PETpla.net Insider 05 / 2014

BOTTLE MAKING 32 PET planet insider Vol. 15 No. 05/14 www.petpla.net Beer in PET - a never-ending story? Keg systems: A personal experiment For years, beer in PET bottles has occupied a niche posi- tion. Briefly fuelled by the introduction of the drink can deposit system in Germany ten years ago, it is becoming increasingly difficult to find the PET bottle being used for beer. Nevertheless, beer in PET seems to have an awe- some future in front of it, namely, in the form of beer in the PET keg. To give it the once over, so to speak, we have installed a KeyKeg dispenser in our Editourmobil, and you are cordially invited to join us for a refreshing glass of beer. At drinktec we found a number of suppliers courting the favours of the breweries. Featured are the classic PET kegs with standardised bayonet fittings as can be seen in practically any bar taproom. The headspace in the barrel is pressurised with gas – as a rule CO 2 – which means that the beer can be conveyed under pres- sure into the dispenser line via a hose or pipe. Suppliers of these systems include, for example, Dolium, Petainer and PolyKeg. The advantages of these systems are clear. The keg is single-use, so there is no need to clean it, nor, more importantly, is return transport required. This represents a significant advan- tage for breweries whose beer market- ing activities extend across national frontiers. Another key feature is that the range of different connections means that the bar owner is able to serve the beer via his normal tap system. Depending on the system, the disadvantage of all kegs, including the metal ones, is the need to pressur- ise the headspace with gas. Unless absolute cleanliness is scrupulously observed here, it will be possible for oxygen to get into the headspace – to the immediate detriment of the taste. Using a central tap system means that the existing beer lines are used. Gen- erally, bar owner will need to ensure that these are cleaned regularly, otherwise the taste of the beer will be affected. Two PET keg systems: two different paths At drinktec, Krones presented the Bevkeg barrel system, in which the headspace is eliminated from the keg, both during the filling and during the emptying processes. The empty keg looks like a salad bowl. The whole of the top section is curved inwards. Filling pushes the upper section out- wards without any headspace being formed. It is only when the keg is full that it assumes its typical shape. The process is reversed when emptying the keg: here a punch compresses the barrel mechanically so that the beer is forced out of the barrel. So as to avoid taking up the existing beer lines all at the same time, the keg is sup- plied with a single beer line only. The dispenser unit needs to be installed in the bar together with the keg. No provision is made for emptying via a central dispenser systems. Time will tell whether bar owners are ready to sacrifice valuable space in terms of refrigerator volume at the bar for just one type of beer. KeyKeg is the second system In this the PET keg does not come into direct contact with the beer. The beer is accommodated in an internal multi- layer bag. Initially the bag is under vacuum. The bag is then filled with beer. The area between the bag and the PET keg is pressurised so that the bag is, so to speak, pre-tensioned. As the level of fill increases, it will be pos- sible to release the pressure via a filler valve until the bag has been filled to capacity and is resting against the PET barrel. The emptying process then pro- ceeds in the reverse sequence. A compressor is used to pressurise the space between the bag and the keg and the beer arrives at the dis- penser. For simple bars the compres- sor is installed directly in the coolant dispenser, but of course there is no problem either in obtaining the pres- sure from a CO 2 bottle in the tradi- tional manner. This makes the system available for use with already installed lines, although its CO 2 -free dispenser facility means that it can also be uti- The Krones approach: BevKeg