The 2 Kinds Of Bourbon That Have Minimum Aging Requirements

When it comes to brown spirits, it's easy to see why reaching for a glass of whiskey at the end of a long day is a no-brainer. That said, designations can be confusing for even the most academic drinker. There's scotch whiskey and Irish whiskey, spicy rye and subtly sweet bourbon — not to mention an entire slew of variations within each category that clock in at different alcohol levels, have different finishes, or boast a huge range of ages stamped on the bottle.

Like certain types of wines (think prosecco, chianti, champagne), certain spirits have standards of identity — meaning parameters and specifications they must meet in order to be classified as a particular product. These classifications can be meaningful to consumers in understanding the origins of their spirit and also have quality and pricing implications. Bourbon is different from whiskey because of those requirements, and the distillers that carefully create these liquids must take those rules seriously or risk their product's legal definition.

While it could take a particular level of dedication to understand all of these specifics, one question many bourbon enthusiasts may ask when choosing a bottle is whether there's a minimum age mandate in order to earn the moniker. Perhaps surprisingly, this isn't a material factor for most bourbons, with the exception of two categories: straight bourbon or bottled in bond.

To call a spirit "straight" bourbon might seem like an unnecessary qualifier, however so many whiskeys are blended that this label is useful for determining quality, depending on your priorities. Straight bourbons are not mixed with any other spirits. This is a distinction from those bourbons that are blended with neutral grain alcohols and have color added (a way for producers to get more bang for their buck through dilution), and ensures a reliable level of purity as added coloring or flavors are also prohibited. 

It's important to note, however, that although straight bourbons cannot be blended with other spirits, they can be combined with other straight bourbons, but they must be from the same state, for consistency. This category also requires that the whiskey be no less than 40% alcohol by volume (ABV) at bottling, but no more than 95% ABV, and be aged in new charred oak (and here's where that aging requirement comes in) for a minimum of two years.

Bourbons that are "bottled in bond" take the dating process to the next level, meeting all the requirements of straight bourbon, but aged longer, making their minimum aging time four years, and these liquids must also be created and distilled in one production season by a single distillery. In order to claim these designations, both bottles of straight whiskey and bottled in bond must assert their age on the labels to let consumers know what they're getting.

Aging is done not only with whiskey and bourbon whiskey, but many spirits from types of tequila and cognac to brandy and rum. The reason for aging is in part to help soften the alcoholic bite. Freshly distilled spirits can be intense, and aging time allows them to mellow.

Often, spirits like whiskey and some tequilas are aged in barrels, and in addition to making them more approachable and smooth, the wood imparts flavor and characteristics that change the drinking experience. Certain woods and char levels will come with their own personalities, and some distillers even employ used barrels to create new and different profiles (think whiskey aged in port barrels, or scotch in sherry casks). This is a creative choice distillers use to manipulate the flavor and experience of their finished product and is why you can have the same spirit made during the same season and aged for the same amount of time, and still end up with differing flavor profiles if they come from a diversity of barrels.

Of course, aging is a costly process for the distillery, and so it makes sense that certain liquors aged longer would fetch a higher premium. Since a good bottle is always a personal investment, being informed on the rules and requirements is a big help, but whether you opt for an aged straight bourbon, a bottled-in-bond option or any other variation, relying on your own preference is always the best guide.