How Understanding a Mash Bill Helps You Find Whiskey You Love

What is a Mash Bill?

A mash bill (also referred to as grain bill, mash ingredients, mashbill, or just mash) is the recipe used for a bottled spirit, most often in conjunction with whiskey.

What is Whiskey?

Whiskey is defined as a distilled grain spirit, usually aged in barrels. “White dog” or “white whiskey” refers to unaged whiskey because aging in wood barrels adds the color whiskey is known for. Rye, wheat, malted barley, and corn comprise the four main grains used today in whiskey. There are currently thirteen subcategories of whiskey, each defined by a region, minimum percentage of the above-mentioned grains, or both.  

All whiskey must be made with 100% fermented grain and each kind of grain brings a different flavor profile; refer to the image to the left for a quick overview on the 4 major ones used in 99% of production. This can help you gain a more well-rounded understanding of mash bills for new or unfamiliar bottles.

How can this help you find whiskey you love and save you money?

Okay, so we know what a mash bill is, we know what whiskey is, and it make sense this will help you make more knowledgable purchases. Now what the hell does this have to do with your wallet? Yeah, there can be some leather-y notes in a whiskey, and your wallet is made of leather… but that isn’t what we’re talking about here.

Being able to discern what a whiskey will taste like before buying it is a superpower I think everyone should have. This isn’t an exact science and it can take a while to perfect, but it’s so worth it. By knowing which whiskeys use a majority of which grains, you can get a good idea what  it will taste like. The rest of the mash bill will have influence, and so will ageing processes and timetables. So, let’s break it down.

Bourbon

Bourbon is, by law, at least 51% corn. As mentioned in the reference infographic above, corn adds sweet and herbal flavors. The majority of Bourbon contains around 70% corn in the mash bill. Bourbon is largely considered a sweet option for whiskey due to this prominence. The ageing process does have a strong influence on Bourbon, however. Corn is easily influenced, and sometimes overpowered, by the charring of the barrel it ages in. Another law that Bourbon must abide by, is that it must be aged in new, charred oak barrels. The longer this kind of whiskey is aged, the more oak influences you’ll pick up on- vanilla, caramel, toffee, baking spice, etc. This also dilutes some of the more delicate herbal flavors that corn contributes.

The other part of the mash bill (up to 49%) can be one other grain, or a mix of other grains. These usually include the three other main grains of wheat, malted barley, and rye. However, some distillers are experimenting with interesting choices such as quinoa and rice. Because the other main grains are not as easily influenced by the ageing process, they tend to hold their flavor profiles more readily. A heavy rye influence (Montana Whiskey Co. has a 51% corn and 49% rye) will taste spicier than most other bourbons. The majority of corn in the mash mellows the bottle out, but you will notice the rye before you notice the corn.

Scotch and Irish Whisk(e)y

Scotch and Irish whisky largely use malted barley as its base grain. This will provide a malty or grainy profile—I normally get cereal flavors from malted barley. You will see more Irish whiskies branch out into other grains such as wheat for a base, however malted barley still ranks in the majority.

 The ageing process for most of these whiskys is done in used barrels, meaning that the ageing process does not have as much of an influence due to the wood. The used charred barrels will have more of an effect on the finish of these whiskeys, making it more rounded and less harsh. You’ll still get a bit of the vanilla, caramel, or baking spice characteristic from the oak, but it’s an elevation of the flavors already present vs. an addition to the spirit.

One process that has a large influence on Scotch production is the addition of peat to the kilning of the malt. Peat is a type of moss used to add a smoky element that is widely associated with Scotch, although it isn’t widely used in each of its regions. However, peated whiskey can be found all over the world. All five regions of Scotland each have distinct characteristics attributed to the whiskies produced there.

Non-category Whiskeys

Each of the whiskeys named after a specific grain must contain a majority of that grain—at least 51%. The first example of this would be Rye whiskey. Because of the majority rye grain, it will pull a bulk of its flavor profile from that grain. If you aren’t into bold, spicy whiskey—or just don’t like rye bread—maybe ease into it. Whereas Wheat whiskey will be super mellow, really easy, and a little nutty, like my favorite people. Sometimes, wheat will be malted, like barley, to add some complexity to whiskey. It is mostly done for wheat used in Bourbon, but can be added to any wheated whiskey. The malting process for wheat also increases the sugar level and adds citrusy notes.

Corn Whiskey, which has a minimum of 80% corn, is the exception in this category. Here’s where you ask, “Wouldn’t that make it Bourbon?” and we answer, “Well, technically no.” Bourbon has to be aged in new oak barrels, and corn whiskey does not”. By ageing in used oak, corn whiskey is able to retain a lot of the delicate notes since, as discussed before, corn is easily influenced by oak. A great example of corn whiskey is Balcones Baby Blue. We use this a lot in our Bourbon tasting classes to demonstrate the influence of new charred oak on a majority corn product.

What about those whiskeys that don’t fit into one of these neat categories? Well, that’s what the grains are for! Once you learn what each of those add to a spirit, you can take on any whiskey with an educated guess. The ever-vague American Whiskey just has to be made in America, with no base grain specified. That’s really where this new knowledge will shine!

Buy Wisely

After mastering what a mash bill is, and what those grains mean, you need to learn your palate. We have a great article on tasting whiskey in case you would like a refresher course. It deals with mainly American Whiskey, but the techniques hold true across the board.

From now on, you will be able to go into any liquor store and pick a whiskey wisely. It will be easier to pick a host gift for the holidays, get that Scotch lover something you know he’ll love, and that newly minted Bourbon connoisseur something that will knock his socks off (and keep your wallet fat).

Will you be right 100% of the time? No. Will some whiskeys keep their mash bill a secret? Yes. Is tasting whiskey fun even if you don’t love every single one you taste? Hell yes.