Why is it called a fifth of whiskey?

Answered by Ricardo McCardle

The term “a fifth of whiskey” has its origins in the historical measurement system used for liquor bottles. In the United States, a fifth referred to one-fifth of a gallon, which is equivalent to approximately 750 milliliters or 25.4 fluid ounces.

The term “fifth” began to be used to describe a standard-sized bottle of liquor around the early 20th century. At that time, the fifth was the most common size for bottles of distilled spirits. It was widely adopted as the standard size by most liquor producers and was commonly found on store shelves.

The reason it was called a “fifth” is because it represented one-fifth of a gallon, which was a convenient and easily understandable measure for consumers. It provided a consistent quantity of whiskey in a bottle that was easy to handle and pour.

However, it’s important to note that the size of liquor bottles has evolved over time. In 1979, the United States adopted the metric system for liquor bottle sizes, and the fifth was officially standardized as 750 milliliters. This change was made to align with international standards and simplify trade between countries.

Since then, the size of whiskey bottles has become more varied. Some bottles now hold more or less than the traditional fifth. For example, you may come across 700ml bottles or larger 1-liter bottles. These variations in size are mainly due to market demands and the preferences of both producers and consumers.

Despite the changes in bottle sizes, the term “a fifth of whiskey” has persisted as a colloquial expression for a significant amount of alcohol. If someone says they drank a fifth of whiskey, it generally implies that they consumed a substantial quantity and likely had quite a few drinks.

The term “a fifth of whiskey” originated from the historical measurement system used for liquor bottles, where a fifth represented one-fifth of a gallon. It became the standard size for bottles of distilled spirits in the early 20th century and has since been widely used to describe a significant amount of alcohol. While bottle sizes have evolved over time, the term “fifth” has continued to be used colloquially to denote a substantial quantity of whiskey.