Royal icing vs. rolled fondant - Getting ready for Christmas

Traditionally speaking, British Christmas cakes and wedding cakes are heavy, rich fruit cakes that are made weeks or months in advance of the date they are needed, matured and 'fed' regularly with brandy, then covered in a 3 mm or so layer of marzipan and finished off with a hard, white layer of royal icing.

These days if you search online for information about royal icing, you're more likely to find yourself on sites discussing decorating cookies, or perhaps creating lasting decorations. The Wilton site even goes as far as to recommend royal icing is not used as a cake covering. Certainly, the sometimes impractically hard covering created by royal icing would be a strange match for a butter cake or chocolate cake, but I do think it has a place still for fruit cakes.

This year, partly as preparation for making my sister's wedding cake (congrats!) next year, and partly to do the kind of side-by-side taste test I love so much, I made a few Christmas cakes for a rolled fondant vs. royal icing showdown.

Fondant is extremely easy to work with - it stores well if you don't use all of it at once, is easy to cut slices of once it's on a cake, and you can get creative with colours and make all kinds of decorations. The downside for me is that, depending what brand you use, there are a bunch of things in there I wouldn't usually choose to eat, like shortening, thickening agents, emulsifiers, preservatives etc. I have also seen recipes for home-made fondants that include stabilised cream and butter rather than shortening, but I wonder how they would hold up under heat.. more experiments ahead!

Royal icing by contrast is traditionally made with just egg whites and powdered sugar. Some recipes also include the additive of food-grade glycerine (a sugar alcohol) to stop it from drying too hard, others add lemon juice. Many modern British recipes suggest using powdered egg white, or pasturised egg whites instead of raw, to remove any risk of salmonella.

Smooth, but slightly pocked royal icing surface

Slightly bobbly surface of rolled fondant icing

Royal icing can create sharper lines on your cake than fondant, it's also a brighter white than most types of fondant and can hide the lumps and bumps of the fruit cake better, though there are ways to improve the bobbly appearance even when working in fondant. A downside to royal icing as a fruit cake covering is that it's not easy to get a neat cut - even with glycerine it dries very hard! The layer of icing frequently cracks as you cut into the cake, and shatters either side of the knife as you cut down.

Considering its use in traditional wedding cakes, and the common ritual cutting of the cake together, this is a fairly big consideration - you don't want the happy couple giving the impression they can't achieve things together by failing to cut into the cake :) I've found that using glycerine, whipping up the icing to stiff peaks and building the icing up in thin layers on the cake, smoothing and sanding between each layer creates a more powdery (rather than concrete!) covering that a sharp, thin knife can handle relatively easily. I'm still experimenting here.

Having cut these cakes in half I wrapped them up, sealed them in a cake tin and stowed them in my check-in luggage. In preparation for the wedding I also need to discover how well these coverings travel. Indeed, and whether the purported similarity of fondant to Semtex means my case arrives in the UK at all.. :) I'm currently on the plane and shall report back. (Edit: travel success! They both arrived in good condition and were not exploded by airport security.)

In these tests, for elegance and taste the royal icing won hands down but the fondant being easy and practical means it has a lot going for it. I kinda hope my sis choses the royal icing for her wedding cake, but we'll see..!