It was not until May 4, 1964, that federal regulation recognized bourbon as a unique product and put specific laws on the books to ensure quality standards of bourbon.
What Makes it Bourbon?
At least 51 percent of the grains used to make straight bourbon must be corn, with the rest permitted to be a mixture of certain grains, usually malted barley, and rye, or sometimes wheat. It must be potted in new, charred, white oak barrels and aged at least two years.
Its strength usually runs between 80 and 125 proof, with the legal minimum strength being 60 proof. Proof is exactly twice the percentage of alcohol, thus a bottle which is 60 proof would be 30 percent alcohol.
Only limestone-filtered spring water (which is virtually iron-free) may be used to lower alcohol content. Although bourbon can be made anywhere, only Kentucky legally has the right to have the state's name on the label as a "bourbon" product.
Blended bourbon must contain at least 51 percent of straight bourbon.
Sipping whiskeys are more refined versions of bourbon, usually using a filtering process to mellow and remove the taste of the grain and requiring a longer aging period. One example of sipping whiskey is Jack Daniels, which is made in Tennessee.
Other popular bourbon varieties include Jim Beam, Maker's Mark, Wild Turkey, Early Times and Old Forester, all of which have single barrel (undiluted and uncut from one single barrel) and small batch (which takes the cream of the crop from several batches and co-mingles them) varieties offered at a higher price.
Nearly 80 percent of the world's supply of bourbon is made in Kentucky by thirteen distilleries. The rest is made in Tennessee, Virginia, and Missouri.