well I watched the video alikav led me to and thought why not so went up morrisons and got a carton of pure concentrate grapefruit,cracked a bottle and started to add some to it and hey I may be able to drink this crap afterall as I do like grapefruit flavoured beer,worked out how much I added to the litre bottle and threw 14 litres of this trash beer out the bottles into a corny and threw in half litre of the grapefruit concentrate.gassed her up done a bit of purging and just gonna let it sit for a bit until I empty another cornie in the hope that some remaining yeast cells may awake and munch thru whatever sugars there are in the grapefruit concentrate,i will add an update as and when