Hello! My curd for the Bitter Orange Tart didn’t thicken. Even after 24 hours in the fridge it’s still very runny. Any tips on how to save it?
Nigella's Bitter Orange Tart (from SIMPLY NIGELLA) has a ginger biscuit crust that is filled with a creamy curd filling made from sharp Seville oranges. The filling is cooked in a saucepan on the hob or stove top. If the filling is too runny then it has not been cooked for long enough. The curd needs to be cooked until it has thickened enough to coat the back of a spoon wiith a fairly generous layer and when you draw your finger through the curd on the back of the spoon the line should hold and the curd should not flow back. If you are not sure and you have an instant read or digital thermometer then the curd should be cooked to at least 77°C/170°F.
If the curd has not set then you could try re-cooking it (once only), but if it is chilled then it can be difficult to reheat it evenly and it will take a long time over a low heat. You will also need to stir it constantly. The thin curd could be used as a sauce for ice cream or we would suggest using it for Nigella's Lemon Pavlova - putting the cream straight on to the meringue and spooning the thin curd over the top after and serving more alongside. As a very last resort you could try adding a leaf of gelatine (from a 100g UK supermarket package), though we have not tried this ourselves so can't guarantee the results. Heat the curd very gently until it feels warm to the touch and soak the gelatine in water until soft. Stir the gelatine into the warm curd until dissolved then press a piece of damp baking parchment (parchment paper) onto the surface again and cool and chill for about 20-30 minutes. When the curd has thickened pour it into the tart case and chill overnight. Please also note that the texture of the tart filling will be different and not as melt in the mouth as the original version.