Why Do We Say a Fifth of Whiskey, Rum, or Vodka?

Posted on 11 Mar 2015 05:47

When we go to buy a "fifth of whiskey" we are actually, today, buying a bottle that contains 750ml of liquid. We Americans, of course, will want to know how many ounces in a fifth. 750 milliliters is just about 25.4 ounces. This amount is the same as a standard wine bottle.

The term fifth, however comes from when bottles were 4/5 of a quart, which is the same as 1/5 of a gallon.

We no longer measure bottle sizes by fractions of a pint or gallon, and the term fifth may be archaic. However, 1/5 gallon, or 4/5 quart is 25.6 ounces, which is so very close to 750ml (25.4oz) that we still use the term fifth to describe this size bottle.

The fifth stopped being the standard size of a U.S. liquor bottle on January 1, 1980. Look at the explanation above, and you may start to see why. Why didn't a bottle of liquor contain a quart? Why only 4/5 of a quart? These 4/5 quart bottles were called "short quarts" or "commercial quarts." This had to do with the difference between being a liquor wholesaler versus a liquor retailer, and selling liquid by the quart was a general threshold for wholesaler. Although the laws governing the definition of a retailer differed by state, it was common for a customer to ask for a quart from a retailer and get something a bit less than a quart, but which was still called a quart.

Imagine if supposedly quart size didn't have a quart in them? Would you know? Now imagine if liquor came in 40 different size bottles. It did! For years.

Efforts began as early as the 1960's to eliminate the confusing fractions brought about by the the pint, quart, and gallon measurements and by the late 1970's efforts were underway to convert liquor bottle sizes to the metric system. Are you old enough to remember when we were "just about to switch to metric" and you had to try to learn the new system in grade school? Well, liquor is one of the only things we've managed to switch, the other being soda bottles. We Americans have our priorities, and it's liquor and soda, God bless our hearts.

fifth of whiskey, gin, scotch, 575ml

Fifth of Sour Mash Whiskey, Tanqeray Gin, and Dewars Scotch, which are 575ml or 4/5 quart
The Drambuie is a "pint" which is actually 375ml, or 4/5 pint

The new law took away most of the old bottle sizes, and made liquor available in the modern "fifth", the now familiar 750ml, as well as a 1.75 liter bottle, a liter, 500 milliliters, 200 milliliters, and the minis, 100 milliliters and 50 milliliters, equivalent to a shot, depending on who you ask.

After the switch, a fifth became 750ml, shaving off 7 milliliters. A quart bottle became a liter bottle, adding about 53.5ml. Half gallon became 1.75 liters, subtracting about 143ml. One pint (actually 4/5 pint) is now 375ml, deleting 98ml, although 500ml bottles existed until June 30, 1989, when they were phased out. A half pint became 200ml, around 36.6 less. You can rest assured that we paid the same whether the amount was reduced or not. To make it more clear, I've included a table below, giving the metric liquor bottle sizes, the equivalent ounces (approx.), and there supposed correspondence in terms of gallons, quarts or pints.

Bottle Size, metric Ounces Gallon, quart, pint "equivalent"
1.75 liters 59.2oz. 1/2 gallon
1 liter 33.8oz. 1 quart
750 milliliters 25.4oz. 4/5 quart, a "fifth"
375 milliliters 12.7oz. 4/5 pint
200 milliliters 6.8oz. 1/2 pint
100 milliliters 3.4oz. 1/4 pint
50 milliliters 1.75oz. 1, 1.6, and 2 ounce

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