(TheDrinksBusinss) - A massive increase in the cost of spirit is causing problems for Port producers in the Douro, and prices are predicted to rise further. According to managing director of The Fladgate Partnership, Adrian Bridge, the spirit used to fortify grape must in Port-making (Aguardiente) has almost doubled in price from €1.60 per litre in 2011 to €3 today. He also said the price of spirit will be “higher again” next year. Bridge, who was speaking at a London tasting focused on the Fonseca Port brand, blamed the increases on a shortage of grapes for distillation following two “short harvests” in Europe, and an increasing demand for brandy.