I tried SMBC cream cheese icing but it appeared curdled. i have made lots of smbc but without the cream cheese successfully. what could have gone wrong. i used the following recipe;

3/4 cup egg whites (about 5 large eggs)
1-1/4 cups (300 g.) granulated sugar
1-1/2 lb. (454 g.) salted butter, softened
1 tsp. vanilla
8 oz. (250 g.) cream cheese, softened

Whisk whites and sugar together with a hand whisk and heat, whisking continuosly, over the top of a double boiler until the mixture is HOT, about 130 degrees.

Remove bowl and beat egg mixture on MEDIUM speed until cooled down, about 5 minutes, or until the eggs are forming stiff peaks and the mixture and bowl are cool to the touch.

On LOW speed, add butter in 10-12 additions until smooth and blended and mixture is light and fluffy.

Increase speed to HIGH and continue beating for another 5 minutes; the volume will double. When completed, add the vanilla or any other flavourings and just blend to incorporate.

Add softened cream cheese and blend on LOW until incorporated, about 3 minutes.

Note: Adding 1 Tbsp. almond extract at the end to the cream cheese frosting will accentuate the tang of the cheese.

I've never made it with cr/ch. When I do make a regular batch(without cr/ch), I beat the egg/sugar mixture until stiff then begin adding the butter. I also use (going by the quantity of egg whites you have...) about 1/4 cup more sugar and about 3/4 cup less butter...and mine takes more than 5 minutes to cool down whipping it on high.

I could only suggest that you chill it a bit and see if that helps.

I tried making SMBC w/ cream cheese and mine turned into soup!