Cocktail Queries: Why Do We Light Drinks on Fire? What Does it Do?

Cocktail Queries is a Paste series that examines and answers basic, common questions that drinkers may have about mixed drinks, cocktails and spirits. Check out every entry in the series to date.

The sight of a flaming cocktail is inseparable from the very idea of “cocktail culture,” but beyond the dazzling spectacle it achieves, it’s only natural to ask: Why do we do it? Why do we engage in this particular step, given that it’s unnecessary to creating cocktails, which are typically served ice cold? Does the act of lighting your drink on fire fundamentally change its flavor profile? Are there some drinks where flaming alcohol is truly essential? We’ll do our best to explain.

Flaming cocktails have been a mainstay of the American bar scene as far back as the 1860s at least, which we know from the primary source of the first-ever bartender’s manual, Jerry Thomas’ How to Mix Drinks. This manual is considered the foundational text of cocktail culture itself, and it contains the first recipe for the Blue Blazer, one of Thomas’ signature drinks. It’s a simple drink, but a very impressive sight: Strong scotch whisky is mixed with boiling water and set on fire, and then passed between two glasses back and forth via careful pouring to create “the appearance of a continued stream of liquid fire.” The flames are then extinguished, and the drink is completed with a small amount of sugar and lemon peel. It’s more or less like a hot toddy with scotch.

The Blue Blazer recipe is also indicative of the science behind flaming drinks, which largely relates to the temperature and relative strength of an alcohol-water mixture. Ethanol is fairly combustible, but for it to light on fire, it’s not always as simple as simply touching a flame to its surface. Rather, the liquid must reach a temperature where combustion is possible—a flash point. This flash point gets lower, the stronger an ethanol-water solution gets. For instance, standard 80-proof spirits such as whiskey or vodka have a flash point around 71 degrees Fahrenheit—they may need to be heated slightly in order to combust, especially in a cold drink, and are easier to put out. Overproof spirits, on the other hand, such as 151-proof rums or 190 proof Everclear are combustible at lower temperatures, with Everclear possessing a flashpoint around 56 degrees Fahrenheit. That makes them much easier to light, and much more steady in their burning.

Traditionally, bartenders take advantage of this property in order to present a flaming flourish in the form of floaters of high-proof liquor atop otherwise prepared cocktails. A small floater of 151-proof rum or neutral grain spirits can be ignited easily and burns off quickly, achieving a flashy effect without really changing the drink itself very much.

This begs the question: Is lighting a drink on fire solely a matter of aesthetic presentation? And in most cases, the answer is “yeah, pretty much.” This is true, at least, for the majority of flaming drinks that are given tiny floaters that are allowed to quickly burn off. There are some exceptions, however, where setting the drink on fire is thought to contribute more strongly to the actual flavor profile of the beverage.

One of these drinks would be the popular Flaming Dr. Pepper, in which a shot glass of amaretto and 151-proof rum is set on fire, before being dropped into a mug of light lager or pilsner beer to create a drink that is said to replicate the spicy profile of Dr. Pepper soda. Here, fire is being used to reduce the amaretto and rum slightly, concentrating those flavors before they’re mixed in with the beer. It’s a classic of the “bomb” school of cocktail shooters.

In other applications, meanwhile, a flaming alcohol may be used as a way to interact with/modify a drink’s garnishes, as in the Spanish Coffee. In that drink, a glass is coated on its rim with sugar, and then flaming overproof rum is used to caramelize that sugar, contributing more of a creme bruleed quality to the finished drink. It’s a creative way to incorporate fire in a way that is for more than just show. The same is true of flaming liquor used to do things like ignite a citrus peel, or toast whole spices like a cinnamon stick.

If all this talk of fire is making you want to try your hand at lighting your own drinks, however, there’s something else you should consider. The dirty little secret of flaming restaurant/bar cocktails is that they’re often being made in an entirely different manner than attempts to replicate those drinks at home. As demonstrated by the invaluable rum resource/alcohol blog Cocktail Wonk, although fire and tiki cocktails in particular tend to go hand in hand, the impressive flames above your fiery zombie or mai tai are rarely the result of ignited rum or Everclear. The reason why is simple: The small blue flames created by burning ethanol aren’t particularly impressive, and can be difficult to even see in a well-lit room.

More impressive, larger, yellow-colored flames that are easier to see are instead produced in many bar settings through the use of ignited lemon extract, which is used to soak a sugar cube or bread cube, placed in a hollowed out citrus hull atop your drink. The key here is both lemon extract’s alcoholic strength—around 170 proof—and its oil content, which creates a much brighter and more vigorous flame. That flame can then be made even bigger by a tiki bartender employing such tricks as cinnamon powder, which ignites into an impressive fireball when sprinkled above a flaming drink, which is just as dangerous as it sounds.

The bottom line is that lighting a drink on fire is often a purely aesthetic choice, but it’s also capable of being an important aspect of that drink’s flavor profile. With that said, it’s a practice that is almost certainly best left in the hands of professionals.

Jim Vorel is a Paste staff writer and resident liquor geek. You can follow him on Twitter for more drink writing.