Hydrosols, fat washing, ‘rotovaps’: mixologists raid chemistry lab for flasks, evaporators and vacuum pumps to make cocktails at leading bars in India
- Using science-based techniques already adopted by some chefs, bartenders in upscale establishments in India are rewriting their cocktail lists
- From fat washing – infusing things like cheese in alcohol – to rotary evaporators, distillates and lactic fermentation, there’s no end to their inventiveness
It’s 6pm on a Friday and the bar at Home in New Delhi’s affluent Vasant Kunj district has already come alive with rotary evaporators, conical flasks, stirring rods, vacuum pumps, chillers and test tubes looking ripe for experiments.
The set-up seems right out of a chemistry lab, and head mixologist Santanu Chanda plays the role of chemist, working busily on a pink guava and hibiscus distillate.
The skin, leaf and fruit of pink guava is combined with hibiscus flower in the bulb of the rotary evaporator (or “rotovap”, as it is commonly referred to) along with vodka.
The temperature is set at 60 degrees Celsius (140 degrees Fahrenheit) and it spins at 100rpm (revolutions per minute). In under 45 minutes, the machine produces a crystal-clear liquid flavoured with sweet notes of guava and hibiscus.
The machine was imported from China about a year ago and has been an intriguing addition to Chanda’s workspace ever since.
“The idea was to bring innovation to Indian bars and introduce them to some of the modern techniques in mixology across the world,” says Chanda. “The machine is an excellent way to preserve the fresh, delicate flavours that would otherwise be lost if the ingredients were dried.”
Science laboratory equipment, such as rotovaps, have been used in high-end restaurant kitchens to extract flavours and aromas from food mixtures. However, now they are increasingly being used by bartenders to create cocktail components.
Another technique that employs a chemistry-lab-like technique is the creation of hydrosols, or “flower waters”, where the equipment used resembles a water distiller.
Plant material is boiled and simmered, and the resulting steam passes through a condensing tube. In this liquid, essential oils float to the top while the hydrosol that settles at the bottom is extracted.
Santosh Kukreti, head mixologist at Slink & Bardot, a kitchen and craft cocktail bar in Mumbai, uses this technique to extract essential oils and flavours to make bitters and spirits with ingredients including cinchona, licorice, gentian and citrus zest.
Similarly, Jishnu AJ, the head mixologist at Ekaa, a restaurant in Mumbai, uses this technique to create an edible calcium stone hydrosol that forms a part of his drink, Petrichor, to remind the drinker of the intoxicating smell that follows the first rains on dry earth.
“An increasing number of science-backed techniques are being used by mixologists to constantly present something new,” says Ajit Balgi, founder of The Happy High, a wine and spirits consulting and experiences company.
For instance, Kukreti uses clarification, a technique to create a completely clear drink by removing any solid components, to create a watermelon wine cocktail.
He prepares a mixture of watermelon juice and white wine, which is then clarified using a muslin cloth.
“We love to add a little twist to classic cocktails. One would expect the drink to be red; however, this crystal-clear bubbly bursting with flavours of watermelon adds a hint of surprise.”
Other cooking techniques are crossing over into the bar, too, such as fat washing, in which a high-fat ingredient is infused into a spirit and filtered through a funnel to get a clear liquid – a technique similar to enfleurage, used by perfumers to extract aromas from flowers and petals.
“It’s a great technique to add body and silky mouthfeel to a drink,” says Kukreti, whose fat-washed cocktail The Malty Dog combines single malt, rosso vermouth, truffle oil and raspberry.
In other fat-washed drinks, ingredients like coconut oil, truffle oil, cheese or even butter cookies are added to alcohol then frozen. The alcohol doesn’t freeze, but the fats in it turn into a granulate and are filtered out.
“Fat washing imparts umami flavours to the drink,” he adds.
Ashish Shah, head mixologist at the JW Marriott Hotel Pune, uses milk washing to add texture to a shaken drink.
Qilin is a milky white cocktail named after the goat in the Chinese zodiac. He adds milk to water and sugar, with a pinch of citric acid to break the milk into curds and whey. The mixture sits for 30 minutes, then is strained through a muslin cloth.
The final drink is decorated with golden foil, making it Instagrammable.
Sahil Essani, winner of Diageo Reserve World Class 2022 India, created vermouth fermented with quince, which won him the title in the national competition featuring the top 100 bartenders in the country.
Essani made the most of a process called lacto-fermentation, which he initiates with whey.
“Quince can be super astringent in its raw form, so I wanted to make it more nuanced,” he says. Chopped pieces of quince are added to whey, honey and salt and left to ferment for four days, after which it is juiced and clarified through a muslin cloth.
The leftover fermented brine is used to make spheres of agar that impart complexity to an otherwise dry martini.
Sous vide is a French cooking technique in which ingredients are vacuum sealed in a plastic bag and immersed in a temperature-controlled water bath to slowly and evenly cook while retaining moisture and concentrating flavour.
“I have been using sous vide to create cocktails because it’s one of my favourite machines to play with,” says Jishnu. He uses a sous vide machine to infuse gin with flavours.
Makrut lime and pandan leaves are sealed in a zip-lock bag with gin, then immersed in the hot water bath for 30 minutes.
“It is amazing to see the bridge between mixology and [the] culinary [sphere] shrinking. Techniques that were once restricted to the kitchen are now being adapted in the bar,” says Rohan Rege, winner of Diageo Reserve World Class India 2017 and runner-up in 2018.
The evolution of cocktail making
In India, cocktail drinking isn’t an entirely new phenomenon. The Stir Academy of Bartending, run by Shatbhi Basu, the first female bartender in India, was set up in 1997 as a platform for those interested in learning about bartending and getting trained.
“The past five years have seen the tipping point for the cocktail culture in India, with Indian bars featured in the top bars of the world. It is an exciting time for cocktails to trickle down to the urban masses,” says Balgi, who set up The Happy High in 2014 to train bartenders.
The growth of new Indian craft spirits has also provided a greater platform for mixologists to experiment and try new concoctions.
“Moreover, the big guns of the alcohol industry, like Diageo, William Grant and Pernod Ricard, have arrived in India,” says Pankaj Balachandran, co-founder of Tesouro by Firefly, currently ranked the best bar in India on the Asia’s 50 Best Bars list.
These brands brought in international talents to showcase what they have to offer, and Indian bartenders who are associated with the brands are learning from the best.
“There has never been a better time for bars in India,” Balachandran says. “These science-backed techniques have been doing the rounds for the past decade, but now they are becoming mainstream [in] bars in India.”