The groceries you should never pay full price for

The price of groceries has rarely left the headlines over the past few years – and now another wave of food inflation looks set to hit shoppers. 

The conflict in the Middle East has made the cost of fuel and fertiliser soar, sending shockwaves through global food and drink supply chains. 

Our supermarket food inflation tracker shows that the price of supermarket food and drink was up 2.4% in May compared to the same period the year before. But experts warn it could hit double figures by the end of the year. 

All this means getting the best deal on your weekly shop is more important than ever. But are grocery prices really what they seem? 

Our investigation analysed the pricing of thousands of popular branded groceries over a year to uncover the truth about grocery promotions. Here we reveal the tricks of the trade and teach you how to see through the smoke and mirrors of grocery pricing. 

The groceries always on offer

More shoppers are looking for deals due to concerns about rising prices: spending on grocery promotions rose nearly 8% year-on-year, according to analysts Worldpanel by Numerator. Indeed, about a third of what we spend on groceries is on so-called ‘deals’. 

But the truth about grocery pricing is more complex than it first appears. 

We’ve found that deals on some branded groceries are so common that you never need to buy them at full price at all. These include Fox’s Chocolatey Milk Chocolate Rounds, Jammie Dodgers raspberry biscuits, Penguin bars, Special K cereal, Mini Cheddars, Twiglets, Kettle Chips, Tropicana orange juice and Onken yoghurt – all of which had products on a deal at one major supermarket or another every single day of the year. 

Wine lovers beware, too: several popular bottles were also always on promotion somewhere. These included Yellow Tail merlot and Taittinger champagne.

• Find out more: Which is the cheapest supermarket?

What to pay for Special K 

Take popular breakfast cereal Kellogg’s Special K Original Cereal (440g). 

This had a full price of between £3.30 and £3.50 at the major supermarkets throughout the year. 

But if you shopped around, you would always have been able to buy it somewhere for £2.85 or less.

In reality, it’s unlikely you would shop around just for a deal on one  box of cereal, but it illustrates a  wider point: you should take some full prices with a pinch of salt.

Grocery deals can also last a long time, so you don’t need to rush. 

That same box of Special K was  on promotion at Ocado 51% of the year, at Tesco 50%, Waitrose 48%, Sainsbury’s 45%, Asda 29% and Morrisons 29%, with its discounted price as low as £2.63.

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Dizzying price fluctuations

Grocery promotions tend to follow a pattern of three or four weeks at a lower price, followed by slightly longer at a higher price, repeating almost indefinitely.

These cycles led to some crazy prices. One of the most striking was Light & Free Peach Passion Fruit Greek Style Yoghurt (4 x 115g): £1 at Ocado at its lowest and £2.90 at its highest at Waitrose – a difference of 190%.

But you don’t always need to shop around to bag low prices. Even at the same supermarket, we found price fluctuations of up to 213% – at Asda, Amaara Plain Poppadoms (200g), were 48p at their cheapest and £1.50 at their most expensive. So don’t assume the full price of branded groceries is what you should pay. It’s usually way over what you could be paying elsewhere or at another time. 

If you’re able to stock up on non-perishable, freezable or frozen groceries when they’re discounted, you should. 

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

How do promotions work?

Supermarkets set prices, but these are influenced by the manufacturer and other supply chain costs. Manufacturers work with supermarkets to plan when deals will happen and what type of promotions to use. Each manufacturer will allocate a budget to fund promotions, and these will be scheduled in advance at different supermarkets.

Manufacturers also frequently look at whether they are offering the right types of pack sizes or formulations. Brands commonly tweak products for discount supermarkets such as Aldi and Lidl, for example.

Retail analyst Bryan Roberts, from the Institute of Grocery Distribution, suggests shoppers should cherry-pick products based on promotions. He said: ‘A little bit of legwork really can pay dividends.’

But there can be tension between brands and supermarkets. Filippo Berio boss Walter Zanre recently accused supermarkets of ‘taking the mickey’ out of shoppers for not reducing prices in line with the falling costs of olive oil. 

The cheapest supermarket for branded groceries

Generally, own-label products are cheaper than bigger-name brands and can taste just as good.

However, if you do prefer buying branded groceries, you’ll find our newly launched monthly branded grocery price tracker useful. It reveals just how stark the price differences are between supermarkets on branded groceries such as Heinz beans, Nescafé coffee and Mr Kipling cakes.

So far, Asda has been the cheapest for branded groceries, with Tesco and Sainsbury’s most expensive for those without a loyalty card– pricier, even, than Waitrose or Ocado. It shows that switching offers big savings.

6 savvy tips to save on groceries

Looking closely at labels and searching for things in different places can really pay off - here are some of our best expert tips:

1. Check secret codes

You don’t have to rush to grab a bargain if you know when a deal ends. Supermarkets have secret codes on their shelf labels. Tesco reverses the end date, Sainsbury’s shows the start date (deals usually last about a fortnight) and Waitrose uses a four-digit month-and-year code.

2. Try different aisles

Some groceries, including rice, sauces and baking ingredients, can be found in multiple aisles at different prices. Check out the world food aisle for cheaper rice or spices, and look for sultanas, cashew nuts or dried fruit in the baking aisle – packs tend to be bigger but can work out cheaper per 100g.

3. Join loyalty schemes

Our research has found loyalty prices can save you up to 7% on a large shop. So sign up if you can – as long as you don’t mind handing over your data. But don’t switch supermarkets purely because of loyalty prices; regular discounts elsewhere are often as good.

4. Compare unit pricing

Always check out the unit price – that’s the price per 100g or 100ml – which helps you compare different products and sizes at a glance. We’ve repeatedly found unit pricing to be inconsistent, but the government has just bought in new regulations that should make it better for shoppers. 

5. Avoid convenience stores

Shopping in supermarket convenience stores costs more than going to their larger shops – up to 21% more at Morrisons Daily, 14% more at Sainsbury’s Local and 11% more at Tesco Express, according to our 2024 cost of convenience research. The cheapest items also aren’t always widely available at smaller stores.

6. Try own-brand groceries

Sarah Joan Ross, Which? food editor, says: 'We’ve all been seduced by big-brand labels on the weekly shop. But supermarket own brands frequently top our taste tests. These supermarket products can be under half the price of big brands, yet they don’t seem to sacrifice taste or quality. 

'Aldi and Lidl often do well in these tests, punching well above their price point. Both of these supermarkets scored highly this year for luxury pork sausages, beer and baked beans. Aldi also came out on top for smoked salmon, Yorkshire puddings and instant coffee, too.' 

• Find out more: Best supermarket food and drink