I would like to fill mini sweet tartlets with cream and fruit. I experimented with natural yogurt and the pastry cases were soggy in a couple of hours. I want to make and fill with creme patissiere. Will the same thing happen if I assemble them before a party? If so how do they sell them ready assembled in supermarkets?! Some recipes for creme patissiere use flour AND cornflour. Nigella in Domestic Goddess only uses flour and she uses double cream and milk. Some recipes only use milk. Please help with my confusion! Thank you . Deane-Mae
Creme patissiere, also known as pastry cream and sometimes as confectioners' custard, can be made in several ways. It always has eggs and flour or cornflour as these act as thickeners but can be made with milk or a combination of milk and cream. Some recipes make a custard and use it when cooled.Some recipes make a very thick base which is then cooled and mixed with whipped cream or even incorporate whisked egg whites (usually called creme Chiboust). Using cornflour will generally give a slightly thicker custard and using cream will make the custard richer.
As the custard is thickened it will not make a pastry case go soggy as quickly as a wet ingredient such as yogurt, but the pastry case will eventually soften over an extended period of time. You can also help to keep the pastry crisp by adding a sealing layer which will slow down the seeping of any moisture into the pastry. The most effective sealer is beaten egg - brush the pastry cases with a little beaten egg before they go in the oven and bake as usual. If you are baking a larger pastry case blind (filled with baking beans) then wait for the pastry case to bake and set, remove the baking beans and brush the egg carefully to the surface of the pastry then return the pastry case to the oven to bake for a further 5-10 minutes, until the base is dry and golden. Another way to seal the base of a sweet pastry case is to scatter some very finely chopped chocolate over the base of the hot pastry case then spread it out into a thin layer as it melts. Leave to cool and set.
A tart filled with creme patissiere should stay crisp for 4-6 hours but bear in mind that creme patissiere contains lightly cooked eggs and so should not stand at room temperature for too long (particularly in warm weather). We suggest you fill the tarts as near as possible to serving. For small tarts it may be easier and quicker to pipe the creme patissiere into the pastry cases. You can do this with a pastry bag and medium plain nozzle or fill a robust plastic food bag (such as a freezer bag) with the creme patissiere, snip off one corner and use this as a piping bag instead.