Can Greek yogurt be substituted for the sour cream in the topping for Nigella's London Cheesecake? Thanks
Nigella's London Cheesecake (from Domestic Goddess and on the Nigella website) has a cheesecake batter made from cream cheese and in the final stages of baking a mixture of sliightly sweetened sour cream is spread over the top and baked until just set. Whilst Greek yogurt can be a good alternative to sour cream in dips and cold sauces, and in some instances in baking, we suspect that for the cheesecake topping yogurt would not be particularly good.
Sour cream has a fat content of about 20% whilst full fat (whole milk) Greek yogurt usually has a fat content of about 5% (though some can be as high as 10%). The problem with the lower fat content is that the yogurt is less stable than sour cream and can curdle if it is heated excessively. The water bath used for cooking the cheesecake does make the cooking method slightly gentler but we would be worried that the yogurt would heat too much and curdle, leaving watery liquid and small lumps of yogurt protien on the surface of the cheesecake. It would be safe to eat but would look unattractive and may not be particularly palatable.