Sugar High Friday – Grapefruit Curd filled Cupcakes with Champagne Meringue Frosting

Update: Part II of my Sugar High Friday post is here. I didn't think it merited it's own entry over at Tartlette.

This post is a little on the long side, but if you're going to make the recipe, it's worth reading what's written in the curd and frosting sections before the recipes.

I’ve decided that it’s time my blog started to get out into the world, and expand beyond its loyal reader base of 2. Getting a mention on Cupcakes Take the Cake last week was a big help, but I’ve also decided I’m going to start entering some blogging events. To that end I decided to submit an entry to this month’s Sugar High Friday, being hosted by Tartlette. The theme for the month is citrus, and of course I decided to make a cupcake. I do make other things, but I know where my strengths lie.

This cupcake was sort of an odd choice for me, mostly because I don’t like either grapefruit or champagne. This also makes me tragically unqualified to evaluate how these cupcakes taste, since what I would like in these flavors is different from what most people would. Fortunately, I do have friends who are happy to taste test them for me. I started by deciding on grapefruit, because I thought it might be something that other bloggers were less likely to use in their submissions. From there I decided that Champagne would make a nice addition, the question was how to add it. A cupcake filled with grapefruit curd was easy (in principle), but champagne frosting was another matter. Adding any significant quantity of it to a buttercream, meringue, or pretty much anything else I could think of would just lead to a runny frosting. I could use champagne flavoring, but I have no idea where to get that. I was pondering this problem for several days when the answer struck me: Powdered Egg white! Instead of reconstituting it with water, I could reconstitute it with champagne. I had no idea if this would work, and found no websites that suggested anything about it, so I figured I would go ahead and try. The results were surprisingly successful. I’ll write more about it when I get to the frosting section below, but I thought it deserved a mention in the intro.

I used a chiffon cake as the base for this cupcake. I though the light airyness of it would complement the champagne well. I tried both a chiffon with champagne and one with grapefruit juice, and I think the one with grapefruit juice tasted better. If you decide to use champagne instead or in combination with the grapefruit juice it doesn’t matter, you just want the same volume of liquid.

Grapefruit Chiffon Cupcake

Makes 20 cupcakes

1 cups + 2 Tbs sifted cake flour
3/4 cups sugar
1 ½ tsp baking powder
¼ tsp salt
3/8 cup grapefruit juice
7 ½ tsp vegetable oil (2 Tbs + 1 ½ tsp)
¾ tsp vanilla extract
4 eggs, separated

1. Preheat the oven to 325 degrees. Whisk together the flour, all but a tablespoon of the sugar, the baking powder, and the salt in a bowl

2. In a separate bowl, whisk together the grapefruit juice, vegetable oil, vanilla extract, and egg yolks

3. Pour the wet ingredients into the try ingredients and whisk until smooth

4. In another bowl beat the egg whites with an electric mixer until they begin to become frothy. Add the sugar, and continue beating until the whites just reach stiff peaks

5. stir ¼ of the egg whites into the batter until thoroughly mixed. Gently fold the rest of the egg whites into the batter until there are no more streaks.

6. Fill cupcake tins with ¼ cup measurer, bake for about 14 minutes, or until a tester comes out clean.

Grapefruit Curd

Makes a whole lot, way more than necessary to fill the cupcakes (It has been pointed out to me you can never really have TOO much fruit curd)

This recipe was a pain. I started out using the citrus curd recipe listed on Cupcake Bakeshop. However, after 4 minutes, my curd hadn’t thickened at all. Stirring all the while, I tried looking up another recipe. It told me that my curd needed to get up to about 160 degrees and that it should have the thickness of sour cream. So I stuck my candy thermometer in the mix and let it get to 160. It wasn’t the thickness of sour cream, but it had thickened, and that was good enough for me. I took it off the heat, added the butter, and put it in the fridge over night. I then went and looked up egg creams in On Food and Cooking, and discovered that the proper temperature for an egg cream is 180 degrees. Wikipedia’s recipe for lemon curd confirmed this. I went to check on my curd in the morning, and sure enough it had thickened, but not nearly enough. I put it on the stove again and threw caution to the wind, turning the heat up to medium high. This time I brought it to 180 degrees, took it off the heat, and stuck it into the fridge. Came back a few hours later to check on it, and sure enough it had thickened, basically into glue. It was delicious glue, but not something you would want to find in the middle of a cupcake. Not wanting to make another batch, and needing significantly more volume anyway (there was no way it was going to fill 20 cupcakes), I decided to go back to the original method and add whipped cream to it. I whipped up some cream with a little powdered sugar, and added the grapefruit curd. It whipped together pretty well, but was not grape-fruity enough anymore, so I added three tablespoons of grapefruit juice. That ended up coming out pretty well, but I now had way more than I needed.

Anyway, the moral of the story is that if you have your own preferred recipe, use it. None the less I will print mine here if someone else thinks they might have better luck with it

4 egg yolks
2/3 cup of sugar
8 Tbs Grapefruit juice - divided
5 Tbs unsalted butter, cut into small pieces
1 Cup whipping cream
1 Tbs Powdered Sugar
1 drop red food coloring (optional)

1. In a heavy bottomed sauce pan over medium heat, mix egg yolks, sugar, and 5 Tbs of the grapefruit juice. Stir the mixture constantly, until it reaches between 175 and 180 degrees, or coats the back of a spoon well

2. Remove from heat and pour into a bowl. Add the butter a few pieces at a time, and mix until combined.

3. Press a layer of plastic wrap directly onto the curd to prevent a skin from forming. Put in the fridge.

4. Once curd is thoroughly chilled, whip up one cup of whipping cream with the powdered sugar until stiff peaks form. Add the curd to the bowl and keep whipping until mixed. Add the remaining 3 Tbs of grapefruit juice, or as much as suits your tastes. Add the food coloring to make the mixture pink, so it looks grapefruity.

Champagne Meringue Frosting

Makes at least enough for 20 cupcakes

This frosting is interesting. I’ve never used egg white powder before, but this couldn’t be done with regular egg whites. The frosting is light and fluffy like a meringue, and tastes like champagne, because that’s what’s in it. I originally made the frosting the night before making the cupcakes, and in the morning discovered that the meringue had wept, and lost its stiffness. A few minutes of beating it on high speed and it was back where I needed it, but I noticed that a few hours later it had fallen again, though it hadn’t wept. My recommendation is that you whip this up to stiff peaks into a bowl ahead of time, but don’t put it onto the cupcakes until just before serving. Then whip the whites back to stiff peaks, and apply to the cupcakes.

1 Pkg powdered egg whites (the package I used says it contains 24 grams)
¾ cup Extra -dry champagne (you’re going to be adding sugar, don’t use sweet)
5 Tbs superfine (castor) sugar.

1. Measure ¾ of champagne (this can be tricky because of the foam). Pour the egg white powder into a large bowl, and add the champagne. Use an electric mixer at high speed to whip the mixture until it becomes foamy. Add the sugar one Tbs at a time and beat until the meringue forms stiff peaks.

Assembly

1. Use the cone method (detailed in previous posts) to fill the cupcakes with grapefruit curd.

2. Use a soup spoon to pile a mound of meringue onto the cupcake. Then use a regular tablespoon to pull the meringue out to make it interesting

3. Use a cooking torch to quickly toast the meringue, just enough so that it starts to brown. It should smell a little like roasting marshmallows as you do it.