As it was the birthday of my father in law to be, I was asked to whip up a batch of coffee cupcakes to celebrate his 53rd year. Pretty basic and as I've been making a lot of cupcakes recently (it seems I'm baking for pretty much everyones birthday at the moment) I thought I'd try something different. I've always fancied the sound of Swiss Meringue Butter Cream but never got round to trying it, so today was to be the day. A little bit fussier than normal butter cream the SMBC requires constant whisking over a double boiler to thicken up the egg whites, but boy is it worth the extra effort. So silky, so creamy, the most sophisticated frosting I have ever experienced.
Recipe for Coffee Swiss Meringue Butter Cream (from how to eat a cupcake)
170g caster sugar
3 egg whites
1/8 tsp salt
170g unsalted butter, at room temperature
1 tbsp hot water
1 1/2 tsp instant coffee
Put sugar, egg whites and salt into the top of a double boiler over a pan of simmering water. Whisking constantly, cook until sugar has dissolved and mixture is warm (about 160 degrees). Pour heated egg whites into the bowl of an electric mixer fitted with the whisk attachment. Beat egg white mixture on high speed until it forms stiff (but not dry) peaks. Continue beating until fluffy and cooled, about 7 minutes total. Switch to the paddle attachment. With mixer on medium-low, add butter two tablespoons at a time, beating well after each addition. Increase speed to medium-high; continue beating until frosting appears thick, about 3 minutes. Meanwhile, stir 1 1/2 tsp instant coffee into 1 tbsp hot water until dissolved, then put it in the fridge or freezer until it comes down to room temperature. Reduce mixer speed to low and add coffee mixture. Continue beating 1 minute to reduce air bubbles.