Is a Fifth of Alcohol 1 Liter: The Shift from Fifth to 750 mL
The concept of the "fifth" in the context of alcohol has undergone significant changes over the decades. Historically, a fifth referred to one-fifth of a US gallon, equivalent to approximately 0.757 liters. Today, the 750 mL bottle has become the standard packaging size, replacing the traditional fifth. This shift took place in the late 1970s when the US conversion to metric units was finalized.
The Shift from Customary to Metric Units
Starting in the late 1970s, the wine and spirits industry in the United States, along with the Federal government, agreed to adopt metric bottles as a standard. Prior to this change, the fifth was a common custom-sized bottle that equaled one-fifth of a gallon. This amounted to approximately 0.757 liters. However, the 750 mL bottle was chosen as the new standard, and it has been the dominant size for both wine and spirits since the mid-1980s.
The Measurement of a Fifth
A fifth is one-fifth of a US gallon, which is equivalent to 0.2 gallons. To convert this to liters, we use the following conversion:
0.2 fl gal 0.7570823568 L
The imperial gallon, as used in the UK, is a much larger unit of measurement. A fifth of an imperial gallon comprises 160 fluid ounces, which amounts to about 4.546 liters, a far cry from the 750 mL that is now the standard.
Current Practice in the US and EU
In the United States, the 750 mL bottle is now the most common size, with other standard sizes allowed. This change was made to align with the metric system, which simplifies labeling and production processes. In the EU, while 750 mL is the standard size for wine, they also use 700 mL for spirits, marked as 70 cl (centiliters).
It's worth noting that the replacement of the fifth with the 750 mL bottle has led to common misconceptions among consumers. Many people still refer to 750 mL bottles as "fifths," a practice that is anachronistic and not based on any official standard. The 750 mL bottle is slightly under the 0.757 liters of a fifth but is close enough to maintain compatibility with traditional standards.
The adoption of the 750 mL bottle has also led to certain other standard sizes, such as 700 mL, 750 mL, and 775 mL, being officially recognized in various regions, including the EU.
In summary, the measurement of a fifth of alcohol has shifted significantly over the past few decades. While the concept of a fifth lingers in consumer awareness, the 750 mL bottle has become the standard, providing a more straightforward and accessible measurement for consumers worldwide.