How long does it take for a shot of alcohol to be processed by the liver?

About 60-90 minutes. That is an average but can vary from person to person based on genetics, sex, men tend to have increased metabolism, ethnicity, rate of gastric emptying. Increase activity or amount of liver enzymes from increase tolerance to alcohol. One drink is defined as 1.5 oz of 80 proof spirits, 5 oz of wine or 12 oz of beer.