Whether you want to create layered shots like the B-52 or top a cocktail with a colorful float, it's important to know the density of the liquors you're pouring. Floating ingredients is a simple bartending technique that's used to create stunning drinks. In order to do it successfully, a specific gravity chart will help you understand the order in which you should pour the ingredients.

The History of Layered Drinks

Around the turn of the 20th century, beautiful pousse-cafés were created all over the world, especially in Europe. People enjoyed these captivating layers of spirits and syrups in their everyday lives.

The layered drinks could get quite extravagant. At times, drinkers would be treated to a pousse glass filled with 10 or more carefully layered ingredients. The trend was a passing fancy and pousse-cafes are rarely seen today.

The 1960s and '70s brought the technique back to life in the form of colorful layered shooters like the Irish flag and B-52. These fun, vivid shots remain a hit at parties and they are a fun way to show off your advanced bartending skills.

Beyond shot drinks, a number of cocktails are also layered. Sometimes, as in the Easter Bunny, it's to add a decadent and eye-catching layer on top. In other instances, high-proof rum is floated so it can be lit on fire, or beers of different densities are layered in drinks like the black and tan.

How to Layer Drinks Using Specific Gravity

The key to creating perfectly layered drinks is to pay attention to how heavy each ingredient is compared to the other ingredients. The weight of each liquid is measured by its specific gravity.

In the drink world, the density of water (with a specific gravity of 1.0) is compared to the liquid being measured to get its specific gravity.

For instance, a thick syrup like grenadine is very heavy and has a specific gravity of 1.18. That is why grenadine sinks when added to a tequila sunrise.

Likewise, most of the base distilled spirits that contain no sugar (e.g., gin, whiskey, etc.) are lighter than water and have a specific gravity somewhere around 0.95. This allows high-proof rums to float on top of drinks like the flaming Dr. Pepper when you want to light it on fire.

In order to create a layered drink, the heavier ingredient needs to be added to the glass first. More liquids are added in the order of their weight, with the lightest ingredient on top.

Tips The best layered drinks are poured over the back of a barspoon to restrict the flow so the ingredients will float instead of mix together.

Dairy cream is generally lighter than liquors and mixed drinks, so it's often floated on top of drinks, including the Irish coffee and candy corn shot. Heavy cream is preferred, though any cream with a milk fat above 30 percent will generally work. Sometimes it's helpful to lightly whip or shake the cream to add air so it floats better.

Specific Gravity Chart for Popular Liquors

General measurements are used for the specific gravity of various liquors and those are listed in the chart. This list includes common distilled spirits that are used in layered drinks. They are in order from lightest to heaviest as you work down the list.

Keep in mind that brands of the same style of liquor may vary in their specific gravity. For instance, most coffee liqueurs are lighter than Kahlua, which is the most popular brand of that flavor. While a drink may work with one brand, switching to another brand may not produce the same distinct layers.