in <0x0A> </s> ▁Prem ix ▁and ▁post mix ▁are ▁two ▁methods ▁of ▁serving ▁– ▁usually ▁carbon ated ▁– ▁soft ▁drink s ▁that ▁are ▁alternatives ▁to ▁bott les ▁and ▁can s . ▁ ▁Prem ix ▁Prem ix ▁refers ▁to ▁a ▁ready - m ixed , ▁ready - to - dr ink ▁soft ▁drink ▁that ▁has ▁usually ▁been ▁pack aged ▁in ▁ 5 - g all on ▁st ain less ▁steel ▁t anks ▁called ▁Corn el ius ▁k eg s ▁( or ▁" C orn y ▁k eg " ▁for ▁short ). ▁ ▁The ▁prem ix ▁itself ▁is ▁identical ▁to ▁the ▁be verage ▁of ▁the ▁same ▁brand ▁that ▁is ▁sold ▁in ▁bott les ▁or ▁can s , ▁and ▁is ▁already ▁carbon ated . ▁The ▁soft ▁drink ▁is ▁passed ▁through ▁a ▁prem ix ▁disp enser ▁that ▁re fr iger ates ▁it ▁before ▁disp ens ing ▁it ▁through ▁a ▁pressure - comp ens ating ▁val ve ▁or ▁tap . ▁ ▁A ▁prem ix ▁disp enser ▁is ▁suitable ▁for ▁out lets ▁that ▁regularly ▁sell ▁the ▁particular ▁soft ▁drink , ▁but ▁in ▁relatively ▁small ▁amounts . ▁ ▁At ▁the ▁plant , ▁a ▁quality ▁control ▁manager ▁period ically ▁checks ▁the ▁carbon ation ▁level ▁of ▁the ▁prem ix ▁t anks ▁with ▁a ▁carbon ation ▁test er ▁before ▁ship ment . ▁ ▁Post mix ▁Post mix ▁refers ▁to ▁the ▁system ▁in ▁which ▁a ▁flav ored ▁sy rup ▁( con cent rate ) ▁of ▁the ▁soft ▁drink ▁is ▁sh ipped ▁to ▁the ▁ret ail er , ▁usually ▁in ▁a ▁return able ▁tank ▁or