Ale is a type of beer brewed from malted barley using a top-fermenting brewers" yeast. Most ales contain hops, which impart a bitter herbal flavour that helps to balance the sweetness of the malt and preserve the beer. Ale yeast works best in moderate temperatures between 15C and 25C. Ale starts maturing after a few days of fermenting and lasts around two weeks. The warm conditions needed tor ale yeast to ferment allow the yeast to create esters and other secondary flavour and aroma products, and the result is often a beer with slightly "fruity" compounds resembling apple, pear, pineapple, banana, plum, or prune, among others creating full body, soft and round effect. Belgium produces a wide variety of specialty ales. In most of the cases Belgian ales characterize with relatively are high alcoholic content due to the addition of sucrose, which provides an alcohol boost with an essentially neutral flavour.