Restaurant kitchens have long gone gaga over the process known as sous vide, and home chefs are increasingly using the technique to turn out perfectly cooked meals. But sous vide’s benefits aren’t limited to the dinner plate, and many bartenders are applying the process to preparing syrups, infusions and other cocktail ingredients, with excellent results.
“Sous vide” simply means “under vacuum” and is a cooking process in which foods or liquids are placed in a package (typically a plastic sheath, a canning jar or an ordinary zip-sealed plastic bag) from which all air is then removed. The sealed package is then immersed in a circulating water bath held at a precise temperature (the descriptively named “immersion circulator” is the tool that makes all this possible). Preparation temperatures are typically much lower, and cooking times much longer, than those used in traditional cooking, but the steady application of heat to ingredients held in a vacuum-sealed container translates into a more precise, delicate preparation, full of flavor and without the loss from evaporation or the compromising character of oxidation.
“Making flavored syrups [using sous vide] gets such a purity of flavor, and is much more consistent,” says bartender Naren Young. Young is the co-owner of Dante in New York City and has used sous vide to prepare fruit syrups and to infuse entire cocktails, such as a Negroni flavored with lemongrass, lavender or sandalwood. “I like to infuse a big batch at a time so you have enough for an entire month,” he says. “Plus, it makes for a quick-and-easy serve because it’s just a one bottle pick-up. Stir it down and it’s ready to go. Too easy!”
Early sous-vide equipment was designed for big restaurant kitchens, with big restaurant budgets footing the bill. But cheaper commercial equipment, along with models made for home use, are quickly leveling the playing field, with most home devices priced below $200 (and some below $100). ChefSteps recently debuted the Joule immersion circulator, a small-and-sturdy device operated via a tablet or smartphone app (and voice-activation enabled via Amazon Alexa). Joule joins other sous-vide players including Anova and Sansaire, which helped pioneer the use of immersion circulators among home cooks. These household devices are about the same size as a rolling pin, and can be used with most cooking pots.
At the recently opened No Anchor in Seattle, owner Chris Elford uses the tool to prepare the bar’s Stone Fury Julep. Using equipment already running in the bar’s kitchen, Elford slow-cooks grilled peaches or nectarines sous vide until they’re so tender they fall apart, becoming the sweetener to the drink—attempting the same process purely through grilling would render the fruit too acrid to use. The liquefied fruit is then combined with a blend of whiskies (infused with mint via sous vide) and barley tea syrup to make a bottled cocktail that’s simply mixed with crushed ice to serve.
Sous Vide Everyday
Bartender Alex Day, who is a partner in bars including New York City’s Death & Co., as well as Honeycut, Normandie Club and Walker Inn in Los Angeles, says immersion circulators are essential tools at each of his bars. “What we’re doing with immersion circulators and water baths is applying very controlled and precise heating,” he says. “That allows us to extract flavor in more focused ways than we’ve been able to do before.”
Day adds that what started with simple tinkering out of curiosity quickly changed the way he thought about preparing cocktail ingredients. “At first, I was excited about speeding up the process of making, say, bitters—where you have dry, dense ingredients that you have to macerate for a long time to get the right extraction,” he says. “But we found you could seal that up in a bag, and in four hours or so have the same result that otherwise took weeks of soaking. And we found there’s a different flavor coming out—in the time it takes for a slow maceration of dried orange peel, you get different flavors than you do in a short, precise extraction.”
After a lot of experimentation, Day says two camps presented themselves—in one were dense, dried ingredients such as barks and dried herbs, that required the application of higher heat but still below the threshold that converts sugars to inverts. In the second camp were more delicate ingredients such as berries and other fruits, that would contribute very delicate, bright flavors without acquiring a jammy, “cooked” character under application of lower heat. “When you put the ingredients in a bag and seal it, you can totally control every aspect of it,” Day says. “You don’t have to worry about evaporation and oxidation, and the way those affect flavor. You can seal bourbon and coconut flakes and put it under heat, without concentration or oxidation, and we can extract the flavor very quickly. We then throw it into an ice bath to shock it back into solution, and the whole thing was such a revelation.”
Templates to Try
Day says that each new project requires a bit of fine-tuning, but several rule-of-thumb templates have been adopted. Note that regardless of the approach, it’s important that as much air as possible be removed from the preparation bag or container. For best results, either package the ingredients using a vacuum-sealing device, or use the “water-displacement method”: place the ingredients in a zip-close plastic bag, then seal all but 1 inch of the zip-closure. Slowly immerse the bag in a pot of water while holding the small opening just above the water’s surface, until the pressure of the water forces all air out through the opening; completely seal the bag before proceeding.
Delicate Fruit Syrups
Raspberries, blackberries and other delicate fruits require a gentle touch, but can offer up a flavor akin to biting into a fresh berry with each sip of a cocktail. Using a 1:1 simple syrup as a base, measure out a desired quantity of syrup into a zip-closed plastic bag; add raspberries or other fruit to the syrup (Day recommends starting with a 1:10 ratio of fruit to syrup—for example, 1 ounce of fruit for 10 ounces of syrup) and seal the bag as described above. Preheat a water bath to 135 degrees Fahrenheit and add the prepared bag to the water; cook for 2 hours, then plunge bag into an ice bath to shock the syrup and arrest the cooking. Strain syrup and keep refrigerated for up to 1 week.
“Another thing that’s really cool with syrups is using a base liquid made up of some flavorful juice,” Day says. “One of my favorites is citrus syrups or cordials. If you’ve ever scraped your nail across the skin of a Meyer lemon, it has such a beautiful fragrance—you have that translating over into the liquid, which we can use in syrups, sodas, whatever we want.”
To prepare, use a zester or vegetable peeler to remove the zest from the desired number of citrus fruits (grapefruit is a perennial favorite, and in winter’s citrus season, reach for Meyer lemons, mandarin oranges, or any other favorite citrus). Add the zest to a zip-close plastic bag and juice the zested fruit. Measure the amount of juice using a kitchen scale, and combine the juice with an equal amount of sugar in a blender, then blend until the sugar is dissolved. Add the syrup to the bag of zest, seal according to directions, and place in a 135 degree Fahrenheit water bath for 2 hours. Plunge bag into an ice bath to cool, then strain before use. Keep refrigerated and use within 2 weeks. “It’s not a terribly hot bath,” Day says. “We find it maintains the vibrancy of the citrus, and integrates the spectrum of the fruit’s favor in a delicious way.” Better yet, the cooking process breaks down the fruit’s particles, resulting in a clear syrup that can be carbonated without the need for additional clarification.
“For coconut, cinnamon bark, dried spices, dried citrus peels, and other hard ingredients, we often cook at 145 degrees Fahrenheit as our starting point,” Day says, noting that some hard-to-extract ingredients may require temperatures as high as 155 Fahrenheit (and two hours is typically a good starting point for the cook).
In addition to simple flavor extraction, Day says immersion circulators can speed up the dissolution of ingredients that normally take a long time to fully integrate, such as gum Arabic when making gomme syrup. “Traditionally, you add the gum arabic very slowly into the mixture, and that can take a day for the syrup to clarify,” he says. “But we can take 2:1 demerara syrup, add a bit of gum Arabic [about 6 percent of the mixture, so 100 grams of syrup would require 6 grams of gum Arabic], cook it at 145 degrees Fahrenheit for about 2 hours, and it integrates very quickly.”
Having that process in hand opens the door to adding delicate flavors such as pineapple to the gomme syrup. For the pineapple gomme used at Honeycut, Day combines equal parts pineapple juice and sugar in a blender, then blends to dissolve the sugar, and combines the syrup in a bag with 3 percent gum Arabic (3 grams of gum Arabic to every 100 grams of syrup—pineapple’s high pectin content requires less of the emulsifier). Sous vide at 145 degrees for two hours, and the result is a lush, velvety syrup with the brightness of fresh pineapple.
“We’ve all been taught that alcohol boils at 173 degrees Fahrenheit at sea level,” Day says. “But the reality of the chemical reaction is as soon as you apply heat, you have evaporation. Even at room temperature, you have evaporation—heat just speeds up that process.” Day notes that if any air remains in the bag, it provides space for expanding alcohol vapors to occupy, and for oxidation to take place—this becomes immediately apparent during the cook, when the bag will expand like a balloon (and possibly pop), and the finished mix will have a compromised flavor. To be on the safe side, take care when vacuum-sealing the bag (or when using the water displacement method) that all air is removed, and keep the temperature setting safely below 173 degrees Fahrenheit—as Day notes, there’s rarely reason to heat above 155 for cocktail ingredients, anyway.
No Quick Fix
While sous vide can cover many bar-ingredient bases, it’s not a silver bullet—there are some preparations that simply taste better when made in a traditional fashion. Ingredients that rarely perform well in a sous vide preparation include delicate produce such as cucumbers, and many fresh herbs, which can leach chlorophyll and bitter flavors along with the desired properties.
Day notes that his colleague Devon Tarby prepares a vodka infused with roasted garlic and black peppercorns for use in Bloody Marys—but a sous vide experiment resulted in unpleasant, over-extracted flavors. “But let it sit overnight, and it’s gorgeous,” he says. “There are some cases where the traditional method produces a better result.”
Day adds that the barrier to entry for experimenting with sous vide continues to drop. Restaurant equipment may be needed for high-volume operations or heavy day-to-day use, but for many professional and home bartenders wishing to make small batches of syrups or infusions, a simple household immersion circulator and some zip-sealed bags and canning jars puts the practice within easy reach. “You’re working with alcohol, sugar and resilient ingredients,” he says. “It’s one of the reasons I like to put it out there as an option for bartenders—it opens the door to flavors we didn’t have access to, for a budget anyone can afford.”