When a pastry case is filled with a custard or liquid filling, it is difficult to get the pastry cooked through by the time the filling is set. Pre-baking or ‘baking blind’ ensures that the pastry is cooked properly. Most, but not all, tarts call for this. Before baking blind, chill the pastry case for at least 30 minutes, to firm the butter so that the pastry will hold its shape. Heat the oven to 200°C/gas mark 6.
1. Make a cartouche of greaseproof paper, 8–10cm bigger than the tart tin. Scrunch it up, then unfold it and use to line the pastry case. Add a layer of dried beans or ceramic baking beans and fold the edge of the paper over the edge of the flan ring.
2. Bake for 15–20 minutes in the upper third of the oven until the sides are set. To check, remove from the oven and carefully pull the cartouche away from the pastry. If the pastry is holding up and looking less translucent and grey, remove the beans and gently tweak out the cartouche.
3. Return the pastry to a lower shelf of the oven for about 5 minutes, or until the base of the pastry looks dry and feels sandy to touch, but has not taken on any colour. Remove from the oven and allow to cool slightly before using.
A note on baking blind…
The dried (or special-purpose ceramic) beans help to support the sides and edges of the flan case and weigh down the base to prevent it from rising in the oven. Scrunching up the cartouche first, before unfolding it, helps to get it into the edges of the pastry case, ensuring the sides are well supported by the beans. If you are blind baking individual tart cases, use small dried beans or rice.
Repairing holes or cracks
If you are adding a liquid filling to a pastry case it must be watertight. After baking blind, check the pastry carefully for little holes at the edges or cracks up the sides, which can cause leakages. To repair these, soften a little of the leftover pastry in your fingers and plug the holes (as shown), or lay a strip of raw pastry over a crack, being very gentle with the pastry case. Return the repaired pastry to a lower shelf of the oven for 5–10 minutes to cook the raw pastry.
Using egg white
To provide a protective seal between the blind baked pastry and a wet filling, so the pastry won’t turn soggy, you can brush the pastry with lightly beaten egg white and return it to the oven for 3–4 minutes. This will also seal any very small holes.