What is the minimum proof at which bourbon must be bottled?

Bourbon must be bottled at a minimum proof of 80. This standard is set to ensure the quality and flavor characteristics of the bourbon are preserved when it is packaged for sale. Bottling at this proof level allows for a balance that maintains its taste while still offering sufficient alcohol content.

Proof is a measure of the alcohol content in a beverage, with the proof being double the alcohol by volume (ABV) percentage. Therefore, at 80 proof, the bourbon contains 40% alcohol by volume, which is typical for many spirits and provides a noticeable strength while still being palatable for consumers. Bottling below this proof would not meet the legal definition of bourbon, which is crucial for maintaining its classification in the marketplace.