The original recipe is lost but the current one given by Raffles head barman Aaron Manzanillo is: gin (30ml), cherry brandy (15ml), Cointreau (7.5ml), DOM Benedictine (7.5ml), Angostura bitters (Dash), grenadine (10ml), pineapple juice (120ml) and lime juice (15ml). Shake well and strain into glasses filled with ice.

The key ingredient is gin.

That's where Sam Galsworthy, the co-founder of Sipsmith artisan gin, comes in.

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The Galsworthy connection

Quite by chance, Galsworthy visited the Raffles Hotel and requested a meeting with the food and beverage director the year before the drink's anniversary.

Galsworthy happens to be a descendant of Sir Stamford Raffles, the British statesman who founded Singapore and after whom the hotel was named.

"I've always felt an emotional connection with Raffles because Sir Stamford Raffles was my great, great, great, great, great grandfather," says Galsworthy, whose first name is officially Stamford.

"When I mentioned this to Nigel Moore [Raffles' F&B director], I saw his face light up as I hoped it would. But I was blissfully unaware that 2015 would be the centenary of the Singapore Sling."

The timing of Galsworthy's visit was serendipitous.

"We had started thinking about what we could do to celebrate the 100th anniversary of the Singapore Sling," explains Diana Banks, Raffles vice president of brand and luxury sales.

"It had to have elements of both the old and the new and we thought that a bespoke gin would be an excellent way to do this, but had not thought of a partner we could work with."

"I had heard about Sipsmith and their growing reputation for catalyzing the revival of gin culture in London. They share so many of the attributes that Raffles has."

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Authentic methods

When it launched in 2009, Sipsmith was the first new copper gin distillery in London to open in 200 years.

As well as producing its spirits in copper stills -- the company's three stills are nicknamed Prudence, Constance and Patience -- Sipsmith uses a "one shot" process, in which no extra alcohol is added to stretch or dilute the gin.

Originally, the Raffles team suggested creating a gin in a style similar to one available around in 1915.

But the idea was quickly overruled by Sipsmith's master distiller.

"He said 'we certainly will not'!" recalls Galsworthy.

Turns out, 1915 wasn't a great year for gin.

Spicy concoction

Instead, for its 2015 incarnation -- called Raffles 1915 -- Sipsmith incorporated spices and ingredients from Southeast Asia.

The gin is inspired by the hotel's location but is also a nod to Sir Stamford, who developed Singapore as a port for the spice trade and who had an avid interest in botany.

He even cultivated spices on Government Hill, now Fort Canning in Singapore.

Six botanicals that would have gone into an original London gin, and that go into every Sipsmith bottle, form the base of Raffles 1915: juniper, coriander, orris root, angelica, cinnamon and lemon peel.

On top of that Sipsmith has added pomelo, lemongrass, jasmine, nutmeg, mace and clove.

After some 40 variations, the Sipsmith team whittled down its recipes to two.

These were sent to Turkey, where Raffles Hotel brass were attending a conference, for the final sampling.

"It was the best part of the three days," says Simon Hirst, general manager of Raffles Singapore. "There was one clear winner that had a unique freshness and brightness."

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The 'Raffles 1915' gin

Beginning in November, Raffles 1915 is available in Raffles outlets in Singapore and Paris.

"It will be used in Singapore Slings but it's not anchored to one specific drink," says Galsworthy. "Gin is so versatile ... I love it on the rocks or in a martini."

Galsworthy also suggests a garnish of one of the Southeast Asian ingredients such as lemongrass or pomelo.

"I love crushed jasmine flowers in it," he says. "Whichever you choose will really bring that ingredient to the fore."

By the end of the year the gin will be available in Raffles hotels in Siem Reap and Phnom Penh in Cambodia, and Beijing and Hainan in China.

All remaining Raffles properties will take delivery in 2016.

"It's definitely a long haul product," says Hirst, nodding at Galsworthy. "I think we have our own copper still?"

Galsworthy who confirms that, yes, "Patience" is exclusively dedicated to crafting Raffles 1915.

"It's one of those great opportunities where everything fell into place at the right time," says Hirst.

"This is a hotel that's built on stories and this is the latest one.

"It's a match made in Singapore."