Scientists crack the crumbly biscuit riddle

A crumbly conundrum has been solved by scientists investigating why biscuits crack up so often. Contrary to what most shoppers think, it has little to do with the way they are packaged and transported.

A crumbly conundrum has been solved by scientists investigating why biscuits crack up so often. Contrary to what most shoppers think, it has little to do with the way they are packaged and transported.

Physicists at the University of Loughborough, Leicestershire, ran laser tests, which showed that biscuits often develop "fault lines" a few hours after baking. As the biscuit cools, it picks up moisture around the rim, which causes it to expand.

At the same time, moisture at the centre makes the biscuit contract. The difference results in a build-up of strain forces, which pull the biscuit apart. Cracks appear that weaken the biscuit, so it easily breaks apart when handled, moved or packaged.

Manufacturers tackle the problem by removing offending products before they reach consumers. But many cracked biscuits still end up in packets of biscuits sold in corner shops and supermarkets.

Qasim Saleem, a doctoral student who led the research, said in the journal Measurement, Science and Technology: "This will help manufacturers produce the perfect biscuit."