Good wine is usually considered the result of fermentation techniques or terroirs. Biblical law rarely comes into it.

But in Israeli wine contests, a new generation of ultra-ideological religious-Zionist winemakers is enjoying considerable success - which they are crediting to their observance of Shmittah, the agricultural sabbatical year, when they leave vineyards untended.

The Shmittah-observant winemakers, typically in their thirties, run boutique wineries deep inside the West Bank. Last month, following a blind tasting by experts at Eshkol Hazahav, one of Israel's most prestigious wine awards, seven of the 50 accolades went to West Bank wineries.

Shivi Drori, winemaker at the Gvaot winery in the tiny settlement of Givat Harel, won a bronze. Ahead of the awards, he had thought about the religious tradition that Shmittah observers would be successful agriculturally in the years before Shmittah.

"Two of us were sitting next to each other at the award and laughing - it was happening," he said.

Winemakers credit their success to their observance of shmittah

The most successful West Bank winery at the awards was the organic Hararei Kedem, from Yitzhar. The 130-family settlement is widely considered to be a stronghold of extremists and recently, a clash between security forces and a group of residents left at least two soldiers wounded by stones.

The winery's employment policy reflects the local hard-line ideology. While many settler businesses employ Arab labourers, there only Jews are considered for jobs.

"We don't give parnasah [livelihood] to our enemies and we do give parnasah to our brothers, Jews," said winemaker Ariel Ben-Sheetrit.

Mr Ben-Sheetrit, who was just 20 when he planted his vineyard 12 years ago, won two gold medals and one silver. He told judges that his success should be viewed "as truly a fulfillment of the words of the Torah."

He claims that supernatural forces helped the quantity and quality of his grapes. According to his records, the harvest in a normal year is 4.5 tonnes, while in the year preceding Shmittah it was 14.5 tonnes.

For most of the 12 boutique wineries in the West Bank, the Shmittah year of 2008 was their first. In was only in 1998 that the World Zionist Organisation began encouraging settlers to grow grapes, a low-water crop, because of the acute water shortage in the region. Their pre-Shmittah vintages are just now coming up at awards tastings.

But there are more biblical connections to the West Bank wineries. Vineyards are concentrated in the Samaria region, and winemakers constantly cite the verse from Jeremiah: "Again you will plant vineyards on the hills of Samaria."

"We try to see ourselves as the people who resume what was stopped 2,000 years ago - we are just putting this back in place," said Mr Drori.