Supermarket basics soared in price by up to 30% on a yearly basis last month - as worrying research shows how shoppers are feeling the squeeze in stores.
The huge increase was highlighted in the Which? inflation tracker, which reveals how prices have changed at Aldi, Asda, Lidl, Morrisons, Ocado, Sainsbury’s, Tesco and Waitrose.
Across the eight retailers, butters and spreads went up an eye-watering 29.4%. Milk prices rose by 26.3% and cheese was up 22.3% during the same period.
The tracker - which looked at tens of thousands of food and drink products across three months - shows overall food and drink inflation in December was at 15%.
It comes as overall Consumer Prices Index (CPI) inflation was this morning confirmed to have dipped slightly from 10.7% to 10.5% in the 12 months to December.
The worst individual price hike noted by the Which? track was Quaker Oat So Simple Simply Apple (8x33g) at Asda which shot up a staggering 188% from £1 in December 2021 to £2.88 in December 2022.
Utterly Butterly (500g) rose 95% from £1 to £1.95 at Waitrose, while one pint of Waitrose Duchy Organic Homogenised Semi-Skimmed Milk (568ml) increased 87.1% from 65p to £1.22.
Tesco Creamfields French Brie 200G went up in price by 81.59% from 79p to £1.43.
Budget and own-brand items again went up at a faster rate - 20.3% and 18.5% respectively - compared to premium and branded counterparts - up 12.6% and 12.5%.
Lidl prices went up the most at 21.1% in December, followed closely by Aldi at 20.8% - although Which? says both supermarkets are still cheaper overall compared to other stores.
Asda had the third highest inflation where prices rose 15.4%.
Inflation rose slightly less at Waitrose at 14.5%, followed by Sainsbury’s on 13.7%, Tesco at 13.1%, Morrisons on 12.9% and Ocado with 10.5%.
Supermarket shoppers have told Which? of their dismay over how fast prices are rising.
One participant, a man in his late 30s from the South East, told Which?: “The cost of food from supermarkets is close to unmanageable for many people, including myself.
“Given that large supermarkets make huge profits, I feel they could keep their prices down while we struggle with the cost of living.”
A 43-year-old woman from Yorkshire and Humberside said supermarkets “don’t care about the consumer and charge whatever they can to make as much profit as possible.”
Sue Davies, Which? Head of Food Policy, said: “We know food prices have risen exponentially in the last year and our inflation tracker shows the dramatic impact this is having on everyday products at the supermarket.
“Some households are already skipping meals to make ends meet and our findings show trust in supermarkets taking a hit as many people worry they are putting profits before the people suffering during this cost of living crisis.
“Supermarkets must do more, Which? is calling for them to ensure everyone has easy access to basic, affordable food ranges at a store near them, particularly in areas where people are most in need.“
A spokesperson for Asda said: "We have a long-standing reputation for providing customers with outstanding value and it’s more important than ever that we deliver on this for them.
"We’re focused on keeping prices on branded and own-label products in check to ensure that Asda remains the lowest-priced traditional supermarket as shown by independent research carried out by Which? Magazine.”
A Waitrose spokesperson said: "With the increase in production costs for primary products and the war in Ukraine, no retailer is immune to inflation, however our overall price inflation is much lower than the examples selected, which have been impacted disproportionately.
"We’re working very hard with our suppliers to ensure we offer great value, while continuing to deliver industry-leading animal welfare standards, fresh produce grown with care and fair deals for farmers."
A spokesperson for Morrisons said: "We are working hard to keep prices down and competitive for our customers while maintaining high standards and availability in all our stores.
"Since December we have invested over £16 million to cut the prices on over 50% of our entry level products to help customers' money go further."
An Aldi spokesperson said: "We are the lowest-priced supermarket in Britain. Our customers will always pay less for their shop with Aldi and that is why Which? has named us as the cheapest supermarket in 2022.
"Value is the number one consideration for most households and our promise to our customers is that we will always provide the lowest grocery prices in Britain."
