BLUE HAS SOLD A LOT OF GIN

BLUE

HAS SOLD A LOT

OF GIN.

Interest in gin colored with butterfly pea flower has shown an impressive durability.

WRITTEN BY AARON KNOLL

Proclaiming a “New Blue Spirit,” a 1991 Sunday Times advertorial proclaimed, “The launch of Bombay Sapphire, a high-strength gin in a startling blue bottle, aims to convert British G&T drinkers to the concept of designer gin.”1 This “game-changing” blue bottle was credited with fuelling the gin renaissance.2 Over a decade later, spirits importer Michel Roux told the Wall Street Journal, “We are certainly counting very much on the reaction of the blue color,” to justify the post-distillation infusion of iris to give Magellan Gin a distinctive blue hue.3

But now what’s blue doesn’t stay blue.

Today, the new blue changes colors. Thanks to the peculiar properties of the butterfly pea flower, these gins are a deep

1 The Sunday Times 1991. 2 Knowles 2013.

3 Lawton 2003. shade of blue in the bottle. Once mixed with an acidic ingredient like lemon juice or tonic water, it turns pink.

Pioneered by the Australian-based Husk Farm Distillery with their Ink Gin, launched in 2015,4 the trick has often been copied. Distillers the world over have released gins colored with butterfly pea flower. Some of these gins have quickly become big sellers. Canada-based Victoria Distillers’ Empress 1908 Gin rapidly caught on in some markets, to the point where it only trailed Hendrick’s in terms of premium gin brand sales,5 selling over 7,000 cases per month.6

United States producers; however, largely sat out this trend due to regulatory hurdles. That may be set to change. In October

4 Scenery 2015; Brennan 2016. 5 Freeman 2017.

6 Guilfoyle 2020. 2021, the FDA approved “aqueous extract of butterfly pea flower (Clitoria ternatea) as a color additive in various food categories,” including alcoholic beverages.7

While the initial novelty of color-changing gin may have worn off, they’ve shown an impressive durability. Buoyed by the success of Empress 1908, interest remains and these “blue” hued gins are still piquing consumer interest behind bars and on store shelves. They’ve proven to be a reliable product expansion for some smaller distillers, like Nova Scotia’s Compass Distillers who are on their 27th batch of Gin Royal in only two years on the market.

7 United States, Food and Drug Administration 2022.

WHAT is BUTTERFLY PEA FLOWER

Butterfly Pea

Clitoria ternatea

A food coloring derived from cabbage, for example, is pinkish-red at the acidic end of the scale; green on the basic end of the scale, and roughly colorless at neutral. Butterfly pea flower is the most pH sensitive of these colorings. It changes color not just based on whether it is acidic or alkaline, but the intensity of the acid. At pH 2 it’s red, violet between pH 4 and 6; and then blue at pH 7.12 WORKING with BUTTERFLY PEA FLOWERS

“What's really neat is when you are working with it, the color change starts to happen immediately...and it looks really cool,” Alex Wrathell, head distiller at Compass Distillers says with a smile. “You just kind of see these rich blue lines, seeping down from the flowers.” The Halifax, Nova Scotia distillery, similar to many other creators of color-changing gin, achieves the effect through maceration. Their process starts by proofing the gin. The flowers are added to an infusion bag, the type brewers often use for hops, and placed right in the gin, for a “few days, typically.”

However, a careful balance drives decisions about how long the steeping lasts. Wrathell describes the challenge, to “...maximize the amount of coloration you get, because it will fade in the bottle over time, so you’re trying to prolong the duration of rich color you get in the bottle…without detracting from the taste of the base gin.” He adds, 12 Rawdkuen 2020.

The butterfly pea or Red Sweet Potato Asian pigeonwing (Clitoria Ipomoea batatas ternatea L.) is a widely naturalized perennial herb grown for its use in food. Mangosteen (husks, peels)The edible flowers are the Garcinia source of the blue hue; how- mangostana ever, in Thailand the leaves of the plant may be fried, IMAGE ADAPTED FROM: Rawdkuen, Saroat, et al. “Application of anthocyanin as a color indicator in gelatin films.” Food Bioscience 36 (2020): 100603. while the young seed pods are eaten as a vegetable.

The plant thrives in the tropics but can toler“If it’s infused for too long, it sorta starts to ate light frost, short-term flooding, and a wide take on a bit of this grassy, vegetal character range of soil pH’s. Its relative hardiness has from the flowers.” He describes it as “minor,” led to butterfly pea being used as a cover crop but it’s something “you definitely notice.” for coconut and cocoa plantations. However, P.T. Wood of Wood’s High Mountain it found its way into gin not through agriculDistillery was inspired when he first entural utility, but through traditional medicine. countered a Spanish color-changing gin. “It An Ayurvedic remedy for snake bites could really intrigued me, so I just wanted to try it.” be created from a decoction of flowers, roots, In 2017, they began product development. and stems.8 A brightly hued tea made from the “We started with our Treeline Gin, which is flower is drunk for a host of purported health our baseline, and then we just macerated the benefits, such as weight loss, treating anxiety or flower into that.” However, the flavor of the improving brain function. Some research supflowers was key to Wood and the team. “We ports the existence of some cognitive benefits. really, really liked the kind of earthy, floral The mechanism and compounds responsible quality.” for those results is not clear.9 Before gin, tea was Stability is the greatest challenge a distiller many people’s first exposure to butterfly pea. will experience when working with butterfly

The colors of the flowers themselves are the pea flowers and their extracts. “We put it in result of a class of compounds called anthocythe window, out in the front of the distillanins. Broadly, depending on their chemical ery and let it bake in the sunshine,” P.T. said, structure and the pH of the solution they are in, describing how they tested their macerated they can span a wide range of colors from red to butterfly pea flower prototype. “It was color deep almost blackish blues.10 Anthocyanins are stable for a month or so and then it turned found in a wide variety of foods: Cabbage, berthis kind of funky brown color.” Compass ries, corn, and grapes to name a few. Distillers’ first batches lost their color entire-

While beautiful and vibrant, the greatest ly after a few months. challenge with colorings based on anthocyaThough butterfly pea flower is more stable nins is stability. However, that’s where butterthan other anthocyanin-based colorings,13 it fly pea differentiates itself. The flowers include is still prone to degradation and is especially a subclass of anthocyanins that have a “much temperature sensitive.14 Held at room temhigher color stability.”11 perature, there was no perceptible change over a two week observation period.15 At 80 degrees F the anthocyanin content degraded 8 Mukherjee 2008. 9 Jaine 2003. 13 Jiang 2019. 10 Marapaung and Pramesthi 2020. 14 Marapaung, Lee and Kartawiria 2020. 11 Marapaung and Pramesthi 2020. 15 Chu 2016.

by 50 percent over four weeks;16 at even higher temperatures the degradation in color is more pronounced.17 The effect of UV light is much the same as heat.18 Some colored gins, like New Zealand’s Scapegrace, are bottled in colored glass to reduce the color degradation effects of light. Wood described looking at shaded glass as “kind of a bummer … but not having brown gin on the shelf ultimately was more important.”

However, studies of stability have shown that the presence of sugar can prolong color stability, provided pH remains constant.19 In other words, the color changing effect is preserved while increasing the resistance to heat induced color change. The type of sweetening agent didn’t matter either. Sucrose (table sugar), glucose (honey) and maltose (malt sugar) all improved the stability of butterfly pea flower colorings.20

Compass Distillers’ Gin Royal adds both honey and royal jelly (about 10 percent sugar by volume) after distillation. Though their inclusion has a positive impact on color stability, they were included to help add “balance” when mixing with tonic water.

Finally, the presence of headspace — that is the amount of gas between the top of the liquid and the seal — can accelerate thermal degradation, especially at warmer temperatures (greater than 86 degrees F). At ambient room temperature in the dark, headspace did not matter.21 In other words, if your drink with butterfly pea flower is protected from heat and UV light, a half full bottle will retain color as well as a full bottle. The issue of headspace is less a challenge at the distillery, but more of a problem in the market. Behind the bar, it may lose color if it doesn’t move at a certain pace. In the home, it may lose color if owned by an occasional drinker or as part of a gin collection.

16 Marapaung, Lee and Kartawiria 2020. 17 Chu 2016.

18 Tantituvanont 2008.

19 Chu 2016.

20 Marapaung and Pramesthi 2020. 21 Marpaung 2017.

the PATH FORWARD for AMERICAN DISTILLERS

Despite the approval of butterfly pea flower as a coloring agent, it’s important to note that what has been approved by the FDA is the extract, not the flowers. American distillers looking to produce a color-changing gin, at least for now, will be limited.

Wood has looked into using Sensient’s butterfly pea flower extract, and a few challenges present themselves. Firstly, the extract must be refrigerated. He joked that when he was looking into it, the minimum order size was enough to make “twenty thousand bottles or something crazy.”

Furthermore, if you were hoping to add the taste of the flowers, the extract is not going to cut it. It is just the coloring. “We're trying to kind of reformulate our [gin’s] botanical list to re-mimic that original flavor that we really liked, but,” he continued, “I think from an industrial standpoint, the extract makes a lot more sense. It's got a lot more color stability to it.”

It remains possible that the ingredient itself will one day be formally approved, though P.T. isn’t so confident that it will be driven by a small distiller. He and his business partner explored the process required by the FDA, but the amount of lab work, time, and money to gain that approval was too onerous for them to take on. Further, whoever does that work will have to be motivated by the particular and subtle flavor of the ingredient as opposed to the color changing aspect.

While much of the color-changing spirits phenomenon has come from the world of gin thus far, gin isn’t the only spirit where the extract can be applied. Rick Hewitt founded Unicorn Vodka, a vodka infused with the extract. Bartenders around the world have been infusing other spirits with butterfly pea flower, especially tequila and rum, for their in-house cocktail programs. It seems likely that we’ll see some attempts in coming years to bring the color-changing craze to new categories.

(a) Identity. (1) The color additive butterfly pea flower extract is a dark blue liquid prepared by the aqueous extraction of dried butterfly pea flowers from Clitoria ternatea. The extract is further processed by ultrafiltration to remove residues of plant products, followed by concentration and pasteurization. Citric acid may be used to control the pH. The color additive contains anthocyanins as the principal coloring component. (2) Color additive mixtures for food use made with butterfly pea flower extract may contain only those diluents that are suitable and are listed in this subpart as safe for use in color additive mixtures for coloring foods. (b) Specifications. Butterfly pea flower extract must conform to the following specifications and must be free from impurities, other than those named, to the extent that such other impurities may be avoided by good manufacturing practice: (1) pH, not less than 3.0 and not more than 4.5 at 25 °C. (2) Lead, not more than 1 milligram per kilogram (mg/kg) (1 part per million (ppm)). (3) Arsenic, not more than 1 mg/kg (1 ppm). (4) Mercury, not more than 1 mg/kg (1 ppm). (5) Cadmium, not more than 1 mg/kg (1 ppm). (c) Uses and restrictions. Butterfly pea flower extract may be safely used for coloring alcoholic beverages, sport and energy drinks, flavored or carbonated water, fruit drinks (including smoothies and grain drinks), carbonated soft drinks (fruit-flavored or juice, ginger ale, and root beer), fruit and vegetable juice, nutritional beverages, chewing gum, teas, coated nuts, liquid coffee creamers (dairy and non-dairy), ice cream and frozen dairy desserts, hard candy, dairy and non-dairy drinks, fruit preparations in yogurts, and soft candy in amounts consistent with good manufacturing practice, except that it may not be used for coloring foods for which standards of identity have been issued under section 401 of the Federal Food, Drug, and Cosmetic Act, unless the use of added color is authorized by such standards. (d) Labeling requirements. The label of the color additive and any mixtures prepared therefrom intended solely or in part for coloring purposes must conform to the requirements of § 70.25 of this chapter. (e) Exemption from certification. Certification of this color additive is not necessary for the protection of the public health and therefore batches are exempt from the certification requirements of section 721(c) of the Federal Food, Drug, and Cosmetic Act.

SOURCE: www.ecfr.gov/current/title-21/ chapter-I/subchapter-A/part-73/ subpart-A/section-73.69

While slightly more restricted than distillers in other countries, American distillers no longer need to sing the blues and sit out this moment in the gin zeitgeist. Despite being initially labeled a fad, these spirits have remained surprisingly strong sellers, and continue to inspire and intrigue with a simple chemistry trick in tasting rooms and bars around the world.

Aaron Knoll is a noted gin historian, critic, and consultant. He authored 2015's “Gin: The Art and Craft of the Artisan Revival,” which has since been translated into three languages, and additionally co-authored 2013's “The Craft of Gin.” He also founded leading gin website TheGinisIn.com in 2009.

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