Blueberry Lemon Mini Cupcakes

Lilac and yellow is a graceful color pair such as the duo blueberry and lemon together in flavor. Perhaps they are one of my favorite combinations, and they were my inspiration for these mini cupcakes that I prepared for you, my dears.  I made this cake recipe for the first time a while ago using lemon brigadeiro and blueberry jam as filling, and I loved it. This time I made a miniature version with lemon and blueberry buttercream colored with natural colors.  I have noticed I've got migraine every time I eat a food that contains food coloring. So I decided to use the natural colors of the ingredients instead of synthetic food dyes.

The pigment that gives blueberry the blue hue is called anthocyanin. It’s also the substance with antioxidant activity that helps to prevent some diseases. This wonderful pigment is also a good option on cake decoration.  I prepared blueberry jam to get the lilac color for gum paste and the purple for  buttercream. Blueberries, such as apples, have some substances (enzymes) that react with oxygen when they are cut, producing a brown color on the surface. So if you cook them, or add sometimes acid (like lemon juice), you will avoid the oxygen contact and prevent the color change. On my first try, I just blended fresh blueberries, but they turned in a brown pure. So I made a blueberry jam to preserve the color and to intensify the flavor.

I cooked some blueberries with water, lemon juice and sugar until thick consistency. Then I added some of this jam to buttercream and I got a beautiful purple color. To make the buttercream roses I followed this tutorial using the Wilton's tip 104. For quite some time I have desired to try this technique. I have to say that I’m in loving with it.  How lovely are theses roses?

To tint the gum paste, I added small quantities of jam until the desire lilac shade. With this lilac gum paste I made little roses to decorate the cupcakes with lemon buttercream. I’m so happy how jam and gum paste worked well. I became even happier when I found lilac roses with the same shade at the grocery store. To the lemon buttercream, I prepared first lemon custard with egg yolks, cream, gelatin, lemon and sugar. Then I incorporated it on the buttercream. The yellow of the egg yolks was the pigment here, and it turned into a pastel yellow with the white of the buttercream.

I do really love these mini cupcakes. They are delicate and adorable. They are just as good as they look.

Blueberry Lemon Mini Cupcakes

Cupcakes

(adapted from Martha Stewart)

yield: about 10 cupcakes or 20 mini cupcakes

3/4 cup cake flour (not self-rising), sifted

1/2 tablespoon baking powder

1/4 teaspoon salt

1/4 cup plus 1 tablespoons granulated sugar

1/4 cup skim milk

3 Tb canola oil

1  teaspoon pure vanilla extract

Finely grated zest of 1 lemon, plus 1/2 teaspoon fresh lemon juice

2 large egg whites, room temperature

1 cup fresh Blueberries

Preheat oven to 350 degrees. Make the cake: Sift together flour, baking powder, and salt into a medium bowl; set aside. Whisk together half sugar, the milk, oil, vanilla, lemon zest, and lemon juice in a large bowl; set aside.

Put egg whites into the bowl of an electric mixer fitted with the whisk attachment. Beat on medium speed until foamy. Raise speed to medium-high. Gradually add remaining sugar, beating until stiff peaks form.

Add half of the flour mixture to the milk mixture; whisk until smooth. Fold in remaining flour mixture, alternating with the egg white mixture. Add blueberries. Fill each cupcake line full with batter.Bake, rotating pan halfway through, until a cake tester inserted into centers comes out clean, about 10-15 minutes. Let cool on a wire rack. 

Vanilla Buttercream

(from the book Miette)

yield: 6 cups

Note: For this cupcake recipe you will use about 2 cups.

2 cups (14 ounces) sugar

1/3 cup water

5 large egg whites

1 teaspoon cream of tartar

3 cups (1 1/2 pounds) unsalted butter, at room temperature.

2 tablespoons vanilla extract

In a small saucepan over medium heat, combine the sugar and water. Clip a candy thermometer to the side of the pan. Cook the mixture until it reaches 248 degrees F, 5 to 10 minutes, keeping a constant eye on it.

Meanwhile, combine the egg whites and cream of tartar in the bowl of a stand mixer fitted with whisk attachment.

As soon as the sugar syrup reaches 248 degrees F, immediately pour it into a heat-proof measurer. Pour a few tablespoons into the whites, away from the whisk, so the hot syrup doesn't splash, and whisk on medium speed for a few seconds. Be careful as the syrup is very hot. Pour in a little more syrup and whisk for a few seconds, until incorporated. Repeat until all the syrup has been added. Raise the speed to high and continue to whisk until the mixture cools to room temperature, 70 to 75 degrees F, 5 to 10 minutes.

Only when the meringue is cool enough should you begin adding the butter. Reduce the speed to medium. With the mixer running, drop in the butter, 1 tablespoon at a time, waiting until each is incorporated before adding another. The mixture may deflate and begin to look curdle. Raise the speed to high and continue to add to add tablespoon-size pieces of butter, making sure each is completely combined before adding more. When all of the butter has been added, the frosting should be smooth and thick. Add the vanilla and mix to combine.

Use the buttercream immediately, or cover and refrigerate until needed. Store in a zippered plastic bag for up to 1 week in the refrigerator and up to 2 months in the freezer. (To thaw, leave in the refrigerator over-night, not on the countertop).  To use the buttercream that has been chilled, remove from the refrigerator and bring to room temperature, about 1 hour, or microwave in 15-second intervals, mixing in between each, until soft. If frosting has been frozen, this can take up to 2 minutes total. You can also soften the buttercream over a bain-marie or a double boiler. The frosting will soften from the outer edges of the bowl so mix from outside, folding the frosting inside. Transfer to a stand mixer fitted with the paddle attachment and beat until soft and spreadable, 2 to 3 minutes.

Lemon Buttercream

Scant 1 cup (225 g) heavy cream

2 egg yolks 

2 gelatin sheets

1/3 cup (65g) superfine granulated sugar

1 lemon

Lemon zest of 1 lemon

1 cup (250 g) Buttercream

Make the Lemon Custard: Soak the gelatin in cold water for 20 minutes. In a saucepan, bring the cream to a boil. In a bowl, whisk the egg yolks with the sugar. Pour the boiling cream over the egg-sugar mixture, beating hard. Pour the custard back into the saucepan and cook, stirring, just until it reaches a temperature of 185°F (85°C). Remove from the heat. Drain and squeeze the gelatin of excess water and incorporate it into the custard. Add the lemon and lemon zest, blend with a handheld immersion blender and set aside to cool.

In a bowl, blend the custard with buttercream with a handheld immersion blender to get a smooth cream.Transfer the mixture to a piping bag fitted with a star tip.

Blueberry Buttercream

1/2 cup fresh blueberries

1 Tb sugar

1 tsp lemon juice

1/2 cup water

Make the Blueberry Jam: Bring all ingredients to a boil in a saucepan over moderate heat, stirring occasionally. Reduce heat and simmer, uncovered, stirring occasionally, until slightly thickened, about 20 minutes (jam will continue to thicken as it cools).

Force jam through a fine-mesh sieve into a bowl, discarding skins. Let it cool.

Add blueberry jam to 1 cup buttercream until color desired. Blend buttercream with a handheld immersion blender to get a smooth cream. Transfer the mixture to a piping bag fitted with a Wilton tip 104.