Ale is brewed from malted barley, using a warm fermentation with a strain of brewer’s yeast. This helps speed up the fermentation process, giving it a sweet, full bodied and fruity taste. Whereas in larger the yeast from fermentation (the process which turns the fermentable sugars in the malt into alcohol and carbon dioxide) sinks to the bottom, in Ale it floats to the surface. Ales, including bitters, milds, stouts, porters and barley wines all use top-fermenting yeast, which forms a thick head on the top of the fermenting vessel. The process is shorter, more vigorous and done in higher temperatures than lager, and this is the traditional method of brewing British beer. Ale is a natural, living product and must be kept in the right conditions to enable it to mature and bring out the full potential of its flavour. Ales are not as fizzy as lagers; they have a gentle carbonation produced by the slow secondary fermentation in the cask, which gives the distinct taste and aroma associated with ale.