I tried Nigella's White Chocolate Mint Mousse recipe as featured on her show on the Food Network. I wasn't sure what cream to use as it just says heavy cream. I used double fresh cream and had to whisk the cream, egg and peppermint extract for ages to get it heavy. As soon as I added the melted white chocolate in the whole mixture curdled. It looks horrid and was wondering if you knew what went wrong? What cream am I meant to use? Whipping cream, the really heavy double cream that's already quite thick or what I used the double cream that's still liquid?
Nigella's White Chocolate Mint Mousse (from Nigella Express) is made from a mixture of whipped egg whites and cream, mixed with melted white chocolate. We are not sure exactly which country you are in as the Food Network broadcasts in several countries but we suspect that the type of cream used could have been the cause of the problem. The name and definitions of cream can vary between countries.
You want to use a cream that will whip fairly easily, and preferably has a fat content of 35% or more. In the US this will be heavy cream but in other countries it may be known as whipping cream. You also need to look for regular pasteurized cream, as UHT cream does not whip as well. If it took a long time for the cream and egg whites to whisk together then it could be that folding in the chocolate afterwards was just too much and the mixture curdled through over-whipping. You may also find it helpful to firstly whisk the egg whites to soft peaks, then whisk the cream and fold these two together before mixing this with the melted chocolate.