There is much debate about how cream should be classified, especially when it comes in so many forms. When testing and developing our recipes at Gourmet Traveller, we like to place creams into four categories; pouring cream, heavy cream (45%), double cream and thickened cream. Most creams are likely to be differentiated by their fat content, except thickened cream which always has the addition of gelatine to act as a stabiliser. The higher the fat content of a cream, the thicker the consistency.
When we specify pouring cream - which has a fat content of only 35% and the lowest cream fat to milk ratio - it is of a pouring consistency. Heavy cream, which we also note as being 45%, is what many chefs call double cream but, as there is only one brand that sell this cream commercially, we call it heavy cream (45%).
Just to confuse the situation further, the reason we state heavy cream and then put the fat content only on this cream is that it is packaged as pure cream, which some 35% creams are also sold as. And in reality, pure cream really should be double cream since it has the highest fat percentage and is therefore the purest.
Double cream has a fat percentage of anything higher than 50% and is usually a very thick cream, which can only be scooped. It is best used to serve as an accompaniment and not necessarily good to cook with. The cream fat is usually marked on the ingredient section of the packaged label of all creams, and this is the best guide to go by instead of what each company specifies their cream to be.