What is a Mash Bill?

What is a Mash Bill?

A mash bill is the grain recipe use to make a bourbon, rye or any type of grain spirit. The grains are mixed with water and yeast, cooked and fermented to create a ‘mash’.

The typical grains used in a bourbons mash bill are corn (at least 51%), rye and malted barley. A ‘wheater’ use wheat in the place of the rye and a Four Grain will use all four grains.  

Sour mash refers to the process where already distilled mash from a previous batch of mash is used in the fermentation of a new batch. The acid introduced by using the sour mash controls the growth of bacteria and creates a proper pH balance for the yeast to work. By using an established and known fermented ‘sour’ mash the consistency of the liquor is improved which eases production. 

Sweet mash is where only fresh water, grains and yeast are used in the fermentation process each time. It has a higher pH, meaning the mash ferments differently, producing flavours not generally found in sour mashes. The method makes it harder to produce consistency.