Alcohol proof and percentage. What’s the difference and purpose?

Question

Alcohol proof and percentage. What’s the difference and purpose?

In: 4

Answer 1

One easy way to tell the alcohol content is to see if it can be set on fire. Any alcohol percentage above 50% is flammable but people back in the days couldn’t measure the alcohol percentage directly.

Thus they set the lower limit of a flammable alcohol beverage (50%) to a proof value of 100. That proof can then be diluted to lower levels. As a coincidence, the proof value is double the alcohol percentage.

Answer 2

One easy way to tell the alcohol content is to see if it can be set on fire. Any alcohol percentage above 50% is flammable but people back in the days couldn’t measure the alcohol percentage directly.

Thus they set the lower limit of a flammable alcohol beverage (50%) to a proof value of 100. That proof can then be diluted to lower levels. As a coincidence, the proof value is double the alcohol percentage.