Distillers Turbo yeast 18-20%. With this Turbo one can sometimes ferment large batches to 18% by adding 1/3 of the sugar at the beginning, and 2/3 of the sugar after one week. This is normally impossible with high alcohol Turbos, because when alcohol content reaches 14% or so and the temperature is too high, the heat kills the yeast and fermentation stops prematurely.