Salt—it's not just for margaritas any more. Bartenders have long understood that a few drops of bitters go a long way toward 'rounding out' the rough edges of a drink, and now they've figured out that a tiny amount of salt can create the same magic. Today, we look at some of the hows and whys as we explore how a few tiny grains can up the flavor of your favorite mixed drinks.
We first wrote about the trend toward salt-enhanced drinks here on Serious Eats over a year ago. Tracing the roots a bit further back, we know that the cult-classic cocktail book Beta Cocktails featured a cocktail calling for nothing more than Campari and salt back in 2010.
Here's where the lineage goes purebred: Alton Brown taught American men everywhere how to make coffee with salt in 2009. And Alton may have been inspired by the father of food science himself—Harold McGee.
And, of course bakers figured it out before bartenders. Those folks have long used salt to accompany caramel and chocolate, two ingredients known for their complex flavors, but also for their strong bitter components.
Wherever it started, the trend is clear: salt seems to blocks bitterness, which in turn ramps up the perception of other flavors.
A Tiny Pinch (or Drop) Goes a Long Way
Salt does it magic even when you can't taste it. The research shows that even subthreshold* levels of salt suppress bitterness.
What about salt and citrus? At subthreshold levels, the scientific literature suggests that salt might actually enhance the perception of sourness. Many mixologists agree, saying that a drop or two of saline "brightens" the flavor of a drink featuring citrus. The key here is a conservative dosage. Add too much salt to a drink and acidity will be suppressed.
*Subthreshold means that a flavor is present, but the majority of tasters would not identify the flavor.
Does Salt Really Act as a "Flavor Enhancer"?
The term "flavor enhancer" gets bandied about a lot with salt. It implies that salt makes meat taste more meaty, or grapefruit taste more grapefruity.
When I dug deep into the research on salt, however, there was no clear physiological link between salt and the enhancement of the other basic tastes. So what's really going on?
Here's one answer: we know that salt definitely does suppress bitterness, and bitterness in turn suppresses sweetness. By adding salt to something that's both bitter and sweet (like Campari), we intensify the sweet side of the liqueur.
There's another explanation as well: people still routinely report that salt enhances the flavor of foods, from the "pea-ness" of pea soup to the cheesiness of hard cheese. Here, the research isn't so conclusive about a physiological explanation, but it appears what's really being amplified is our perception of aroma.
One other element that isn't often discussed, but is especially relevant to the mouthfeel of mixed drinks is that the presence of salt in a drink, even in small quantities, will increase the flow of saliva in the mouth. The proteins in saliva will make any drink feel slightly more viscous or rich, which is generally a desirable attribute.
Not All Drinks Benefit from Salt
I've noticed in my own experiments that too much salt can have an overly suppressive effect on a drink, causing it to "pop" less. I was experimenting with simple homemade orgeat, a kind of almond syrup used in many classic cocktails, and found that if I started with an almond milk that contained too much sodium as a base, my finished Mai Tais lost a little of their pizzazz.
Lesson learned? Be aware of less-obvious sodium* sources and make sure to adjust added salt accordingly.
And here's one more thought: A few years ago I had a conversation with a friend who identified herself as a supertaster, which meant that she was especially sensitive to bitter tastes in alcohol. When I suggested that she add a few drops of saline solution to bitter liqueurs to help mask their flavor, she responded: "Oh, you don't understand, I drink Campari because it's bitter. I like bitter." When experimenting with adding salt to drinks, try it both ways, and decide for yourself which way is the most delicious.
*The research shows that it's the sodium side of the salt molecule (sodium chloride, or NaCl) responsible for suppressing bitterness.
How to Use Salt in Drinks at Home
To ensure consistent results, use a dropper bottle (old bitters bottles work well). I would also use a relatively weak saline solution of 1 part salt to 10 parts water (about 1/8 teaspoon table salt in 1 tablespoon of water) because you can always add more saline to a drink, but you can can't take it out once you've gone over the line.
Start with a single drop or two in citrus-based drinks; bitters-heavy drinks may require as many as ten drops, depending on your affinity for bitterness.
Have you tried any good drinks made with salt or saline solution lately? Tell us about them in the comments!
About the author: Kevin Liu likes to drink science and study cocktails. Wait, that's backward. Ask him geeky food and booze questions on twitter @kevinkliu. While you're at it, check out his book about cocktail science and his blog about food and science