Britons may want to start spending more time in their kitchen after a new survey shows that money saved on utility bills is being washed down the kitchen sink.National Savings and Investments (NSI) reported that many households think they save around 75 a month by spending less on groceries and utilities over the summer months.Rather than stash this cash away for a more rainy day, holidays, socialising and attending parties push up the monthly average spent on such activities by more than 100.But there could be some financial benefits to the summer, with 34 per cent claiming they save cash on food by giving their home-grown produce a wash in the kitchen sink to be used for meals.Dax Harkins, NSIs savings strategist, advises Britons to plan cost-effective ways to have fun and to check what free activities are on in your local area or perhaps consider packing up a picnic for an outdoor lunch rather than going to a restaurant.People may also want to make the most of their kitchens for entertainment this summer by inviting friends round for a cheap home-cooked meal.Author Marian Salzman told the Financial Times that the kitchen will become an important social hub across the UK as the credit crunch changes the values of households.