A food writer's quest to recreate the perfect school dinner crumble has uncovered a surprising tip from Nigella Lawson: freezing the topping before baking. The discovery comes after years of failed attempts to match the comforting pudding served by 'Dot the dinner lady' at school.
Research into the dish's history reveals its humble origins. The first printed mention of crumble appears in the 1950 edition of Fanny Farmer's Boston Cookbook, an American publication. According to the Oxford Companion to Food, crumble likely originated during the Second World War as a quicker, cheaper alternative to pastry, using whatever fat was available.
Testing began with a basic recipe from Nigel Slater's Real Fast Puddings, containing just fruit, flour, sugar and butter. Adding a little water to the mixture created 'small pebbles' that produced a crisp topping, though the writer preferred more crunch over the 'soggy bit underneath'.
Nigella Lawson's method in How to Eat recommends giving the rubbed-in mixture a 'quick blast in the deep-freeze' before baking. The theory is that chilling slows the melting of butter, helping the crumble retain its pebbly shape. A side-by-side test confirmed that the frozen mixture yielded more lumps and bumps than the one cooked immediately.
Lawson also advocates rubbing the butter in by hand rather than using a food processor, claiming it produces a 'more gratifyingly nubbly crumble'. The processor can make crumbs so fine that the result becomes cakey rather than crumbly. For those short on time, the mixture can simply be stored in the fridge until ready to use.
