Density is an important concept to understand when you are trying to figure out if something will float or sink, but it can also affect the gas in our atmosphere and even liquids in mixed drinks!
Layered drinks look very impressive, but it’s really simple science that makes it all possible. The layers are able to float on one another because of specific gravity. Specific gravity is the ratio between the density of a substance and a reference standard. Usually we use water as a standard for liquid, which has a specific gravity of 1.00. If oil has a specific gravity of 0.914 and we add it to water, it will float on the water because its specific gravity is less than that of water.
Photo courtesy of Pete: https://www.flickr.com/photos/comedynose/5297942291/in/photolist-ci5BKj-95akEB-CLDYxA-CTsQVA-xmijTt
The same concept can be applied to mixed drinks. In general, liquids with a higher sugar content like grenadine, liqueurs and brandies have a higher specific gravity, which means that they would sink in water. Liquids with higher alcohol content like vodka, absinthe and Everclear™ tend to have a lower specific gravity, which means they would float on water. In actuality, alcohol and water have the tendency to mix together, but alcohol can float on water if poured very carefully over the back of a spoon onto the water. Bartenders use the concept of density and specific gravity to create layered mixed drinks!
A simple layered drink to make is a Dark ‘n Stormy. There are only two ingredients, so it’s an easy one for a beginner.
1. Start with an old fashioned glass filled with ice.
2. Pour in about 4 fluid ounces of ginger beer.
3. Carefully pour in about 2 fluid ounces of dark rum. It may be easier to slowly pour it over the back of a spoon.
It is easier to make layered drinks containing alcohol because alcohol has a lower specific gravity than most liquids. If you are interested in non-alcoholic layered drink, consider making this fruity beverage!
1. Choose any glass you’d like. The narrower the better because you can see the layers better.
2. Start with a splash (or 2) of grenadine at the bottom.
3. Mix 1 part orange juice and 1 part pineapple juice together in a separate glass.
4. Carefully pour the orange-pineapple juice mixture over the back of a spoon onto the grenadine.
5. Then, enjoy!
These drinks look great without a lot of work. Just science! To see density in action, visit OKRA Charity Saloon on Cocktail Chemistry Mondays (September 19th) and vote for HMNS while you are there!