What is the legal alcohol by volume (ABV) limit for distilling bourbon?

The legal alcohol by volume (ABV) limit for distilling bourbon is 160 proof, which is equivalent to 80% ABV. This limit is set by the regulations that define bourbon production. According to the U.S. Alcohol and Tobacco Tax and Trade Bureau (TTB), to be classified as bourbon, the distilled spirit must enter the barrel for aging at no more than 125 proof, or 62.5% ABV. The initial distillation process can take place at a maximum of 160 proof, allowing for the effective preservation of the flavor constituents that contribute to bourbon's unique taste. This distinction is crucial in ensuring that the final product adheres to the standards that define bourbon, focusing on the balance between alcohol concentration and flavor development during its maturation process.

The other options exceed the legal limit for distilling bourbon and would not comply with the definitions regulated by law. Thus, they are not suitable answers in the context of bourbon production.