It does not require delicate handling or expertise in the pub cellar, apart from basic hygiene. The overriding disadvantage is the taste. Filtering, pasteurising, carbonating and chilling can produce, thin, gassy, characterless beer. On balance all the advantages tend to favour production rather than consumption. Real ale is allowed to continue fermenting in a conditioning tank.
Nothing is removed or killed.
After a few days it is put into casks. At this stage new ingredients may be added to improve the body or to add flavour. Finings, a fish derivative, is added to settle the yeast particles to the bottom of the cask. However the beer is still 'live' and continues to ferment and mature. When the cask reaches the pub, it must be kept at a constant temperature and be allowed to settle.