The absolute most important aspect of a bourbon’s production is the mash bill – the grain recipe that is used to give a bourbon its distinct flavor. By changing up the recipe, distillers can change the taste, texture, and character of the bourbon.
We have discussed the sources of bourbon flavor in this previous article, but in terms of how different grain affect the flavor of bourbon, here is a quick recap:
Corn – Corn gives bourbon its distinct sweetness and provides the highest yield of alcohol per bushel of all the grains.
Barley – Barley is a beast when it comes to converting grain starches into sugar during the fermentation process so the yeast can feed on the sugars. Barley lends some flavors of chocolate and malt (surprise, surprise).
Rye– Rye adds a spice kick of pepper, allspice, and cinnamon. Rye in fact carries the majority of bourbon flavor.
Wheat – Wheat sweetens and softens the texture of whiskey.
Of course we know that bourbon must be 51 percent corn, but by manipulating the type of corn used or the percentages of grain used in the remaining 49 percent of the mash bill, you can accentuate or mute the flavors above.
One of my favorite Bourbonites made the bold statement that there are only three legitimate mash bills. They are:
The Traditional Recipe – 70-80% corn –with the balance rye and some barley. Think of sweet and spicy, back of the tongue experience. Bourbon can be up to 100% corn, but corn becomes neutral during aging only keeping the sweetness, so a flavoring grain of rye is used, and of course the barley for converting those starches in to sugar, and that biscuity quality and hints of chocolate.
The High Rye Bourbon Recipe – 18% + rye – dials back on the corn, keeping basically the same amount of barley as a Traditional Bourbon, but doubles up on the rye. Rye is a back of the tongue experience, and gives it that nice white pepper spice like a slice of rye bread. These bourbons will be less sweet and more spicy.
The Wheat Bourbon Recipe – 70-80% corn – similar to Traditional, but replace the rye with wheat. Wheat allows the sweetness of the corn, and the sugars from the barrel to be more pronounced. Think “soft and sweet”, with a front of the tongue experience.
The presumption is that very minor changes in mash bill dont contribute nearly as much to flavor as distillers would have you believe. But distilleries like Buffalo Trace have experimented with manipulating the big three recipes in ways that have produced fantastic results. For instance, their oat bourbon experiment produced a long finishing, peppery, smoky, hard-edged bourbon that is better than pappy in my book.
So beyond the big three mash bills, you have oat, rice, buckwheat, triticale, spelt, and even quinoa. Corsair is now even producing a 9 grain bourbon that combines all these grain into one mash bill (!)
And if playing Mr. Potato Head with the big-three mash bills wasn’t enough, distillers are getting snooty with the species of grain that they use. For instance, the Jim Beam Signature Craft Harvest Collection used soft red wheat. When it comes to barley, some bourbon distillers are moving towards natural barley malt (Hordeum vulgare L.) as opposed to gibberellic acid malt (aka the “gibb”).
While my bretheren in bourbon would argue that there are only three mash bills, I would argue otherwise. Whit so many variations on mash bill recipes, its becoming more difficult to just lump them all together under three banners.
And that’s a good thing if you ask me!