Double cream is a very thick dairy cream often referred to as heavy cream in North America. Inevitably, when you need light cream, you have heavy cream, and vice versa.
With the right method, you can make double cream at home that contains at least 48 percent milk fat content. The ability to substitute single cream for double (heavy/whipping) cream in a recipe really very much depends on the recipe itself. Unfortunately if it is a recipe that requires the cream to be whipped then usually it is not possible as single cream does not have a high enough fat content to whip - it will not hold any air but will eventually turn into butter if you keep whipping it.
Our answer. It is not possible to turn single cream into double cream. The only way I can think of would be to add more fat to the cream, as double cream (heavy cream) has a higher fat content than single cream. Single cream can, however, be turned into Chantilly cream. Although there's no way to transform light cream into heavy cream, you can dilute heavy cream to make it lighter.
This works especially well when you need the cream for coffee or pouring over fruit or a dessert, such as apple crisp. This is because the butterfat content of single cream is too low.