Tarte aux Quetsches

Tarte aux quetsches is an Alsatian specialty built on the quetsche — the small oval purple plum of Alsace, a variety of Prunus domestica that ripens in late summer and early autumn. The tart belongs to the season of the plum harvest, when the fruit ripens across the Alsatian orchards. The preparation is rustic: a shortcrust or yeast-dough base is lined with halved quetsches, sometimes dusted with cinnamon-sugar, and baked until the crust is golden and the plums have collapsed into a soft, jammy layer. The tart is a specialty of the late-summer table and is closely associated with the Ruprechtsschwauf festival in Strasbourg in early autumn.

A wedge of tarte aux quetsches brings up a golden crust beneath a deep purple layer of collapsed plum halves, their juice staining the pastry. The plums are tart and jammy, balanced by the buttery crust and the warm spice of cinnamon if used. Eaten warm, the contrast of the sharp, fruity plum and the rich, sweet pastry is the point.

Tarte aux quetsches rests on the quetsche plum and a simple pastry base. The small oval plums — smaller and tarter than dessert plums, with a higher acidity and a denser flesh — are halved and laid cut-side up on the pastry; during baking, their cell walls break down and their juice is released, which the pastry base absorbs. The high acidity of the quetsche, balanced by the sugar and the cinnamon, is what gives the tart its characteristic sharp-sweet flavor. A pre-baked crust or a layer of ground almonds beneath the fruit prevents the wet plum juice from making the pastry soggy. The tart is baked until the crust is golden and the plums have collapsed.