A pint is a pound, the world round.

The above rhyme is almost true (but good enough for most) and tells of specific gravity of water - and only water. One pint is 473.2 cubic centimeters, and one pound is 453.6 grams. The density of water is 1.00 gram / cubic centimeter... close enough.

The specific weight gravity of a liquid is the weight per unit volume and reflects grams per cubic centimeter. Because water has the density of 1 gram / cubic centimeter this makes things easier.

The term 'specific' refers to a ratio in physics. The specific weight or specific gravity is a measure of how much it weighs (or is attracted to the earth).

density of substance
sp gr = --------------------
density of water
It can be seen here that the density of water being 1 gram / cubic centimeter makes things much easier - essentially saying the specific gravity is the density of the substance over one, or even more simply the density of the substance is its specific gravity.

Oil has a specific gravity of 0.89 and glycerin has a specific gravity of 1.21. This can also be read as oil is 11% less dense than water and glycerine is 21% more dense than water.

Recognizing that this is driven by the density of the liquid, it is sometimes possible to juggle the items a bit by chilling them so that they are more dense and more viscous. Furthermore, realize that different brands of liquor may have different specific gravities. (There is a black vodka by the name 'Blavod' that sits in the pub I frequent - the bartenders say it will float on anything, though is not particularly good).

For drinks not listed below, one should look at the proof of the liquor which can be an indication of the specific gravity. Many times the proof of the liquor is determined by measuring its specific gravity. The Customs and Excise Act of 1952 in Great Britain declared that 100 proof is 12/13 the weight of distiled water at 51F (11C) - this would be a specific gravity of 0.92. Do note that percent alcohol by weight and percent alcohol by volume are different things - 100 proof in Great Britain would be 48.24% alcohol by weight and 57.06% alcohol by volume. The United States has 100 proof being 50.00% alcohol by volume.

Kirschwasser          0.94 Clear

Southern Comfort      0.97

Tuaca                 0.98 Amber

Ginger Brandy         1.00 Light brown
Water                 1.00 White

Green Chartreuse      1.01 Green

Kirsh                 1.02

Cointreau             1.04 White
Grand Marnier         1.04
Peach liqueur         1.04 Dark amber
Sloe gin              1.04 Deep red
Kummel                1.04 White
Peppermint Schnapps   1.04 White
Cinnamon Schnapps     1.04 Reddish
Benedictine           1.04
Brandy                1.04 Amber
Cherry Liqour         1.04
Cognac                1.04

Rootbeer Schnapps     1.05 Brown
Midori melon liqueur  1.05 Green
Rock and Rye          1.05 Amber

(Fruit brandy)        1.06
Apricot brandy        1.06 Amber
Blackberry brandy     1.06 Dark red
Cherry brandy         1.06 Dark red
Peach brandy          1.06 Dark amber
Campari               1.06 Red
Yellow Chartreuse     1.06 Yellow

Benedictine D.O.M.    1.07

Sanbuca               1.08 White
Strawberry liqueur    1.08
Drambui               1.08
Frangelico            1.08
Orange Curacao        1.08 Orange
Amaretto di Saranno   1.08

Triple sec            1.09 White
Tia maria             1.09 Brown
Apricot liqueur       1.09 Amber

Blackberry liqueur    1.10 Dark red
Amaretto              1.10 Light brown

Blue Curacao          1.11 Blue

Galliano              1.11 Golden yellow

Cherry liqueur        1.12 Dark red
Green Crème de Menthe 1.12 Green
White Crème de Menthe 1.12 White
Strawberry liqueur    1.12 Red

Parfrait d'Amour      1.13 Violet
Maraschino liqueur    1.13

Coffee liqueur        1.14 Dark brown
Crème de Banane       1.14 Yellow
Dark Crème de Cacao   1.14 Brown
White Crème de Cacao  1.14 White

Kahlua                1.15 Dark brown

Crème de Almond       1.16

Crème de Noyaux       1.17 Bright red
Anisette              1.17 White