Buttercream or Fondant: Which Finish Should You Choose?

Buttercream is a soft icing made of whipped butter and sugar, spread onto the cake and worked smooth or textured with a palette knife. It stays soft, it cuts with the sponge, and it tastes of what it is made of.

Fondant — sugarpaste, to a baker — is a firm dough of sugar, water and glucose, rolled into a sheet and laid over the cake like a bedsheet over a table. It sets to a skin that takes any colour, any pattern and an edge you could cut paper on. Underneath it there is still buttercream or ganache, because something has to hold it on and fill the hollows.

So the difference is not icing against no icing. It is whether the outside of the cake is something to eat or something to look at, and fondant buys the second at the cost of the first.

Buttercream, and it is not close. It is butter and sugar whipped until it is light, and it belongs to the same mouthful as the sponge it sits on.

Fondant is sugar. It is pleasant in a thin layer and heavy in a thick one, and a good proportion of the people at any party will lift it off the slice and leave it on the plate. That is not a scandal — it is what fondant is for, and it has done its job by the time the cake is cut — but it is worth knowing before choosing it for a cake whose whole point is the eating.

A middle path exists and is ordered often: buttercream on the sides where the fork goes, fondant only where the design needs it, such as a modelled figure, a plaque or a flat panel for lettering.

Fondant, by a distance. A sheet laid over a cake and smoothed down gives a corner that stays a corner, a surface with no tool marks in it, and a colour that is identical all the way round. Anything that has to read as an object rather than a cake — a book, a box, a handbag, a tractor — is fondant, because buttercream will not hold a right angle for long in a warm room.

Buttercream has edges of its own kind. Smoothed, it gives a soft, almost chalky finish; textured, it holds the stripes of the palette knife; piped, it makes shells, ruffles and rosettes that fondant cannot do at all. A buttercream cake looks hand-made, and a fondant cake looks manufactured, in the good sense of the word.

No. Both are included in the price of the cake, which follows the size rather than the finish, as the table below sets out. What adds to a price is work on top of the finish — modelled figures, hand-made flowers, a printed topper, a second colour painted on by hand — and that is quoted with your design rather than taken from a list.

The one way the finish touches the price is indirectly: a design that needs fondant usually needs modelling as well, and that is the part that takes the hours.

Fondant, in the heat. Its skin is sugar and does not melt at the temperature of a party; buttercream is butter and softens, and a cake in a conservatory in July will lose its sharpness within the hour.

In the fridge it is the other way round. Fondant hates damp: a cake taken from a cold fridge into a warm room draws condensation onto the sugar and the surface goes tacky and loses its sheen, which is why a fondant cake is better left in a cool room than a cold one. Buttercream is happy in a fridge and simply needs an hour out of it before cutting, or it eats like cold butter.

The short version: fondant for a hot day, buttercream for a cake that will live in a fridge until it is wanted.

Buttercream, on more cakes than fondant and ganache put together, with fondant close behind it and ganache behind both. Those are counted from the photographs in the gallery rather than from memory, and the tally is printed on the drip cakes page, where it updates itself as the gallery grows.

The pattern behind the counts is simple enough. Children's cakes and anything that has to be a shape come back fondant; adult birthdays, weddings and anything meant to be eaten rather than admired come back buttercream; ganache turns up where somebody wanted a cake that is dark and sharp at once.