Swiss Meringue Buttercream

There's nothing worse than a shabby dry cupcake flooded with tooth-rottingly sweet icing trying to pass itself off as a fine example of cake.  And believe me, I have eaten some pretty horrendous cupcakes in my time - two of which were in very well known bakeries in New York.  They were so bad, we chucked them in the bin, which goes against my waste not, want not philosophy, and left a really bad taste in our mouths.

So, what do you do when faced with something pretty on the outside but mediocre within?  Well, you go and make a much nicer version yourself!.  This sweet but light Swiss Meringue Buttercream icing on top of my Red Velvet Cupcakes combines the best of glossy meringue and the richness of buttercream to create a really stable, delicious icing to grace any cupcake with elegance and grace.  Two things you need to bear in mind though : it takes ages to make, so clear your afternoon and use a food mixer unless you want biceps like a WWF contestant!

Photo by Kerrie Walsh

Swiss Meringue Buttercream (SMB for short)

10 Egg Whites (or 300g of Pasteurised Egg Whites in a Carton)
500g Sugar
675g Butter, cut into cubes & halfway between fridge cold & room temperature
25ml Vanilla Extract

Boil a kettle of water and put about 2 inches worth into your biggest pot.  Place on the hob & turn the heat down to the lowest simmer.  Make sure your food mixer bowl is spotlessly clean - if in doubt, give it a wipe with some kitchen paper and vinegar or lemon juice - and place into the pot to form a bain marie,

Add the egg whites and sugar and whisk gently but continuously for about 5 minutes until all of the sugar has completely dissolved.  Remove the bowl from the water & wipe the outside with a teatowel, so you don't get your food mixer wet.

Using the balloon whisk, beat on a slow speed (2-3) until the meringue is glossy, very thick and the base of the bowl is slightly warm.  How quickly this happens depends on your bowl : if it's plastic, about 10 minutes but up to 30 minutes for metal.  This is when you will fall on your knees and give thanks that you're using a machine and not doing this by hand!

Once the bowl has cooled, swap the balloon whisk for the paddle beater and start adding the cubes of butter, one at a time.  Don't try to add more and beat faster... it doesn't work like that & this will take about 10-15 minutes.  Once all the butter has been incorporated, add the vanilla extract and beat for another minute.  If you want it to look very vanilla-y, use vanilla bean paste.  Also, if you want to colour or flavour the SMB, now is the time to add gel colours or fruit puree/melted chocolate.

The finished SMB pipes beautifully, goes on smoothly with a spatula and is really quite the most perfect cupcake icing in existence.  If you're serving them in warm weather or prefer a firmer icing, give them 30 minutes in the fridge.

If you've any leftover SMB, put it into a sealed container and stick it in the freezer - it's fine for 2-3 months.  Just thaw it & give it a good whisk before you use it.