The price of some branded items such as cakes, yoghurt and cheese has more than doubled in the last 12 months, according to data from Which?.

It found a packet of six Mr Kipling chocolate slices in Tesco, for example, went from £1.16 on average in 2022 to £2.66 in July 2023, a rise of 129%. In Sainsbury’s a six-pack of Mr Kipling bakewell cake slices rose in price to £2.75, up from £1.37, an increase of 99%.

The research from Which? scanned prices of almost 26,000 food and drink items across eight major UK supermarkets – Aldi, Asda, Lidl, Morrisons, Ocado, Sainsbury’s, Tesco and Waitrose.

Yoghurts, cheese and porridge

Which? said branded products have a lower annual inflation rate (12.2%) than supermarket own brand ranges (14.6%) and budget ranges (24.3%), but they tend to cost more overall.

Among the other significant price rises was Lancashire Farm natural yoghurt, with a pot costing £1.80, a rise of 80% from the earlier £1 price tag at Asda.

The cost of a 180g pack of Pilgrims Choice extra mature grated cheddar rose to £2.11 from £1.20 at Morrisons – a hike of 76%. The cost of a 900ml bottle of Tropicana juice also rose by 66%, from £1.84 to £3.05.

At Ocado the price of an Oat So Simple porridge pot rose to £1.60, from 92p, an increase of 73%. Meanwhile, Dale Farm skimmed milk 2ltr at Tesco was hiked from £1 to £1.75.

Food prices have rocketed in the last year as a result of the rising price of animal feed, fertiliser and fuel along with energy and labour costs. The Bank of England’s chief economist also recently said food prices may never return to those seen before the pandemic.

Convenience shops must stock budget ranges

Which? is calling on supermarkets to make sure that convenience shops stock essential budget ranges. Morrisons has already begun offering budget lines in its smaller shops and Tesco has announced it plans to do the same.

Sue Davies, Which? head of food policy, said: “The scale of price hikes to some branded products at the supermarket over the last 12 months is barely believable and highlights the huge pressure faced by shoppers, especially families and those on low incomes.

“With food prices expected to remain high for the rest of the year, Which? is calling on supermarkets to ensure expensive convenience stores are stocked with a range of budget items that support a healthy diet – and setting key tests that they can work towards to show they are willing to make a meaningful difference for their customers most in need.”

Food inflation falls

Separate research published today from Kantar showed that food price inflation eased to 12.7% in the four weeks to 6 August, a monthly drop of 2.2 percentage points. This is the second sharpest monthly fall seen since 2008.

The cost of some staple items also fell: a four-pint bottle of milk was £1.50 down from £1.69 in March, and the average cost for a litre of sunflower oil was down 22p to £2.19.

Take-home grocery sales rose 6.5% in the same period, down from 10.4% in July, largely because of the bad weather last month. Sales of ice cream, for example, were down by 30% while sales of soup rose 16%.

Sales of own-label items were up by 9.7% and branded items rose by 6.4%. The average rise to household grocery bills was £5.13, or £266.76 annually. This compares to a rise of £11.27 a week, or £586.04 a year, for households that were still buying the exact same items a year ago.

Fraser McKevitt, head of retail and consumer insight for Kantar, said: “Own-label sales continue to outpace branded, although the gap between the two is closing. Buying supermarket lines is just one of the ways people have been trying to save money at the tills and we can see the impact on how much they are spending.”

Tesco saw sales of 9.5%, boosting its market share to 27%, and sales at Sainsbury’s grew 9.3% giving it a market share of 14.8% over the 12 weeks to 6 August.

Asda’s sales were up 7.7% and at Morrisons, sales rose 8.7%. But Aldi – crowned the cheapest supermarket for 14 months in a row – was the fastest growing retailer, with sales rising by 21.2% annually. This is in contrast to a rise in sales of 19.8% at Lidl, 4.4% at Waitrose, and 3.4% at Co-op.

Related: Supermarket sweep: The grocery deals and discounts to cut your food bill