What is the smoothest bourbon?

Quick facts

• "Smoothest" is a tasting impression; no federal rule defines smoothness or grades bourbon for it.
• Four factors drive it: proof, age, the mash bill, and which grain fills the non-corn slot in that bill.
• Bourbon must reach the bottle at 80 proof or higher, and there is no upper limit.
• Bourbon has no minimum age, while straight bourbon is aged at least two years.
• Wheated bourbons, Maker's Mark among them, put wheat where most bourbons put rye, and many drinkers read that as softer.
• A few drops of water lower the proof in the glass and change what you taste.

Why smoothness has no official standard

The federal standards of identity for whisky (27 CFR 5.143) set what a bourbon must be, and none of it concerns taste. They fix the country, the grain, the wood and the strength. Bourbon is American. Corn makes up at least 51% of the mash. The barrel is new charred oak. Proof is capped going in and floored at bottling. Every one of those settings moves flavor, and none of them measures it.

Some drinkers use smooth to mean low burn, some mean sweet, some mean an absence of the peppery bite that rye brings, and some mean a finish that stops rather than lingers. Those are four different requests, and they point at four different bottles with little in common. What holds steady is the machinery underneath.

Proof, the lever you feel first

Proof is the lever most drinkers notice first, and it is alcohol by volume doubled. Cask strength releases sit far above the 80 proof floor. Two other numbers shape the spirit before that: bourbon is distilled to no more than 160 proof, and the spirit enters the barrel at 125 proof or less. The distillation cap stops bourbon being stripped to a neutral spirit, and that cap is part of why bourbon carries flavor at all. Water is the only thing a distiller may add at bottling, and proof is what it moves. You can move it yourself with water or ice.

Age, and what the barrel gives and takes

Time in wood softens a bourbon up to a point, then starts working against it. Aging happens in new charred oak containers, and the char strips harsh notes while the wood gives vanilla, caramel and color. Past a certain stretch, oak stops rounding and starts drying: tannin builds, and heavily aged bourbon can taste woody rather than soft. Age statements are therefore a poor shortcut: a younger bottle can read smoother than a much older one. Our page on what straight bourbon whiskey means covers those label rules in detail.

Mash bill, the recipe under the flavor

The mash bill decides the shape of the flavor before a barrel is involved. Bourbon starts on a mash that is majority corn, at least 51%. Corn brings sweetness and body, so a high corn share tends to taste rounder and less sharp. The rest of the mash is where distillers differ. Malted barley usually takes a small share for enzyme activity, leaving one slot to argue over. Most Kentucky bourbons fill it with rye, and rye delivers pepper, mint and a dry, sharp edge that many tasters read as bite. A high-rye bourbon can be excellent and still land as anything but smooth; how high-rye bourbon overlaps with rye whiskey is set out on its own page. If you want less bite, that slot is the thing to change.

Wheat in place of rye

Wheated bourbon is the usual answer when someone wants softer, and the reason is that one grain swap. Wheated bourbon uses wheat instead of rye as the secondary grain, which reduces the peppery edge and leaves corn sweetness and barrel notes further forward. Maker's Mark is the best known example: red winter wheat fills that slot in place of rye, and tasters generally describe the result as rounder and less peppery than a rye-built Kentucky bourbon. W.L. Weller, Larceny and Rebel are also widely known as wheated bourbons. Softer is not weaker, and several wheated bottles are released at high proof, which brings the first lever back into play. Our Maker's Mark distillery visitor guide covers the distillery where that wheat mash bill is made.

Using the four levers on your own palate

Treat the four as a set rather than a ranking, because they pull against each other. Match the lever to what you mean by smooth. If you mean less heat, choose a lower proof, or add water to the glass before you write a bottle off. If you mean less pepper, choose a wheated bourbon rather than a high-rye one. If you mean less wood, choose a bourbon with some age but not the oldest statement on the shelf. If you mean sweeter, look for a mash bill heavy in corn. Then test your own conclusions side by side, because a tasting where two bourbons sit next to each other teaches more than any list. Our guide to bourbon distilleries in Kentucky sets out who makes what and where they sit.

Frequently asked questions