Crisps without crunch were voted the top food fail in a recent Sainsbury’s study of festive snacks… so the retailer has introduced a Crunch-o-meter.

In the study, crunchless crisps were followed by limp biscuits and crackers with no crack as snack food duds.

Cardiff, Edinburgh and Sheffield bucked the national trend, however, and abhorred soft biscuits above all else. They’re a bunch of tough (ginger) nuts up there.

The study also showed that, for one-third of consumers, quality nibbles were just as important as the Christmas dinner itself.

Sainsbury’s claims the Crunch-o-meter makes it the first supermarket to introduce a machine designed to ensure its own-brand snacks (crisps to crackers, peanuts to pretzels and everything in between) maintain the ideal level of bite.

The machine measures the force needed to break each product, and the reading (in grams) is then compared to a pre-set ‘crunch range’, which is determined by human tasters during product development.

The Crunch-o-meter can use a variety of probes, each designed for different products, textures, shapes and levels of crunch. For example, a 0.25inch diameter spherical probe is used on a special support rig to test the crispness of crisps. Adjustments need to be made for variables such as thickness and also for inclusions like chocolate chips or fruit to ensure an accurate reading is given.

Juliette Jahaj, head of analytical testing at Sainsbury’s, said: “Whether it’s turkey with all the trimmings or a bowl of crisps with the perfect crunch, our customers can rely on us for great-quality products.”