Growing winemaker Gusbourne Estate planted another 50 acres of vineyards in Kent as the company made pre-tax losses of £516,000 in the first half of the year.

The expansion in May means 155 acres are under vine near its Appledore base, on the edge of Romney Marsh, following a larger than expected harvest last year, which has boosted stock levels.

It sold £194,000 of wine in the first six months of the year, which is thought to be 143% higher than the same period the year before under its previous ownership, although this figure is unaudited.

Bosses played down the company’s net loss of £501,000, up from £202,000 in the first six months of 2013, saying it reflects the sparkling wine producer’s “ongoing investment”.

The losses are down to the costs of planting its new vineyards and the ongoing costs with its vineyards established in West Sussex in May last year, plus the purchase of more equipment.

The company expects another strong harvest this year. Fellow Kentish producer Chapel Down, based in Tenterden and Blue Bell Hill, has predicted its harvest will grow by 10% this year.

Chairman Andrew Weeber said: “I am pleased to report further steady progress towards the achievement of our long term goals.

“A larger than expected harvest last year has added significantly to our stock levels for sale in future years and there are good prospects for a similar excellent harvest this year.

“The production of premium quality wine from new vineyards is, by its very nature, a long term, and generational business.

“It takes four years to bring a vineyard into full production and a further four years to transform these grapes into an exquisite sparkling wine.

“Our long term plan includes additional investment in new vineyards, increased winemaking capacity, wine stocks and most importantly, brand development.

“We appreciate the support our shareholders provide to us and we are proud to be the only English vineyard to be quoted on AIM.”

Gusbourne listed on the AIM market of the London Stock Exchange last year and is majority owned by Conservative peer Lord Ashcroft.

It won an International Wine Challenge gold medal for Gusbourne Brut Reserve 2009 in May 2014 and was a finalist in the Best Drinks Producer category of the 2014 BBC Food and Farming awards.