13 Oct Citrus: A Saint in Distilling and Bartending Both

It’s the not so silent hero of so many of our favorite drinks, dishes, and desserts, but why does citrus pack such a punch? Find out.

Okay, picture this: you’re slow-braising some gorgeous chicken thighs (skin very much on). After having the thighs marinate overnight, you transfer those leggies into a stockpot, browning each side, and then proceed to make a sauce by pouring in some thick and flavorful chicken stock leftover from a whole bird you made last week and a handful of spices. After bubbling for a few minutes, you taste the contents of the stockpot and see that there’s a secret ingredient missing, one that brightens every dish, forcing the existing flavors into stark relief, and no it’s not salt (though that’s very important too)—it’s CITRUS! The hero for bartending, distilling, and baking alike (alongside cooking), citrus is such a key component in our food and drink. But why is that? The short answer: science. (Bar science to be exact.)

Citrus fruits are by their very nature pleasantly aromatic and antibacterial, so their inclusion into the process of bartending helps to both bring out flavor and extend the shelf life of certain concoctions. The anatomy of citrus fruit involves an epidermis, or outermost layer, followed by the flavedo, which is the subepidermal region of the peel that contains pigments colored either yellow, orange, or green, depending on the variety. This is also where the oil glands in citrus reside. Under the flavedo is the albedo, which separates the peel from the rind, and then deeper into the fruit we find the carpel, which is filled with juice sacks. The areas most commonly used for their aromatic and flavor properties are the flavedo and the carpel. The juice can be extracted from the segments in the carpel and is essential to a plethora of bartending staples, from a Bee’s Knees to a Corpse Reviver No. 2 to one of my personal favorites, the Daiquiri. What would these cocktails be without their fresh citrus juice additions? Not that good honestly!

There are other ways that drink makers can involve citrus in their mixing, one of which is by using spirits that have a strong citrus character. This is where distilling companies like ours come in. 

The process of capturing the essence of citrus through distilling is no walk in the park, though I’d say it’s easier than capturing flavors such as fresh apple or pear (respect to our eau de vie/brandy brethren out there). There are a couple of ways that you can go about accessing that flavor. For both our 1643 Gin (the citrus suppler for which I wrote about in more detail) and Lafcadio Rum, we chose to use the flavedo, which is where the many slightly brittle oil glands in citrus fruit reside. We isolated the oil by carefully peeling a metric shit ton of lemons and oranges (that is an exaggeration, but it was a lot of peeling.)

This peeling process is not the same as the one you see when you sit at a bar and order a drink that involves a citrus peel garnish. While the bartender in this scenario will try to take a good amount of the pith, or that slightly spongy white stuff below the surface of the outer layer, off when they’re peeling so as to have extra structure for the garnish, we as distillers want as little of the pith as possible. Inside the pith are compounds that, when distilled, impart a bitter flavor that can be offputting in the final beverage, so when we’re peeling we’re trying to scrape off just the flavedo and little else. (I, Devon, remain the peeling queen and will accept any challengers for the title.)

We opted to use fresh lemon and orange peel when distilling both our gin and our rum because we had access to incredible citrus fruits, but other distillers might choose to use dried peel or artificial flavors in their distillations. Some even work with the juice of the citrus, though I’d say that’s a little less common. What you have at the end of the process, however, is citrus flavor in a very stable format that’s an excellent addition to your bartending toolbelt. Unfortunately, all the fresh juice that bartenders typically prep at the beginning of their shift isn’t very stable and will have to be thrown out in a matter of days, but working with citrus flavor in a spirit or liqueur allows them to have a product with that kicky citrus character that is shelf-stable for months. Cocktails that take advantage include a Negroni, a Green Swizzle, and in our opinion, the best variations on a gin & tonic.

So what’s at work when we’re drinking something with excellent citrus character?

We all know that flavor is not one-note, nor does its perception come from a single sense. “Flavor perception is quintessentially multisensory, the result of a cascade of processes that operate on sensory signals arising from the activation of multiple sensory modalities, including (retronasal) olfaction and somatosensation as well as gustation” (Veldhuizen et al, 2018). A cascade! I love the language. When we bite into a lemon or sip pure lemon juice (something we all do all the time, right?), we perceive that classic sour-citrus flavor in a way that is patently overwhelming. Molecules within the lemon or the juice retronasally activate olfactory receptors, or those relating to smell, which conveys that distinctive citrus flavor, but lemon also contains sugars and citric acid, flavorants that are gustatory, or concerned with taste, the latter of which contributes the sour quality.

The thing to keep in mind as I rattle on here is that all these elements are working in tandem. For instance, the sugar content in lemon (2.5% of the juice) would be readily perceived as sweet when dissolved in water but is hardly able to contribute a detectable sweet gustatory quality because the citrus acid masks it (Veldhuizen et al, 2018). Evidence shows that the minor inclusion of lemon often enhances the sweetness in a dish, bringing the flavor out. Evidence also suggests that interactions between the olfactory and the gustatory take place in both directions, meaning that gustatory flavorants enhance olfactory responses and vice versa, so when in doubt, whether your distilling a new spirit or working on your home bartending, reach for something with citrus if you feel like your drink is missing a bit of that je ne sais quoi.

References:

Maria G Veldhuizen, Ashik Siddique, Sage Rosenthal, Lawrence E Marks, Interactions of Lemon, Sucrose and Citric Acid in Enhancing Citrus, Sweet and Sour Flavors, Chemical Senses, Volume 43, Issue 1, January 2018, Pages 17–26, https://doi.org/10.1093/chemse/bjx063