Sunday Baking: Meringue Buttercream again

So, last week's chocolate mojito cupcakes went down OK. They were tasty, and everyone at work said they were nice, but I still wasn't happy with that meringue buttercream. It still tasted more sort of greasy than like sweet icing. I chatted with my friend Caroline about it who said that she thought meringue buttercream was meant to sort of set, like meringue, and that perhaps I needed to beat it for longer. I went and looked at some blogs online, as well. And I had another go.

It was more successful this time. Here's my recipe -
3 egg whites
180g soft light brown sugar
250g unsalted butter
Zest of one lime
Generous tbsp of rum

I heated the egg whites with the sugar in the Kenwood bowl over a pan of water, instead of over the direct heat, as the recipe I used last week told me. The mixture was extremely dark and I felt very worried; I wanted to use brown sugar for a more authentic mojito taste (I spent most of Friday night testing mojitos in my kitchen to find the perfect flavour; unfortunately I can't remember the combinations after the first three...odd) but I didn't bargain on it going the colour of mud.

I then transferred the bowl to the mixer and set it whisking. I whisked for much longer than 5 minutes. I was aiming for 10. The mixture quite quickly lightened until it was a very pale caramel colour - perfect. I whisked on. By the time I eventually stopped, it was tasty enough to eat on its own. Mmmmm.

I added the lime. I cut the butter into 10 cubes and started adding them; and this time, although the butter had been out of the fridge overnight to soften, I put it back in the fridge for half an hour before I needed it to firm it back up again. I added 5 cubes of butter, beating in between each one, then scraped down and added the rum, then 2 more cubes of butter. I tasted. "Ah ha," I exclaimed, "this is how it should taste!" It was very yummy - light, sweet, not greasy.

I started mixing again and added the final 3 butter cubes. This may have been an error. The mixture started to look distinctly curdled but I remembered the blogs and kept whisking and eventually it came back together. The final product is good, but I think it would have been even better if I had stopped before adding the final 3 butter cubes. It's light and fluffy and sweet and rum flavoured; but it has an edge of greasiness.

I don't think it is supposed to set like meringue, though. I'm going to ignore that portion of the advice.

Oh, and if you're wondering about the mint, I hit upon the idea of making the chocolate muffins with mint chocolate to get the flavour in there instead. It's a bit strong and lacking that fresh-garden-mint flavour but it made for a much easier meringue buttercream experience.