Special Edition: Beverage Processing

Optical technology could end 'out of spec' beer losses

By Jane Byrne

- Last updated on GMT

Related tags Brewing

Factors such as faster filling speed and reduction of beer waste have accelerated the take up over the past 18 months of optical technology for oxygen measurement by leading breweries in the US and Europe over the well established amperometric systems, reports supplier Mettler Toledo.

In the third part of FoodProductionDaily.com’s special edition on beverage processing, we look at how the global supplier’s combination of Intelligent Sensor Management (ISM) and optical technology – the InPro 6970i/M400 system - is helping beer producers lower production costs.

Bruno Aondio, head of international sales at the global process analytics company, told this publication that its optical system now accounts for 50 per cent of sales in terms of Mettler’s range of oxygen analytics instrumentation for brewing as it minimises beer losses in the filling process.


He said the brewing industry is quickly recognising that optical technology has significant advantages over amperometric systems in terms of its quicker response time at trace levels of oxygen, reduced signal drift, shorter maintenance time and longer maintenance intervals.

“The leading beer makers are in a transition phase in terms of switching to optical over amperometric oxygen measurement, with only a low percentage in the US, Europe and Asia having already replaced their electrolyte based system with an optical sensing one.

However, as awareness increases in the brewing sector of the tremendous efficiency gains and enhanced process control provided by optical technology, we anticipate rapid growth in the category over the next few years,”​ comments Aondio.

Rapid response

In the filler line of breweries, very low dissolved oxygen levels have to be measured and the detection of changing oxygen levels has to be very fast to prevent filling from ‘out of spec’ beer.

Aondio notes that oxygen measurement based on the traditional amperometric systems takes anything from 10 to 30 minutes as its response time is determined by the permeability of oxygen through the measurement membrane, whereas the reaction time of the optical equivalent, which is based instead on fluorescence quenching technology, is seconds.

“The fast response time enables the user to start the filling process much more quickly after a switch from rinsing water to beer, and consequently possible beer losses are reduced,” ​he maintains.

A high percentage of existing in-line dissolved oxygen sensors suffer from a “stop of flow” effect, said Aondio, which means that when the filler is stopped the resulting increasing oxygen reading of the sensor is often the cause of false alarms in the process control system: “With an optical oxygen measurement system a stop of flow effect is negligible.”

Maintenance planning

Unscheduled downtime of a filler line caused by a malfunction of a sensor is time consuming and costly but the Mettler spokesperson said that its optical InPro 6970i/M400 system also incorporates ISM based diagnostics tools to predict the remaining lifetime of an oxygen sensor and determine when the next calibration is required.

“Filler lines run more or less continuously with interruptions to the filling process typically very short such as during a change of the beer brand or cleaning of the plant.

Consequently, the time available for sensor maintenance is brief, and unscheduled downtime is very costly and our optical oxygen measurement system is characterized by its ease of maintenance,” ​said Aondio.

And instead of a membrane body, inner body and electrolyte associated with amperometric systems that all require maintenance, the optical system has only one component, the OptoCap, that needs to be replaced periodically, he said.

Cleaning cycles

The highest moments of stress for an optical oxygen sensor are during CIP cycles but Aondio said that ISM component of Mettler’s optical technology also allows the InPro 6970i/M400 system to detect CIP cycles automatically as well as the number of cycles is stored in the sensor memory.

The user is able to predefine a maximum number of CIP cycles for each unit. The measurement system automatically recognizes if this limit is reached and generates a maintenance request. As a result, any unforeseen failure of a sensor is very unlikely​,” he added.

FoodProductionDaily.com looked at the different water treatment requirements options facing soft drink manufacturers​ in the first part of the series and examined how natural’ juice trends are driving aseptic packaging and filling innovations​ for the second edition in our evaluation of current beverage processing trends.

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