For a small can of mostly sugar and caffeine, there may be a lot riding on Exit. Marketed as the world’s first kosher energy drink for ultra-Orthodox Jews, its makers boast that it will help fuel the religious students whose labours are believed to safeguard the spirit of Israel.

Exit, an orange liquid modelled on Red Bull and a slew of other energy drinks, is already selling well in Jerusalem’s ultra-Orthodox community, guzzled down by religious students cramming in 14 hours of scripture every day.

“It’s a drink the ultra-Orthodox lack,” said Kfir Cohen, the Israeli businessman behind the brew, which consists of 58 different extracts and was developed over 18 months at a cost of $500,000 (£250,000).

“There are three things going on here. They make a lot of babies, they study the Torah and they dance. They need a lot of energy, and something to strengthen them.”

Israel’s burgeoning ultra-Orthodox community, distinctive in their conservative black suits, black hats and curly sidelocks, now constitute 11 per cent of the population, up from five per cent a decade ago. Most live on government subsidies and refuse to serve in the armed forces, preferring instead to dedicate their time to studying the Torah, Talmud and other Jewish scripture, which they say protects the country from its foes.

While mostly poor, they are a growing sector of the market in Israel and abroad. As well as targeting the young boys who spend their days studying scripture at the religious schools known as yeshivas, Mr Cohen hopes to plug into a market that celebrates 6,000 weddings and 36,000 circumcisions a year. Traditionally ultra-Orthodox Jews dance wildly at such celebrations, needing – Mr Cohen hopes – regular boosts of energy.

His company went to great lengths to obtain the highest certificate of kosher purity, which involved allowing rabbinical experts to examine each stage of production and every ingredient of the drink, something other soft drink manufacturers, protective of their secret recipes, may be wary of. But the efforts appear to have paid off.

“It’s selling very well, especially if there’s a wedding on” said Shaul Saydan, who runs a grocery shop in one of Jerusalem’s ultra-Orthodox communities. “It’ll definitely take over the energy drink market here, and there’s a big market in Jerusalem.”

David, an 11-year-old yeshiva student, said that his religious school had forbidden the drink on its premises – the label recommends children under the age of 12 do not consume it – but that he and his friends drank at least a can a day each to help them concentrate on memorising the sacred texts. “It tastes pure and clean because we know the ingredients are pure,” he said. “All my friends drink it; we study 14 hours a day.”

David Zilbershlag, publisher of an ultra-Orthodox newspaper and a respected community leader, also welcomed the drink, which he said could help yeshiva boys to stay sharp. “It’s a very good idea, especially on the Thursday night vigils” – when yeshiva students stay up all night poring over the scrolls – he said. “This can be a good substitute for the coffee and cigarettes they use to stay awake.” It could also replace alcohol at weddings and other celebrations, he added, recalling that the Torah – a key Jewish text – explicitly commands Jews to “be joyful” at such events.

More significantly, an energy drink that keeps Jewish students alert in their studies helps safeguard the state of Israel, some believe. “It is written that studying the Torah protects the land,” Mr Zilbershlag said, citing an argument the ultra-Orthodox have long used to avoid military service.

Mr Cohen has successfully tapped into that belief, promoting his drink with the logo “Exit is a joy for your soul.” But the market is larger than Jerusalem or even Israel and Exit will soon be on sale in the Britain and America. And Mr Cohen said that since the Muslim standards for food purity are similar to Judaism’s, his drink may be able to tap into the $40 billion global kosher and halal markets.

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