By Karin Pawlowsky - 28 February 2013

Even though drinks manufacturers may have produced immaculate beverages, the drink presented to the customer may be unacceptable if contamination has occurred at the point of dispense. The resulting defects can be visual, such as turbidity in the drink, or affect the flavour of the drink with off–flavours forming. As a consequence the consumer may turn away from the brand and business is lost.

From a hygiene point of view, there is a lot to consider when dispensing beverages, such as beer in a pub or juice through a dispenser. The drink will be more or less susceptible to contamination depending on its chemical composition and the conditions it is dispensed under.

There are many points in the dispensing process where microbiological contamination can occur - at the coupling of the drink package to the dispense system; through the dispense equipment, which can be quite complex; and at the dispensing tap. Micro-organisms, usually introduced due to insufficiently clean equipment or from the environment, will settle on surfaces in the system (e.g. tubing) where they attach, grow and excrete carbohydrate leading to a protective slime layer. Over time a microbial community consisting of a mix of bacterial and yeast species develops - this is the so-called biofilm. The microbes present in the surface biofilm can then be released into the drink as it passes through the system on its way to the tap.

Once a biofilm is established it is very difficult to remove and a simple chemical clean is usually insufficient. Therefore it is of utmost importance that the dispense equipment is cleaned effectively on a regular basis to prevent any biofilm from developing. We can help to determine suitable cleaning schedules for specific dispense situations.

We also regularly work with suppliers to the beverage dispense industry assessing the suitability of new devices which may be useful at extending system cleaning frequency. Additionally, we can determine whether the hygienic design of new dispense equipment (e.g. connectors, carbonators) is adequate by assessing microbiological build-up and their 'cleanability' compared to the existing standard equipment currently in use.

Many novel dispense cleaning products are launched on the market. However, the people who clean the dispense systems don't often have the time and money to test these new products. We are able to carry out such assessments independently and results are available to interested parties on our instrument comparison website (http://www.compareinstruments.com/). The evaluation process usually includes testing for the effectiveness of the new product and possibly any effects on the dispense equipment and on the draught beverage quality.

Drinks manufacturers are constantly developing new products and may need an understanding as to the microbiological stability of their new beverages in a dispense situation. We are able to help by artificially ageing a replicate dispense system, i.e. introducing micro-organisms, and then monitoring the fate of the microbes as the drink is dispensed. Over time the microbial load in the dispensed drink and on the surfaces of the system may rise or fall, allowing an optimum cleaning frequency to be established.

Find out more about our food and drink hygiene activities.

Karin Pawlowsky, Senior Scientist
+44(0)1737 824268
karin.pawlowsky@campdenbri.co.uk