1 ½ cups plus 1 tablespoon sugar
½ cup water
½  cup egg whites
3 sticks unsalted butter; softened

¼ teaspoon fine salt
orange and yellow food coloring

candy thermometer

Tangerine syrup:
½ cup tangerine juice
½ cup Meyer lemon juice (or ¾ tangerine and ¼ lemon if you can’t find Meyers)

This will make enough buttercream for an 8-inch layer cake. Don’t double it if you’re making the small cake. I still had some leftover from the lavender macarons, so I don’t have pictures of every stage. I will add them next time I make buttercream. Sorry!

Boil tangerine and Meyer lemon juice until it’s reduced down to ¼ cup.
Mix 1 ½ cups sugar with water in a small, heavy saucepan. Add in the tangerine syrup. Cook over high heat until syrup reaches 238 degrees F on a candy thermometer (soft ball stage). Watch it closely when you’re getting to 200; it’s fast at the end.

While syrup is cooking, beat egg whites until firming up. Add 1 tablespoon sugar and beat until stiff, but not dry.

With mixer on low, stream syrup into the egg whites. (Caution here! The syrup is really hot. Make sure you don’t pour onto the whisk- splatters are bad). Continue to beat mixture until it is no longer hot. To speed this process along, I use ice packs around the bowl. It looks funny, but it cuts the waiting time almost in half. Your mixer will be running for a long time here.

Cool to room temperature and then beat in the softened butter, 1 tablespoon at a time, until all is incorporated. The mixture will become thin and may look curdled at first, but will then become smooth as it beats. Finally, add in the food coloring.

If you need to refrigerate the extras for another use, keep in mind that it will need to come all the way to room temperature before it will beat back into the buttercream texture.

The real keys to success with this recipe is precision on the sugar syrup temperature, patience in letting the meringue cool before adding butter and remember, there’s no such thing as over beating this frosting. When it’s too wet looking, cool further and beat in more butter.

Now you have your tangerine buttercream. If you just want this plain, you can ignore the tangerine syrup stage and add in vanilla at the food coloring step. Or experiment with other flavors. I do salted caramel, passion fruit, pumpkin, etc. Syrup is where the fun is!