There are companies that now market special limestone water for mixing with your bourbon. They claim it’s the same water Kentucky distillers us to make bourbon. This might be true, but they omit the most important detail.
KY distillers use this limestone water only in the cooking of the mash and fermentation, never in the bottling. Limestone water is naturally low and iron and sulfur, both of those you don’t want in distillation. Limestone water also has magnesium and calcium which can act as nutrients for yeast during the fermentation process.
Limestone water is hardly unique to KY. Large limestone aquifers exist throughout the Southwest into Minnesota and Iowa and down to Florida.
Post distillation, all water used in the bourbon making process by any of the major producers is a pure as possible. The water is treated by reverse osmosis and deionization or other similar process to be as neutral as possible. No distillery would even consider using limestone water post distillation. No limestone water is used to cut white dog to barrel entry proof nor is it used to cut to bottle proof. Yet, companies want to sell you this special water for you to add to your bourbon.
The only reason you would buy this water is if you are tater. Specifically, tater reason #
33. Buy specialty ‘whiskey water’ to add to your whiskey vs tap or routinely available bottled water.