While there is an exception to every rule, most bartenders recognize that there are really two types of cocktails: sours and bitters. These flavors temper the taste of alcohol, as most people don’t enjoy straight 40% alcohol booze. The first thing bartenders can do to give their drinks flavor – the first step in creating the perfect cocktail – is to add a source of sugar, often in the form of simple syrup (just sugar and water) or vermouth. However, a drink with just booze and sugar would taste cloyingly sweet to most people, so bartenders often add something else to counteract the sweetness, and this is where the two families of drinks now diverge into bitters or sours. For bitters, you might add angostura or a bitter liqueur like Campari. But in this post, I’ll focus on sours, where the choice is lemon or lime juice, which offer strong sources of acidity. The acidity and sugar together help cut the otherwise overpowering rocket fuel taste of booze. These flavors are so ingrained in mixology that many cocktail recipes are built from well-known industry ratios.
In my last blog post, I used a rye manhattan as a model for improving the taste of your cocktails, but here, to understand how all the flavors of a cocktail fit together to make the perfect cocktail, we will examine the true backbone of many cocktails, the “daiquiri spec.”
Daiquiri Example Recipe:
2 oz white rum
¾ oz simple syrup
¾ oz lime juice
As you can see, the ratio in this drink is 2:¾:¾ (booze:simple:lime). This ratio is critical to the quality of a cocktail, but there are many ways to play around and customize the individual components to create new flavors. You can swap the booze around (say, mezcal instead of rum), as well as the simple syrup (switch it out for honey syrup) and the acid (choose lemon juice over lime) and, using the same ratio, make something that should taste pretty good (as long as the flavors “mesh”).
This ratio makes for a pretty strong drink and works great for bartenders and the booze-tolerant among us (after all, most people don’t sip liquor by itself, or “neat,” I remind myself). But for more mass appeal, bartenders often shift the ratio to 2:1:1. This upped sweetness and acidity helps cut the bite of the booze more, which is great for people who really “don’t want to taste the booze at all!” We know that 2:1:1 tastes good for many people, which is great qualitative proof that this ratio is the way to go. Since this is a science blog though, let’s do some math and figure out exactly what makes up these drinks.
After accounting for diluting and chilling our drinks, we can calculate the amounts of booze/sugar/acid in our drink with a 2:1:1 ingredient ratio. This will give a foundation for what is the basis of many cocktails. To do this, I need to define a couple terms that describe the components in our drink: booze, sugar, and acid. Booze is easy – it’s the percentage of alcohol in our cocktail. Sugar is slightly more complicated: the ‘sugariness of solution’ is measured in Brix, where 1° degree Brix corresponds to one gram sucrose in 100 grams solution (basically one percent sugar by weight). As an example, the sweetener I’ve been describing is simple syrup, which is made with equal parts (by weight) sugar and water, i.e. 100 grams of sugar dissolved in 100 grams of water. Therefore, our simple syrup is a 50° Brix solution (100 grams sugar in a total of 200 grams solution).
The final component of our cocktail is acid. Up until now I’ve been using lemon/lime, which are roughly six percent acid, meaning there are six grams of acid in 100 milliliters of fruit juice. Almost all the acid in a lemon is citric acid, so it is basically a six percent citric acid solution. Lime is more complex. It is roughly four percent citric acid and two percent malic acid (adding up to six percent acid overall), while it has many trace acids, too.
I did the math for a 2:1:1 drink so you didn’t have to. Taking all of this together, the backbone of many sour cocktails is a solution that is cold, 16% alcohol, about 12° Brix, and 1.2% acid.
Now that I’ve done all this fancy math, how can I use this information to make delicious cocktails? To answer that question, let’s go back to the components of the drink before I chilled it and diluted it. As a reminder, I started with two ounces of 40% alcohol, one ounce of 50° Brix solution, and one ounce 6% acid solution.
From here, we can start having fun and replace these component solutions. Booze is fairly easy to change out (for example, use gin instead of rum, making a gimlet), but changing the sugar/acid components will require a little bit more finesse.
Let’s start with the sweetener.
Brix Adjustment: I derived some equations that allow you to adjust the sweetness of a solution up to a 1:1 or 2:1 simple, calculating the grams of sucrose to add in, given the current Brix of the solution. Up until now I’ve been describing an equal-parts-by-weight, 50° Brix simple syrup. One easy way to change this up is to make this syrup using brown sugar. But why stop there? If our goal is a 50° Brix solution to use in mixing a cocktail, we should be able to use whatever liquid we want and adjust the sugar content up to 50° Brix.
For example, we could use pineapple juice, which is roughly 15° Brix on average (see Table 1). However, we want a solution that is 50° Brix to use in our cocktails, so we need to add sugar to our pineapple juice. The question is how much, and again I did some math so you don’t have to. First, multiply your starting Brix (in this case 15) by two, and subtract it from 100 (100-15 x 2=70). The solution this equation is the number of grams of sucrose you have to add to 100 grams of juice to adjust it up to 50° Brix (so add 70g sucrose to 100g juice). Now, just use your sweetened pineapple juice (which is delicious, by the way) instead of simple syrup in your recipes. You can use this formula to make any obscure liquid you find into a fancy simple syrup.
Adjusting your acid
In addition to adjusting the sugar content, you can also adjust the acid content of a solution by replacing lime/lemon juice in recipes.
For example, let’s say you wanted to use relatively bland pomegranate juice instead of lime juice in a margarita. If you substituted it without altering it, the drink would have no sharpness or acidity to it, and you’d be disappointed by the taste. If you want that pomegranate flavor to pop out, you can adjust the acid level of the juice to match the level you would get from lime. As briefly mentioned above, lime juice has four grams citric acid and two grams malic acid per 100 milliliters, totaling six grams acid per 100 milliliters (six percent acid). To attain the same level of acidity, you can purchase food-grade citric and malic acids cheaply on Amazon (one kilogram bags will last you forever and run about 20 bucks at most), and with a kitchen scale, you can adjust the acid concentration of any juice.
Pomegranate isn’t very acidic (less than one percent), so we’ll ignore the acid that’s in it. The acid levels of various juices are in Table 1, and usually you want to adjust to the acidity of lemon/lime. With pomegranates, we can add four grams of citric acid and two grams of malic acid into every 100 milliliters of pomegranate juice we want to use. Once we shake it up and dissolve it, we have a juice that can be substituted for lemon/lime and give us our desired flavor.
With the knowledge of basic cocktail anatomy and an understanding of how to make custom simple syrups and acids, go forth and experiment! Throw two ounces mezcal into a shaker with one ounce sweetened pineapple and one ounce acid-adjusted watermelon juice. Or use acidified orange juice instead of lime to make a breakfast margarita. You can add sugar and acid to pretty much anything, so follow your taste buds and go wild.
For more information check out Dave Arnold’s book Liquid Intelligence as it goes in depth on this and a variety of other techniques. Also, his new bar “Existing Conditions” in the East Village of Manhattan is worth a visit (or many).
Dan fills his days pursuing a PhD in Neurobiology, and by night conducts experiments with different drink recipes and techniques. For that, his wife and friends are sometimes thankful.