layering is a technique that produces a colorful, rainbow-like effect in a tall cocktail or shooter glass. Shooters like the Pousse Café and B-52 are classic examples of this technique, but almost any drink can be layered. See Pousse Café.
Layering exploits the varying densities or specific gravities and viscosities of the liquids, which generally depend on their sugar, alcohol, and water content, with the sweetest liqueurs being the densest (heavy cream, a common Pousse Café ingredient, is a special case). The denser liquids will sink to the bottom of the glass while the lighter liquids float on top. Distilled spirits with no added sugar, such as brandy and vodka, have the lowest density because of their high alcohol content; this makes them prone to miscibility and difficult to layer, and they are generally reserved for use as the top layer. Sweetened spirits—liqueurs and cordials—as a category have widely varying sugar levels, which makes them ideal for layering.
There are multiple ways to layer a drink, with some methods calling for the liqueurs to be poured over the back of a spoon and down the wall of the glass, starting with the densest liquid first. Other methods start by pouring the lightest elements first and then streaming the next densest liquid down the middle of the layers, sometimes with the help of special gadgets; this effectively pushes the other liquids on top. Both methods work well and produce visually appealing drinks.
See also Pousse Café and shooter.
Regan, Gary. The Joy of Mixology. New York: Clarkson Potter, 2003.
By: Darcy O’Neil