I've submitted this recipe to be included in CC's archives twice but it's not getting greenlight by the mods for whatever reason.
I commented on another thread about SMBC about my cream cheese version and said to PM me for the recipe. Little did I know my inbox would explode today! So, I'm making a thread here to direct people.
I came up with this method (the cream cheese part, I don't actually know when I finalized my egg/sugar ratio or where I got it from). Anyway, I make this all the time.
My ratios for SMBC:
6.25 oz egg whites
7 oz sugar
pinch of salt
1 lb of unsalted fine quality butter, 72 degrees or warmer
Whisk egg whites, salt and sugar in a mixing bowl over a pot of boiling water until internal temperature reaches 160 degrees and sugar is dissolved. Remove from heat, pop onto KA mixer with whisk attachment, and beat on high until stiff peaks form and bowl is cool to the touch. This may take 10 minutes or more.
TIP: You have to get STIFF PEAKS, sometimes I'll even let my meringue (gasp!) deflate a bit. It IS possible to have a cool bowl and medium peaks. DON'T STOP! Keep mixing.
Swap out to a paddle attachment and add your room temperature butter. Mix on LOW. Yes, LOW. Not medium low, not #2, but the lowest setting your mixer has. "But wait!", you might say, "I've been mixing for 3 whole minutes and it looks weird!" Yes my friend, that is exactly what it's supposed to look like. This is science happening, so this step can take up to 15 minutes before the emulsion between the butter/sugar/eggs takes place. You can't rush it. If you crank your mixer up on high because you are impatient, it will come together but all you did was break your meringue and end up with sweetened butter (the primary complaint from people that claim to not like SMBC). When made properly, you should get about 5 cups of SMBC. BUT, I have measured SMBC that I made as fast as possible vs. SMBC that I made properly. Not only did they taste different, but the hurried SMBC has a full cup less in volume.
TIP: If you can pick your pieces of butter up with your fingers and it's still firm-ish, it's still too cold and will take much longer to emulsify. So for perfect results make sure that butter was pulled out the night before and is nice and soft.
"But wait!", you say, "I forgot to pull it out the night before!" Try grating your cold butter with a cheese grater to maximize surface area to warm it up. Then let it sit for as long as possible before use.
I DO NOT refrigerate my SMBC. Science is at work here, called osmosis. The science that works for crusting icings made with shortening, butter, cream and milk that people don't hesitate to leave out for days on end is the same science that makes European buttercreams perfectly safe.
I included the above because I don't know if my cream cheese to SMBC ratios will work with other recipes, although you are welcome to try and post your results here.
Now, for the moment you have ALL been waiting for.............
Cream Cheese SMBC (heretofor CCSMBC)
10 oz. finished SMBC
8 oz. (1 package) Cream Cheese (can be cold)
Put your cream cheese in a bowl and whip it on HIGH to make it smooth and creamy. Pass thru it with a spatula just to make sure there are no pesky lumps. Keep whipping. Once it's nice and smooth, add your finished SMBC in batches, mixing on high (1/2 or you can do 1/3 if you are making a bunch). This is where people have gone wrong in the past. Notice I said add the SMBC to the cream cheese, NOT the other way around. Very important. Until you have made this a few times, you will need to watch it because if you add too much SMBC it will start looking glossy and curdled. If this happens, add more cream cheese (but make sure you follow the "whip it until it's smooth" step, if you toss in a lump of unwhipped cream cheese in it will never break down and emulsify.)
Finished CCSMBC is softer then regular but is great for topping cupcakes or using as a filling (damed with regular SMBC). I do not put it on the outside of cakes or under fondant (except as a filling) because of the softness, I worry about my layers shifting. It also has a very strong cream cheese flavor (which is hard to get using any other icing) so personally I think covering a whole cake is overkill.
Refrigeration: I have had iced cupcakes and cake out for 12 hours with no problems, flavor or texture changes. More then that though and it gets a strange... film? Almost like the film you get on custard or curds that do not have direct contact with plastic wrap when it's left out for longer with direct air contact. So in this rare instance I do refrigerate if I use it in advance or if it's in a cake just to protect the flavor and prevent that strange film from forming.