The shelf life and taste stability for filled beverage, especially for filled beer, are the key parameters of the plastic kegs.

for filled beer, during the shelf life, it requires the total oxyty less than 1000ppb, and the CO2 loss should be less than 10%, otherwise, the beer will be tasted old and/or flat; only stainless steel kegs and glass bottle can meet such requirements for the filled beer for a 6 months shelf life in the past several decades; it's a challenge for plastic kegs to meet such high requirement for a long shelf life, any single polymer is not possible to have so high barrier performance, that's why not possible for all the PET one-way plastic kegs to have long shelf life for filled beer, even if with aluminium foil or aluminium film inner bag in the plastic kegs, due to crack and/or damage of the aluminium layer after the bag folding, it's also not possible to provide so high barrier performance and the filled beer is not possible to have a long shelf life.

with years research on high barrier materials, Gpro Technology team is the first one and could be the only one in this industry at the moment who has the unique multi barrier technology for the plastic kegs; by combining the organic high barrier materials and the inorganic high barrier materials, the Gprokeg inner beer bags have both the properties of flexiblity and high barrier performance, to change the molecular motion pathways of O2 and CO2; and for the Gprokeg reusable plastic kegs, with both multi barrier material on the plastic kegs and the inner beer bags to form a double barrier bag system, the Gprokeg plastic kegs can provide extremely high barrier performance to both O2 and CO2, which is really comparable to the stainless steel kegs on the barrier performance; it proves from relative tests that for the filled beer in the Gprokeg plastic kegs, the O2 transmission per year is less than 0.3ppm, and the CO2 loss is less than 5% per year. this can guarantee a shelf life for the filled beer for 6 months or even up to 12 months base on the O2 transmission and CO2 loss.

besides the barrier performance and shelf life for filled beverages, another possible issue for the plastic kegs for filled beverages is that, it's possible that the plastic material change the taste of the filled beverages, especially for the filled beer; any small molecule from the plastic material migrated into the filled beer will cause possible relative actions, such actions will possible change the taste and flavour of beer. thousands of tests for hundreds of relative plastic materials prove that a lot of plastic material can change the taste and/or flavour of the filled beer, only for strong beer such change is not so obvious, but for light beer, it's a very obvious flavour change; especially for the plastic material used on the beer bags, most of the aluminum film beer bags on the market can change the flavour of light beer (pils, etc.) significantly.

Gpro Technology is the first one and also the only one in this industry globally who did research on plastic material for beer taste stability, with the unique technical solution for all Gprokeg plastic kegs, to prevent the small molecules migrated into the filled beer and the relative actions, the Gprokeg plastic keg is the only one which can guarantee the taste and flavour of the filled beer will be not influenced/changed by the plastic material, to keep the original/fresh taste and flavour of the filled beer during the shelf life.

in additional, for Gprokeg plastic kegs, all the spears and innner bags are radiation sterilizated, it's completely no germs in the spears and inner bags, the filled beer is to be free of germs contaimination;

as the beer is filled into the beer bags in the Gprokeg plastic kegs, the beer bags are well prepared and no additional cleaning and sterilization needed, no any chemical residue from the cleaning process into the filled beer, also takes risk away of the taste/flavour of the beer influenced by such chemical residue.

in beer dispensing, the pressure medium is filled into the space between plastic keg and beer bag for Gprokeg plastic kegs, not contact the beer in the inner beer bags, no matter what kind of pressure medium (CO2, N2, compressed air, etc.), there is no risk of contamination from the possible not pure/clean enough pressure medium and then change the taste/flavour of the filled beer.

as unique multi barrier technology, unique taste stability technology, and unique radiation sterilization technology used, the Gprokeg plastic kegs are the only plastic kegs which can really have long shelf life and 100% taste stability for filled beverages, especially for filled beer.