Question: what is the difference between cask ale and real ale?
Answer: Cask ale, also known as cask-conditioned beer or 'real' ale, is beer that undergoes secondary fermentation in the barrel. Brewers of cask ale don't interfere with it, they don't filter it and they don't pasteurise it. ... Just as Champagne evolves in the bottle, so too does cask ale mature and ripen in the barrel.