Complex sentence: The cream ale from Kilkenny (beer) in Ireland is entirely different than North American versions; it is similar to Guinness with a nitrogenated cream head, but with "50% less carbonation than regular beers".
Split into simpler sentences: The cream ale from Kilkenny (beer) in Ireland bears no resemblance to North American made cream ales. It is similar to Guinness with a nitrogenated cream head, but with "50% less carbonation than regular beers".