While at Drink a few months ago one of the lovely bartenders was running through the ingredients in one of their tiki drinks, the Jet Pilot I believe. The usual suspects were there, with a twist provided by the inclusion of cinnamon syrup. While the spiciness of the cinnamon proved a nice addition to the drink, I couldn't help but ponder the use of syrup to draw out that flavor. Was the sugar necessary for extracting the flavor? Was there hope for combining cinnamon with sweet spirits?
Over the next few months I became more aware of the ubiquity of flavored syrups. New recipes were dense with the stuff and it seemed as if syrups were quickly becoming the default when a bartender wanted to introduce new flavors. Why was such a popular technique bothering me so much?
Because scientifically the sugar is inconsequential. The water acts as the solvent, if anything the highly hydroscopic sugar would reduce the effectiveness of the water to dissolve flavors into solution. Infused water alone (possibly heated to increase the solubility of any flavors compounds) should provide as much, if not more, flavor without limited the potential applications; the flavored syrups could be recreated on the fly with the addition of simple or demerara syrups bases.
Flavored waters, however, are not without their own flaws. All of that liquid risks diluted drinks, forcing a compromise between the strength of the additional flavor and those already present in the base spirits. What we'd need is a more powerful solvent, something that can extract the desired flavors in much smaller quantities.
That solvent already plays a critical role in the world of mixology, extracting the essence of berries and herbs into gin and caramelized wood into whiskey to name a few. Alcohol, of course, is the prized solvent. Infusing herbs or spices in relatively bland high proof spirits such as vodka or 151 produces solutions so potent that only a few drops are necessary to impart the desired flavor to a drink. Pretty much bitters without the bitter.
To demonstrate the above arguments I put together a test with kaffir lime leaf. Each infusion placed the same amount of chiffonade'd leaves into one of four solvents: (from left to right) 151 rum, water that was them simmered with the leaves, a simple syrup simmered with the leaves, and room temperature water.
The power of the alcohol is immediately visible in the vibrant green of the 151 infusion, and the taste proves no exception. What flavor dissolved into the syrup is, as expected, dominated by the sweetness. With no completing flavors, the kaffir comes through more clearly in the simmered water, although its not entirely welcome; it seems that many of the bitter compounds in the leaves dissolve readily in the heated water, creating a rather unappealing infusion. The unheated water offered hints of flavor but nothing noteworthy.
As academic as this has been, it has proven tremendously useful at least once.
One of my favorite hidden jewels, The Tequila Book (Gorman and de Alba, 1978) compiles a myriad of tequila recipes ranging from offensive shooters to classically designed cocktails featuring everything from orange bitters to egg whites (just imagine how refreshing this can be after reading through every vintage text without seeing one good tequila drink). A particularly intriguing entry, the Spanish Fly called for tequila, Liqueur 43, and a sprinkling of cinnamon. The agave of the tequila and vanilla of the Liqueur 43 would pair great with the cinnamon, but the ground spice would just clump on the surface of the drink and offer little aside from aroma.
With the inherent sweetness of the Liqueur 43, a syrup would be immediately out of the question. Following the arguments above, I procured cinnamon extract, readily available in the baking aisle of any grocery store, and went to work. Indeed, the spicy extract did the trick, providing all of the cinnamon flavor without any unnecessary sweetness or dilution.
2 oz reposado tequila
1 oz Liqueur 43
0.25 oz Benedictine
0.25 tsp cinnamon extract
dash xocolatl mole bitters
A lesson I won't soon forget.