Gosh - come back from Lidl, pour a beer ... and this thread has grown a bit!
There are 2 systems of this type of keg and you need to know what you're dealing with ...
Mini Kegs come with a top tap system. These can be pressurised with co2 or IIRC you can get a pumpable tap system.
Easy Kegs are the same size / shape but have an integral bottom tap and are vented at the top via an openable bung. This lets air in and the beer will then start to deteriorate (although I find that opening to pour and then closing again maintains a reasonable co2 pressure and helps it to last at least a week ... ha chance would be a fine thing! :drink:)
5 litre kegs available in supermarkets are
usually the Easy Keg type ... although there are some other systems in use. I have seen them on sale with many different commercial beers and probably will change according to your part of the country. Beware that not all have the same type of bung and not all bungs can be removed without destroying the the bung! However, the orifice will be the same size and replacement re-usable bungs are available -
http://www.brewuk.co.uk/easy-keg-bung.html - The type of bung in that link is easily removable and can be re-used many times. That type of bung is used on Old Speckled Hen / Golden Hen / Summer Lightning available in large Tesco and Waitrose (amongst others probably). I have had to destroy the bungs in Hobgoblin, Bath Ales and Lidl Weissbeer but the bungs mentioned above will fit.
Prime as usual ... I use 20gms dextrose for an ale and prime with 175ml apple juice for my lady's turbo cider. Transportable without disturbing too much sediment IME.
Cleaning ... I rinse vigourously with hot water immediately when empty, seal with bung and then sanitise with Starsan before filling. Be careful as I have found that too much use of VWP can destroy the plastic lining! At least I think it was caused by the VWP. This procedure has served me well but I guess an oxy cleaner would also be OK to use.
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