Grapefruit Chiffon Cupcakes

Last weekend, David and I went to his sister's house for one of our nephew's birthday party.  When the party was over, several of us went grapefruit picking.  David's sister lives next to a grove of grapefruit trees that we assume doesn't belong to anyone because the ground is overgrown with thorny bushes and there are several overripe grapefruits decomposing under each tree.  At any rate, we picked to our collective hearts' content.  I picked one of each of the three varieties of grapefruit, but my father-in-law went a bit overboard and gave half of his loot to me, despite my protests that I'm the only one in the apartment who eats grapefruit and that the fruit will go bad when we leave to visit my family in a week.  He insisted that they would keep, and this is how I ended up with a plastic bag so full of grapefruit that it's bursting at the seams.

A freakishly large grapefruit

I could probably be happy eating them broiled every morning, but I decided that I wanted to experiment with the grapefruit.  Grapefruit is a fruit that doesn't show up very often in baked treats, probably because of its slightly bitter taste or because its zest isn't as pungent as that of lemons and oranges.  I briefly considered recreating the Hollywood grapefruit cake, but layer cakes can be time consuming and aren't as easy to share (and boy, did I want to share - I've eaten way too much cake this week).  After some consideration, I decided to do a variation of my family's favorite treat: chiffon cake.

Chiffon cakes are a lot lighter than their butter-based counterparts, but not quite as airy as angel food cake.  I was a bit worried that they wouldn't turn out well, as I usually have a lot of trouble beating egg whites to stiff peaks.  I've read so many tutorials that I should be able to do it with my eyes closed, but I guess that baking, as with most things, requires not only knowledge of theory, but lots and lots of practice.  I can usually get the egg whites to stiff peaks, but then they separate for some reason.  The top of the bowl would be foamy, but there would be liquid underneath.  I'm still not sure why this happens - perhaps I've been overbeating them?  At any rate, this is the first time I've beaten cream of tartar and sugar into the egg whites, and it really made a difference - the egg whites didn't separate this time!  Yay! 

I loved these cupcakes.  They're light and airy, and not too sweet.  The grapefruit flavor came through in the cupcakes, but it was really mild and subdued.  David really liked the cupcakes a lot, and he doesn't even like grapefruit!  We tried eating them with several different toppings.  My favorite way to eat them was after dipping the top into granulated sugar.  I really liked the crunch of biting into them and the little bit of extra sweetness it provided.  I also liked them sprinkled with a little bit of powdered sugar.  I tried piping some white chocolate cream cheese icing (leftover from the stuffed strawberries) onto the cupcakes, and while I thought that it slightly overpowered the cupcakes' flavor, my coworkers liked the frosted cupcakes best.

Grapefruit Chiffon Cupcakes
Makes about 40 cupcakes

2 1/2 cup cake flour
1 1/2 cup sugar + 3 tablespoons, divided
1 tablespoon baking powder
1/2 teaspoon salt
1/2 cup vegetable oil
8 eggs, room temperature
3/4 cup fresh grapefruit juice
2 tablespoons grapefruit zest
1/2 teaspoon cream of tartar

Preheat oven to 325 degrees.  Line muffin tins with cupcake liners.

Separate the eggs into whites and yolks.  Set the whites aside in a large, clean bowl. 

In another large bown, whisk egg yolks with 3/4 cup + 3 tablespoons sugar, until pale yellow and smooth.  Whisk in oil, juice, and zest until combined.  Sift in flour, baking powder, and salt; stir until throughly combined.  The batter should be thick, and fall in thick ribbons.

Using an electric mixer, beat the eggs until foamy.  Add the cream of tartar, and beat until soft peaks form.  Slowly add the remaining sugar, little at a time, until stiff glossy peaks form.

Stir in 1/4 of the egg white mixture to the grapefruit batter, to lighten it up.  Fold in the remaining egg whites gently until no streaks remain.  The batter should be light and foamy.

Divide batter between muffin tins, filling each one almost to the top.  Bake for 20-25 minutes.