As grocery price inflation hits another new record, consumers are turning to wonky fruit and vegetables to cut bills, figures show.

Shoppers are now paying an average of £643 more on groceries than last year after inflation hit 13.9% over September – a record high since the marketing data and analytics company Kantar began tracking prices in this way during the 2008 financial crash.

In an apparent effort to offset soaring bills, consumers sent collective sales of ranges including Tesco Perfectly Imperfect and Morrisons Naturally Wonky up 38% over the month.

Supermarket own-label lines increased by 8.1% this month, while branded items declined by 0.7%.

Marmalade sales also rose by 18% in September as the nation paid its respects to the Queen.

People also appear to be searching for cheaper ways to cook rather than using their ovens. Sales of cooking appliances including slow cookers, air fryers and sandwich makers, which generally use less energy, are up by 53%.

Meanwhile sales of duvets and electric blankets have grown by 8%, while candles increased by 9%, suggesting people may be preparing for possible winter blackouts.

Fraser McKevitt, head of retail and consumer insight at Kantar, said: “The cost-of-living crisis is still hitting people hard at the checkouts and this latest data will make tough reading for many.

“Of course, consumers are looking for ways to manage budgets and to avoid paying more for their shopping. We’re generally reluctant to change what we eat, so this is more about sticking to the food we know and love while hunting for cheaper alternatives like supermarkets’ own label goods.

“We aren’t seeing dramatic evidence of diets changing. For example, while frozen veg sales have gone up slightly, there hasn’t been a big switch away from fresh products, which are still worth 10 times more. However, one standout from the data this month was the surge in marmalade sales by 18% as the nation paid its respects to the Queen.”

The scale of price rises is trumping sustainability concerns for many people, with the proportion of British shoppers who try to buy products with more environmentally friendly packaging slipping to 59%, down from 62% last year.

Asda led the way among the biggest traditional supermarkets, attracting an additional 417,000 customers over the 12-week period.

For the fifth month in a row, Lidl was the fastest growing grocer this period, pushing up its sales by 20.9% over the 12 weeks, marginally ahead of Aldi whose sales rose by 20.7%. Lidl’s share of the market is now 7.1%, up from 6.2% last year while Aldi moved to 9.3% from 8%.