* 3 measures of Gordon's gin
* 1 measure of vodka
* ½ a measure of Kina Lillet

The ingredients should be shaken until ice cold and serve in a deep champagne goblet - or in a martini glass in the movie - with a large thin slice of lemon peel.

While Gordon's gin and vodka are easy to find, many Bond fans had never come across Kina Lillet. And to make matters worse, the name of the product was changed decades ago and the product formula changed to remove the bitter aftertaste mentioned in the film.

So what is - or what was Kina Lillet?

Kina Lillet was introduced in the late 19th century, when it was fashionable to drink wine based tonics that included a variety of flavourings, including quinine, as well as fruit liqueurs. While the original product was known as "Kina Lillet" - kina signifying that it contained kina-kina, or quinine - contemporary ads show that "Kina" was gradually reduced in prominence and by the 1930s it seems that the product became known simply as "Lillet". When Ian Fleming wrote Casino Royale in 1952 it coincided with a cocktail renaissance and Lillet became popular in both England and the United States.

Kingsley Amis questioned Fleming's choice of Kina Lillet in what was later dubbed the Vesper, saying that its bitterness would have made the cocktail undrinkable and that Fleming had meant "Lillet vermouth" - probably a product known as Lillet Dry, formulated for the English market.

However, it is impossible to test Amis' assertation because the company that produces Lillet was taken over in the 1980s and modernised. Part of this included updating manufacturing techniques to modern standards, but it also included changing the recipe for Lillet to make it more appealing for the modern palate, and that included reducing the amount of quinine and therefore the distinctive bitterness from the drink.

Today you can find two varieties of Lillet; Lillet Blanc and Lillet Rouge, which was introduced in the 1960s. It is the former that you should acquire if you want to mix Vespers at home.

While the bitterness has been much reduced, it has been proposed that to achieve the original flavour of James Bond's cocktail, one should add quinine powder to the cocktail mix. Another alternative is to add a dash of bitters to give that distinctive flavour.

Today Lillet is still manufactured in Podensac, in the Bordeaux region of France. The company changed hands from private ownership in early 2008, when it was taken over by Pernod Ricard. While the increased interest in Kina Lillet seems to have taken the company by surprise and they have failed to capitalise on the free publicity provided by James Bond, it remains to be seen whether the new owners will do more to boost its popularity once again.