Maker's Mark are very fussy about their water, and source it only from a ten acre limestone spring lake next to the Distillery. Maker's Mark are equally choosy about selecting the grains that go into their Whisky. Yellow corn and red winter wheat from specially selected small farm cooperatives, all of which are located within the local limestone geology, gives Maker's Mark its soft, mellow taste. Maker's Mark is currently the only operating Bourbon Distillery to make Whisky in batches of less than nineteen barrels, the traditional standard for grand old American Whisky.

Maker's Mark only use naturally malted barley. By using an open cooker and a slower process that involves a lot of hands on attention, Maker's Mark extend the subtle grain flavours into their Whisky. Maker's Mark are among the few remaining Bourbon Distillers that propagates its own yeast for fermentation with cultures that can be traced back to before prohibition. Maker's Mark also use the traditional sour mash method, similar to making sourdough bread, where culture from one batch is used to start another. Rare cypress fermentation tanks are historically irreplaceable. Some of the planks are more than 100 years old.