Waitrose Cecil Crowned Champion in Supermarket Caterpillar Cake Showdown
In a stunning reversal of fortunes, the long-standing rivalry between M&S and Aldi over chocolate caterpillar cakes has been upended by a new winner. According to a comprehensive blind taste test conducted by consumer advocacy group Which?, Waitrose's Cecil Chocolate Sponge Cake has emerged as the undisputed champion, leaving M&S's iconic Colin the Caterpillar in last place.
The Taste Test Results: A Shocking Upset
A panel of 75 UK shoppers participated in the blind taste test in March 2026, evaluating nine different supermarket caterpillar cakes based on flavor, texture, aroma, and appearance. The results delivered a dramatic conclusion that has sent shockwaves through the grocery industry.
Waitrose's Cecil Chocolate Sponge Cake, priced at £9.50, achieved an impressive overall score of 78%, earning a best buy rating from Which?. Despite being one of the more expensive options, its 744g size made it the largest cake in the test, rendering it more cost-effective than many budget alternatives. Testers praised Cecil for its "flavoursome thick chocolate shell" and "perfect" sponge-to-buttercream ratio, with 69% of participants particularly noting its "remarkably moist" texture.
The Runners-Up and Middle Ground
Securing joint-second place with scores of 73% were Co-op's Party Time Charlie Chocolate Cake (£9.85) and Sainsbury's Birthday & Celebration Wiggles the Caterpillar Cake (£8.50). Charlie, though the priciest entry, impressed with its "spot on" chocolate flavor and "rich" buttercream, which balanced a slightly dry sponge. Wiggles was celebrated as the ultimate Colin "lookalike" but at a more affordable price, though its sponge lacked the moistness of the Waitrose winner.
In third place, both Aldi's Cuthbert the Caterpillar Cake (£6.99) and Morrisons' Morris the Caterpillar Celebration Cake (£9) scored a respectable 72%. Cuthbert demonstrated its merit beyond marketing with a "creamy" texture, though its sponge fell short of higher-ranked cakes. Morris boasted the lowest sugar content and the best-rated buttercream texture among all contenders.
The Bottom of the Rankings
Asda's Letty the Caterpillar Cake (£9) followed with 68%, while Lewis & Green's Caterpillar Celebration Cake (£4.50 at Iceland) scored 67%. Near the bottom, Tesco's Slinky Caterpillar Cake (£9) managed only 66%.
Most shockingly, M&S's Colin the Caterpillar Cake (£9.50) finished last with a mere 64% score. Approximately half of testers found it "too dry," while two in five criticized its chocolate flavor as "too weak." Further compounding the disappointment, Colin was identified as the least healthy option, containing the highest levels of sugar (46.3g) and fat (21.3g) per 100g.
M&S Responds to the Criticism
M&S has defended its flagship product, highlighting that Colin was named the nation's best caterpillar cake in an independent YouGov poll from March 2026. The retailer also emphasized that Colin boasts the highest chocolate content on the market at 39.5%, made from 31% cocoa solids and 100% Fairtrade cocoa.
An M&S spokesperson stated: "Colin the Caterpillar is the UK's number 1 caterpillar cake – over a million are sold every year. Made and finished by hand in the UK for over 35 years, it leads the market on quality and taste. At M&S, blind taste testers regularly taste our products against the market to ensure we remain number one for taste and quality – this includes our Colin cakes, which consistently come first in taste tests."
Testing Methodology and Expert Insight
The blind taste test was conducted in private booths to prevent discussion or influence among participants. Scores were weighted with 50% for flavor, 30% for appearance, 10% for aroma, and 10% for texture. Testers evaluated visual appeal separately before sampling slices.
Natalie Hitchins, head of home products and services at Which?, commented: "For many of us, a caterpillar cake is the ultimate nostalgia trip, but our test shows that you shouldn't let brand fame dictate your birthday budget. While M&S created the category, rivals like Waitrose and even budget-friendly Iceland are now delivering a better slice of the action. Whether you're looking for the best taste or the best price, there are better options out there than the original Colin."
Final Rankings Summary
- Waitrose Cecil Chocolate Sponge Cake: 78%
- Co-op Party Time Charlie Chocolate Cake and Sainsbury's Wiggles the Caterpillar Cake: 73%
- Aldi Cuthbert Caterpillar Cake and Morrisons Morris the Caterpillar Celebration Cake: 72%
- Asda Letty the Caterpillar Cake: 68%
- Lewis & Green Caterpillar Cake: 67%
- Tesco Slinky Caterpillar Cake: 66%
- M&S Colin the Caterpillar Cake: 64%
This taste test revelation marks a significant shift in the supermarket cake landscape, challenging long-held perceptions and offering consumers new guidance for their celebration purchases.
