Layered drinks

Layered cocktails do not create new textures or flavors but make a beautiful presentation, showcase all the ingredients and could add to the drinking or eating experience as different flavors or temperatures are experienced in turns. Layered drinks have been made for a long time but this technique is still being used today in creative ways by molecular mixologists and chefs to craft fabulous cocktails and dishes.

A layered drink, also called a pousse-café, is a cocktail in which various liqueurs are used to create an array of colored layers. They have been traditionally made by carefully pouring slowly one liqueur at a time over the back of a spoon but this process requires practice, patience and takes a long time. 
The Princeton cocktail, for example, starts off all gin and citrus, but the port at the bottom of the glass gradually makes its way to the sip changing the flavor. The layering technique can also be used to layer liquids at different temperatures to create a distinct experience, as the Irish coffee.

Layered drinks are based on the principle of liquid densities: sweeter liquids are heavier; drinks with higher alcohol content are lighter. To create layered cocktails, each ingredient is carefully poured into a glass or carafe starting with the densest liquid first and progressing to the least dense. If you want to change the relative densities of the liquids you are using, you just need to add sugar to increase density and add water (or alcohol) to reduce it.

The following table has the densities of popular beverages to help you create your own layered cocktail. The table is from 

Miss-Charming.com

NAME	COLOR	FLAVOR	WEIGHT
Cream	White	Milky	very light
151 Rum	Light Amber	Fire	light
Maker’s Mark Bourbon	Dark Amber	Bourbon	0.941
Hiram Walker Kirschwasser	Clear	Cherry	0.941
Dekuyper Kirschwasser	Clear	Cherry	0.941
Sauza Silver Tequila	Clear	Tequila	0.945
Jameson’s Irish Whiskey	Amber	Irish Whiskey	0.948
Rain	Clear	Vodka	0.9498
Sauza Gold Tequila	Gold	Tequila	0.95
Skyy Citrus Vodka	Clear	Lemon Vodka	0.9555
Pernod	Clear	Anise/Licorice	0.985
Ouzo	Clear	Anise/Licorice	0.984
Southern Comfort	Dark Amber	Peach Apricot	0.99337
Hiram Walker Ginger Brandy	Light Amber	Ginger Brandy	0.995
Tuaca	Amber	Vanilla Orange Caramel Brandy	1.0157
B&B	Amber	Sweet Herbal Cognac	1.0245
Dekuyper Sloe Gin	Dark Red	Sloe Berries	1.0261
Hiram Walker Peppermint Schnapps	Clear	Peppermint	1.027
Grand Marnier	Amber	Orange Cognac	1.03
Malibu	Clear	Coconut Rum	1.03
Hiram Walker Root Beer Schnapps	Brown	Root Beer	1.037
Cointreau	Clear	Orange	1.0385
Dekuyper Apricot Brandy	Dark Orange	Apricot	1.0437
Dekuyper Triple Sec	Clear	Orange	1.05
Chambord	Maroon	Black Raspberry	1.05
Lady Godiva White Chocolate Liqueur	White	White Chocolate	1.05
Baileys Irish Cream	Tan	Creamy Spiced Irish Whiskey	1.05
Irish Mist	Dark Amber	Honey Herb Whiskey	1.05
Dekuyper Blackberry Brandy	Dark Purple	Blackberry	1.0552
Campari	Red	Bitter	1.06
Benedictine	Light Amber	Herbal	1.07
Dekuyper Blue Curacao	Blue	Orange	1.0704
Dekuyper Root Beer Schnapps	Brown	Root Beer	1.0705
Drambuie	Light Amber	Heather Honey Scotch	1.08
Amaretto Di Saronno	Dark Amber	Almond	1.08
Sambuca	Clear	Anise/Licorice	1.08
Frangelico	Clear	Hazelnut	1.08
Tia Maria	Brown	Coffee	1.09
Dekuyper Anisette	Clear	Anise	1.0921
Dekuyper Melon Liqueur	Bright Green	Honeydew Melon	1.0924
Dekuyper Wildberry Schnapps	Clear	Berry	1.0894
Dekuyper Green Menthe	Dark Green	Mint	1.0885
Dekuyper Bluesberry	Clear	Blueberry	1.0863
Dekuyper Grape Pucker	Purple	Grape	1.0864
Dekuyper Banana	Yellow	Banana	1.0822
Marie Brizard Blue Curacao	Blue	Orange	1.0999
Dekuyper Coffee Liqueur	Brown	Coffee	1.189
Hiram Walker Crème de Noyaux	Red	Almond	1.148
Marie Brizard Coffee Liqueur	Brown	Coffee	1.142
Hiram Walker Crème de Banana	Yellow	Banana	1.142
Midori	Bright Green	Honeydew Melon	1.15
Kahlua	Brown	Coffee	1.152
Marie Brizard White Crème de Cacao	Clear	Chocolate	1.1602
Marie Brizard Dark Crème de Cacao	Brown	Chocolate	1.1602
Hiram Walker Crème de Cassis	Dark Red	Black Currant	1.179
DeKuyper Razzmatazz	Red	Raspberry	1.139
Marie Brizard Anisette	Clear	Anise	1.1371
Hiram Walker Dark Crème de Cacao	Brown	Chocolate	1.136
Dekuyper Buttershots Schnapps	Amber	Butterscotch	1.1225
Dekuyper White Cocoa	Clear	Chocolate	1.1204
Marie Brizard Green Crème de Menthe	Dark Green	Mint	1.1204
Marie Brizard White Crème de Menthe	Clear	Mint	1.1204
Dekuyper Cassis	Dark Red	Black Currant	1.1211
Hiram Walker Butterscotch Schnapps	Amber	Butterscotch	1.126
Galliano	Yellow	Vanilla Licorice	1.11
Dekuyper Thrilla Vanilla	Clear	French Vanilla	1.1193
Dekuyper Hot Damn	Red	Cinnamon	1.1191
Jägermeister	Black/Green	Herbal Bitter
Marie Brizard Parfait Amour	Purple	Vanilla Orange Almond	1.1163
Goldschlager	Clear w/ Gold Flakes	Cinnamon	1.1111
Dekuyper Strawberry Liqueur	Red	Strawberry	1.1005
Dekuyper Watermelon Pucker	Red	Watermelon	1.1051
Dekuyper Peachtree	Clear	Peach	1.1037
Dekuyper Mad Melon	Red	Watermelon	1.0971
Dekuyper Island Blue	Light Blue	Fruity	1.095
Dekuyper Apple Pucker	Lime Green	Sour Apple	1.0944
Dekuyper Cheri Beri Pucker	Red	Cherry	1.0937
Dekuyper Coconut Amaretto	Clear	Coconut Almond	1.0925
Grenadine	Red	Cherry/Pomegranate	Heavy