Icing without icing sugar
Icing sugar is only sugar ground fine with a little starch. How to make it yourself, and the icings that never needed it, including egg-free ones.
It is four in the afternoon, the cake is baked, and there is no icing sugar left. The question is not whether you can do without, but which of the three routes you take: remake it, work around it, or change icing altogether.
What icing sugar actually is
Granulated sugar ground very fine, with about 3 % starch (maize or rice) added to stop it caking.
Two practical consequences. First, you can remake it at home, since it is only a matter of grinding. Second, the starch is not just an anti-caking agent: it slightly thickens the icing. An icing made with home-ground sugar, with no starch, will be a little runnier for the same weight.
Making it yourself
In a blender or coffee grinder. 100 g of granulated sugar, a level teaspoon of cornstarch, blitzed for two minutes in 20-second bursts. Sugar heats up and clumps if you run it continuously.
The result is never as fine as industrial icing sugar, which is milled by far more powerful machines. It stays slightly gritty. In an icing that is imperceptible once dissolved. For dusting a cake, it shows.
What does not work: a standard smoothie blender, whose blades sit too high and too wide, simply spins around the sugar. You need a narrow jug.
The icings that never needed icing sugar
This is often the better way out. Three classic icings contain none at all.
| Icing | Composition | Texture |
|---|---|---|
| Ganache | Chocolate + cream, equal weights | Glossy, soft, sets in 2 h |
| Sugar-syrup glaze | Granulated sugar + water, cooked to 110 °C | Thin, crisp, white |
| Salted caramel | Sugar + cream + butter | Thick, flowing, never fully hard |
Ganache is the simplest: 100 g of chocolate, 100 g of hot cream, poured in three goes and stirred from the centre. It is the same mechanism as in a no-bake chocolate cake, where set chocolate holds everything up. It covers a whole cake and needs no added sugar.
The sugar-syrup glaze needs a thermometer. Cook 100 g of sugar with 40 ml of water to 110 °C, let it cool to 60 °C, then beat until it whitens and turns opaque. It is the closest thing visually to royal icing.
The egg-free case
Classic royal icing relies on egg white, which coagulates slightly and gives the brittle set. Without egg, two substitutes genuinely work.
Aquafaba, the liquid from a tin of chickpeas. It whips like a white, in the same proportion: 30 ml replaces one egg white. It is the most faithful substitute, including for shine. It needs about three minutes more whipping.
Powdered egg white, rehydrated, if the aim was only to avoid raw egg rather than egg altogether.
With neither of them, a mix of icing sugar and lemon juice gives a decent icing, but it stays slightly tacky to the touch even hours later. It is no good for stacking or wrapping biscuits, which matters if you are icing cookies destined for a tin.
The liquid-to-sugar ratio, which decides everything
For any sugar-based icing, this ratio is what governs the result.
- Pouring icing, which flows and levels itself: 15 ml of liquid per 100 g of sugar.
- Piping icing, which holds its shape: 8 to 10 ml per 100 g.
- Dipping icing, for biscuits: 20 ml per 100 g.
Always add the liquid to the sugar, drop by drop, never the other way round. A runny icing is fixed by adding sugar, but you quickly double the amount you planned without noticing.
Frequently asked questions
Does home-made icing sugar keep? A few weeks in an airtight jar, but it takes up moisture faster than the industrial kind and forms blocks. Making it as you need it is simpler.
Can I use brown sugar? For a white icing, no. For a caramel-style icing or a loaf cake glaze, yes, ground the same way. The molasses it contains makes it damper, so reduce the liquid by 20 %.
Why does my icing stay translucent? It lacks starch or air. Icing turns opaque by whitening, that is, by taking in bubbles from the whisk. Two more minutes of beating solves it in most cases.
How long does it take to dry? A water icing, two to four hours in the open air. An aquafaba or egg-white icing, one hour. A ganache, two hours in the fridge. None of them dries properly in a humid kitchen straight after baking, nor on a cake still warm from a pan cooking.