmeter, on the basis of its well-proven precision and cleaning in place (CIP) advantages. For small flow rates Promass 83A is available in three models: with a 1 mm diameter tube for measuring ≤ 20 kg/hour; with a 2 mm diameter tube for measuring ≤ 100 kg/hour; and with a 4 mm diameter tube for measuring ≤ 450 kg/hour. In spite of the very low dosing rate required, Interbrew chose the 4 mm model to cope with the exceptionally high viscosity of the hops extract. The 4?20 mA output signal from the Promass 83 A is at the analogue input of the PID controller, which in turn adjusts drive frequency to the central point.
The usage of the hops extract is not controlled by a series of flowmeters but rather, an Endress+Hauser capacitance level sensor is used to measure the level in the buffer vat - on the basis of which consumption is continuously controlled in the programmable logic controller (PLC) and compared against the mass flowmeter.
As demonstrated by ongoing laboratory testing of samples, the quality of the product has significantly improved since the mass flowmeter was added to the control loop. This finding is enthusiastically endorsed by Interbrew's group of experienced tasters, who remain dedicated to investigating the quality of each and every vessel of Jupiler beer before its final filtration.
Endress+Hause''s user-friendly Applicator Selection software tool at www.au.endress.com can help customers explore their Coriolis mass flow measurement options and determine exactly which Promass model they need.
For more information:
John Immelman
phone 1300 363 707
fax 02 8877 7099
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