Draught beer, also spelt draft, is beer served from a cask or keg rather than from a bottle or can.eg beer is a term for beer which is served from a pressurised keg. Keg beer is often filtered and/or pasteurised, both of which are processes that render the yeast inactive. A tap hole near the edge of the top, and a spile hole on the side used for conditioning the unfiltered and unpasteurised beer.