Everyday food prices soar as supermarket inflation hits 17.2%

The prices of cheddar cheese, white bread and porridge oats are up by as much as 80%, Which? research reveals. 

We analysed inflation on more than 26,000 food and drink products at eight major supermarkets – Aldi, Asda, Lidl, Morrisons, Ocado, Sainsbury’s, Tesco and Waitrose – in March to see how everyday product prices are being affected.

Which? put together a basket of staple foods including cheddar cheese, sliced white bread, pork sausages, white potatoes and porridge oats to find which of these everyday products have seen the biggest percentage price hikes and work out average prices across the eight supermarkets. 

• Find out more: what's happening to supermarket food prices?

Worst everyday foods for inflation revealed

Supermarket food and drink prices continued to rise in March, costing on average 17.2% more than in March 2022. However, some items rose far more than that.

Here's the average annual price increases on 11 popular everyday groceries across all eight supermarkets: 

These averages mask some larger increases in specific products though. 

Cheddar cheese, for example, increased by an average 28.3% across all the supermarkets in the three months to March 2023, compared to the same period the year before. But the worst example in our basket, Dragon Welsh Mature Cheddar 180g at Asda, went from £1 to £1.80 - an increase of 80% year on year.

The cost of porridge oats went up by an average of 35.5% but the worst example was at Ocado where Quaker Oat So Simple Protein Porridge Pot Original 49g went from 94p to £1.56 - an increase of 65.5%.

When we looked at large sliced white bread we found average increases of 22.8%. The Bakery at Asda Soft White Medium Sliced Bread 800g, however, went from 56p to 94p (an increase of 67%) .

For white potatoes, average inflation was around 14% across the supermarkets, but at Morrisons, a four pack of baking potatoes went from 40p to 66p - a rise of 63.5%.

Inflation on pork sausages was 26.8% on average, but Just Essentials by Asda 8 Pork Sausages 454g went from 81p to £1.40 (a 73.5% increase). Similarly, the value version at Tesco, Woodside Farms 8 Pork Sausages 454g, went from 80p to £1.39 (a 73.3% increase).

Our analysis covered the average price of the products in the three months to the end of March 2023 compared to the same time period last year.

• Find out more: which is the cheapest supermarket?

Own-label budget groceries up nearly 25%

These examples of massive price hikes on supermarket value ranges reflect the trend that it is the cheapest products at the supermarket which are being the hardest hit by inflation in percentage terms. 

Our monthly supermarket tracker shows inflation continued to rise in March to 17.2%, compared to 16.5% last month.

But the tracker shows supermarket own-label budget items, which are still the cheapest overall, were up 24.8% in March compared with the same time last year. This is more than standard supermarket own brands, which were up by 20.5%. 

Branded goods and premium own-brand ranges meanwhile were both up 13.8%.

• Find out more: how to spend less at the supermarket

How the supermarkets compare on inflation

Our tracker also looks at how inflation differs between supermarkets. 

Yet again, we found Lidl had the highest rate of inflation, followed closely by Aldi. Here's how all supermarkets compared: 

Of course, inflation is a measure of how quickly prices are rising or falling and not of absolute price. The supermarkets with the highest inflation may also be the cheapest - and in fact, according to Which?'s latest cheapest supermarket price comparison, Aldi and Lidl do have the lowest prices. 

Which?’s tracker looks at 20 popular categories of food and drink. It compares average prices across the same three-month and one-month periods year-on-year, including discounts but not multibuys or loyalty card offers. Figures are then weighted based on supermarket market share and the sales volume of each product category. 

What the supermarkets say

We put the specific products mentioned to the supermarkets for comment. 

An Asda spokesperson said: 'We’re working hard to keep prices in check for customers despite global inflationary pressures and we remain the lowest-priced major supermarket – a position recognised by Which? in their regular monthly basket comparison which has named Asda as the cheapest supermarket for a big shop every month for the last three years. We recently announced we would be freezing the prices of over 500 popular branded and own label products, more than half of which are fresh meat, dairy, fruit and vegetable products until the end of May.'

An Ocado spokesperson said: 'At Ocado, everything we do starts with our customers and we know how important value is to them right now. We continue to support our customers by investing in price across branded and own-brand products. We've also recently introduced the Ocado Price Promise so customers can be sure they’re getting great value.'

A Sainsbury's spokesperson said: 'With costs going up, we are working hard to keep prices low. In the last two years, we have invested over £550m into lowering prices as part of our goal to put food back at the heart of Sainsbury’s. We're committed to doing everything we can to support customers with the rising cost of living. Through initiatives such as our Aldi Price Match campaign, Price Lock and My Nectar Prices, customers can find low prices on the products they buy most often both in stores and online – including: butter, broccoli, cabbage, and carrots. Our focus on value means that all our customers will find great deals when they shop with us and do not need to go anywhere else to get the best prices on their weekly shop.'

A Waitrose spokesperson said: 'As Which? highlighted last month, dairy is one of the categories most impacted by inflation, and no retailer is immune to this. We’re working hard to keep our prices as low as possible, whilst paying our farmers and suppliers fairly, and maintaining high animal welfare standards.'

Aldi, Lidl, Morrisons declined to give a formal comment. Tesco did not respond. 

While some minor price variation may exist due to different prices at different stores across the country and sampling techniques, Which? is confident this is unlikely to impact overall averages and inflation figures. 

• Find out more: best and worst supermarkets 

Why supermarkets need to do more

Our findings show the dramatic impact inflation is having on everyday foods. Even 'value'-range foods are at risk of becoming too expensive for those on the tightest budgets. 

That's why our Affordable Food For All campaign calls on supermarkets to do more to ensure own-brand budget line items are widely available throughout all branches – including in convenience stores. They should also make pricing and offers more transparent. 

More than 86,000 supporters have signed our petition so far calling on the supermarkets to take action. Alongside the University of Leeds Consumer Data Research Centre, Which? has developed the Priority Places For Food Index which shows where in the UK people are the most vulnerable to food insecurity. 

Sue Davies, Which? Head of Food Policy, said: 'Our latest supermarket food and drink tracker paints a bleak picture for the millions of households already skipping meals of how inflation is impacting prices on supermarket shelves, with the poorest once again feeling the brunt of the cost of living crisis.

'While the whole food chain affects prices, supermarkets have the power to do more to support people who are struggling, including ensuring everyone has easy access to basic, affordable food ranges at a store near them, particularly in areas where people are most in need.

"Supermarkets must also provide transparent pricing so people can easily work out which products offer the best value.'

• Do you want to see your supermarket take action? Sign the petition