Colin the Caterpillar put to test against supermarket competitors in blind tasting

Consumer champion group Which? enlisted a 75-strong panel to sample nine caterpillar cakes in a blind test that assessed flavour, texture, appearance and aroma.

The purpose was to find out which brand proved most popular according to taste and enjoyment.

Although the overall design varies, all the cakes typically comprise a rolled chocolate sponge filled with chocolate-flavoured buttercream, and covered in a solid chocolate shell.

While Colin and Cuthbert are perhaps the best known (edible) caterpillars around, neither one took home the top spot in the blind test.

Instead, despite its high price tag, it was Waitrose’s Cecil that was named ‘best’ caterpillar cake.

At 744g, Cecil is the biggest caterpillar cake Which? tested, so although it’s more expensive than most overall at £9.50 (serves 12), it’s one of the cheaper cakes by weight.

Which? reports that Cecil won hearts for the strength of its chocolate flavour, sweetness and thickness of its shell, with a score of 78%.

The panel described the sponge’s texture as spot on and almost 70% said the sponge-to-buttercream ratio was perfect.

In joint second place was Co-op’s Charlie and Sainsbury’s Wiggles – each with a score of 73%.

Co-op’s Charlie is the most expensive on the list at £9.85 (serves 12) but it’s also a sizeable cake at 702g.

Sainsbury’s version holds the closest resemblance to Colin but is also the smallest cake in the group, weighing 613g. It serves up to 14 people and is priced at £8.50.

Both cakes were ranked lower due to tasters finding the sponges ‘a touch too dry’.

Third place also saw a joint win, with Aldi’s Cuthbert and Morrisons’ Morris, both claiming a score of 72%.

Cuthbert weighs 624g and is priced at £6.99, while Morris The Caterpillar Celebration Cake weighs 38.4g and is £9. Both cakes serve 12 people.

Perhaps surprisingly, M&S received a score of 64%, below that of Asda’s Letty, Iceland’s Lewis and Green, and Tesco’s Slinky Caterpillar Cake.

Commenting on the results, M&S told Which?: “Colin the Caterpillar is the UK’s number 1 caterpillar cake – over a million are sold every year. He has been named the nation’s best caterpillar cake in an independent YouGov poll.”

The YouGov data that ranked Colin first was from a total sample size of 2,122 adults. Fieldwork was undertaken between 27 and 30 March 2026. The survey was carried out online. The figures were weighted and are representative of all UK adults.

For Which?, 44% of its taste testers found Colin’s sponge too dry and 40% said the chocolate flavour was too weak.

The panel did enjoy the thickness of the chocolate shell and the texture of the buttercream, however.

Colin weighs 625g and is priced at £9.50, serving 12. The M&S cake also had the highest sugar and fat content of the cakes tested (46.3g of sugar and 21.3g of fat per 100g).

Manufacturer Finsbury Food Group is behind the majority of those ranked in the top tier and has welcomed the results.

Adam Arnott, group grocery sales director at Finsbury Food Group, said: “Caterpillar cakes hold a special place in British celebrations, so we know how important it is to get every detail just right. From the depth of the chocolate flavour to the balance of sponge and buttercream, our teams spend countless hours refining recipes, testing textures and perfecting finishes.”

“What’s particularly exciting about this result is that it was a blind taste test. It shows that when branding is stripped away, what truly stands out is quality and flavour, and that’s exactly what we strive to deliver for our retail partners and their customers every day.”