Apple Crumble

Apple crumble was a deliberate invention of World War II Britain. With pastry-making fats and refined flour strictly rationed from 1940, the Ministry of Food promoted crumble toppings as an economical substitute for the shortcrust lid of the traditional apple pie, since a rubble of flour, margarine or butter and sugar stretched scarce ingredients further. The dish is essentially unknown in British cookery books before 1940, and surges in print through the war decade. It calls specifically for the Bramley apple, a sharply acid cooking cultivar raised from a pip in Southwell, Nottinghamshire in 1809, whose flesh collapses to a fluffy puree on cooking while holding none of the sweetness of an eating apple. After the war the dish outlived austerity and became Britain's most-cooked home dessert, universally served with custard.

Soft, barely-sweet collapsing apple below a gritty, buttery, golden topping that is part biscuit, part rubble. The contrast of hot sour fruit and sweet crisp lid is the whole point; custard binds it.

The crumble topping is a short dough made by rubbing cold butter into self-raising flour with sugar, stopped well before it forms a paste so it stays in pea-sized lumps that bake into a rough, crunchy lid. Bramley apples are peeled, cored and sliced thick, tossed with a little sugar and sometimes cinnamon or cloves, and put raw into the dish, they cook down in the oven's heat while the topping crisps above. The dish is baked uncovered so the topping colours and crisps, typically 35 to 45 minutes at 180 degrees C. The success rests on the acid apple, a sweet dessert apple turns the dish to baby food, and on stopping the rub at the lump stage, an overworked paste bakes to a tough biscuit.