i have been using a chocolate buttercream recipe that i found online - while it tastes delicious i have found that it is horrible for decorating. once it is out of the fridge it turns back to a gooey mess in no time. is there anything i can add to it to make it crust over or do i need to dump the recipe?

here are the ingredients -
12 ounces semisweet chocolate
3/4 cup egg whites (4 to 5 extra-large eggs), at room temperature
1 1/2 cups granulated sugar
1/4 teaspoon cream of tartar
3/4 teaspoon kosher salt
1 1/2 pounds unsalted butter, at room temperature
3 teaspoons pure vanilla extract
3 teaspoons instant espresso powder, dissolved in 1 1/2 teaspoons water

Do you cook your sugar to a soft ball stage...before adding to beaten egg whites?

no, the recipe just calls for warming the egg whites and sugar until they are warm to the touch. what is "soft ball stage"?

This recipe looks like "Swiss Meringue".. this is where you place the egg whites & sugar in a mixer bowl, place them over boiling water and whisk till the "sand sound" is gone. Then you place the bowl on your machine & beat till stiff ( be sure not to make it look like cottage cheese). This process should cool the mixture (touch the outside bottom of your bowl for temp checks)... then add your butter one small chunk at a time whipping in between & then the chocolate mixture (double boiler your chocolate & some of the sugar till melted add the vanila & the coffeee mix). I like to cover this icing & let sit in the fridge overnight, this allows the air bubbles to settle down... then re whip in the morning.)
Have Lots of Cake Fun!