Michter's builds this from the same sour mash whiskey behind its standard US★1 Sour Mash, distilled in Kentucky to Master Distiller Dan McKee's specifications by the classic sour mash method — where a portion of a previous fermentation is carried into the next to hold consistency. The grain selection is not published, and it is the reason the whiskey falls outside both the bourbon and rye categories rather than being a variation on either. The spirit is filled into new American white oak at 103 proof, a low barrelling strength that yields less whiskey per barrel than a higher fill would. The barrels are both toasted and fire-charred, a two-stage cooperage that builds a different set of wood sugars than charring alone. Maturation runs until Michter's Master of Maturation Andrea Wilson and the tasting panel judge the barrels ready to batch, at which point they are married in small quantities and bottled at barrel strength — each barrel at whatever alcohol level it has reached, which is why the release carries a range rather than a number. A final filtration step, run to Michter's own specification, is the last thing between barrel and bottle.

Every bottle sold through Midnight Whiskey is sourced as an authentic, sealed product and inspected before it ships. Orders are packed with padded, glass-rated handling and require an adult signature (21+) on delivery; we do not ship to anyone unable to verify legal drinking age. For our full sourcing and handling protocols, see our editorial and authentication standards.

What proof is Michter's Barrel Strength Sour Mash?

It varies from bottle to bottle by design. Michter's bottles each barrel at whatever strength it has reached and states plainly that the alcohol by volume varies — for the 2026 release, bottling strength ran from 110.4 to 112.6 proof. A figure such as 112.6 therefore identifies one bottling at the top of that range rather than the release as a whole, so the strength printed on the bottle in front of you is the only exact answer.

Is Michter's Sour Mash a bourbon or a rye?

Neither, and that is deliberate. Michter's states that the grain selection behind its sour mash means the whiskey cannot be categorized as a bourbon or a rye — it is built to sit between the two. It is made by the classic sour mash method and matured in new charred white oak, and it is labelled as Kentucky Sour Mash Whiskey, which is a category of its own rather than a variation on either.

What is the mash bill of Michter's Barrel Strength Sour Mash?

Michter's does not publish it, and this page does not guess one. The distillery says only that its grain selection is distinctive enough to place the whiskey outside both the bourbon and rye categories. What is documented is the process rather than the recipe: distilled in Kentucky by the sour mash method to Master Distiller Dan McKee's specifications, filled into wood at 103 proof, and matured in toasted and fire-charred new American white oak.