You can of course use margarine, and if you want a really white - no buttery yellow undertones - icing, then you use a pure white margarine like Wooden Spoon.
However, I have to tell you, I may have been confused about whether I was Team Jacob or Team Edward, but when it comes to Team Butter vs. Team Margarine, it's butter, butter, butter for me!
Margarine is just too synthetically greasy, I can't bear the thought of eating it, or even worse, feeding it to my children, so I opt for butter as our artery-clogging saturated fat of choice!
Whichever you use (and I do believe butter produces a superior result), the ratio is 2 parts icing sugar, to 1 part butter / margarine, ie 1kg icing sugar : 500g butter.
The trick is then to beat, beat, beat the butter /margarine first (especially if you are using Wooden Spoon White marge. ) until it is pale and smooth. (Start with the butter/ marge at room temp.)
...see how smooth the butter is on the mixer's paddle.
Then add all the sifted icing sugar, and beat until smooth, and fluffy.
If it is too stiff, you can add a tablespoon of milk.
You can add any flavouring you choose, but it is always a good idea to have vanilla as your base, and then add other flavours onto that. And of course colours.
If you use butter, the creamy yellow colour does affect the colouring process (blue looks aqua, instead of true blue, etc.) So, if you want white/ pink/ blue without yellow undertones, go with the white margarine, and use caramel essence for flavour, as it doesn't add any colour to the icing the way vanilla extract may.
|Wedding dress cupcakes, with butter icing|