The limestone shelf where the distillery is located is key to crafting the unique taste of Maker's Mark – the only distillery with its own water source and watershed. Kentucky limestone filters out iron from water, which is unpleasant in bourbon. The pure calcium- and magnesium-rich water surrounding the distillery makes better drinking water and a better sour mash in which yeast can flourish.

Red winter wheat imparts the front-of-palate sweetness that Maker's^® is known for.