I made a large batch of Egg-Custard Ice Cream and it curdled. The entire batch is now grainy but still tastes good. Can I use the curdled batch to make something else or fix it? Or should I dispose of it?
Nigella's Egg-Custard Ice Cream (from NIGELLA SUMMER) makes a custard with egg yolks, milk and cream. The custard is cooked over a low heat for about 10 minutes, until it thickens slightly. All egg-based custards can curdle if they are cooked for too long, or at a high temperature. A low temperature and constant stirring are important to prevent the custard from curdling. Nigella also suggests that you half fill the sink with cold water so that if it looks as if the custard is starting to curdle you can dip the base of the pan into the water and whisk vigorously, to cool the custard quickly.
The grainy texture is caused by the proteins in the egg yolk clumping together. The custard is still safe to eat, but the texture can be unpalatable. Sometimes it is possible to rescue a curdled custard enough so that it can be used as a base for ice cream, it depends how badly the custard has curdled. You can strain the custard though a fine mesh strainer to help get a smoother texture and if the strained mixture is acceptable to you then you can chill and churn it for ice cream. If there are larger grains in the custard then pulse it a couple of times with a hand blender before straining (but not a blender or food processor as these just turn the mixture frothy). However if the strained custard is very thin or still grainy then you may prefer to discard it. Nigella also has a wide selection of no-churn ice creams that are very easy to make and do not require a custard base. We would suggest trying the One-Step No-Churn Coffee Ice Cream, No-Churn Bitter Orange Ice Cream or No-Churn Chestnut Ice Cream.