Takamine Koji Whiskey is made with the patented Takamine Process, which uses an ancient Japanese mold, koji, to convert starches to sugars in a process similar to malting barley. Unlike malt whiskey where sugars are extracted in a warm water mash before yeast is introduced to start the fermentation, both the koji and yeast are active at the same time in a multiple parallel fermentation. This 100% barley ferment is then double-distilled and aged in virgin oak and ex-bourbon casks.