Ok, I think maybe I fear SMBC, but I love it. Let me first say, that I cook egg/sugar to 160 then mix with whip until bowl is room temp - maybe sometimes still just a bit warm, but eggs are now stiff peak.

Switch to paddle, incorporate butter. When all incorporated, turn on high until I hear the "thwapping" which tells me it's thick enough.

NOW - here's the kicker. My mixer has a monster motor, and if I let it go 30 seconds past thwapping the SMBC starts to break down losing TONS of volume. Recipes that say I should have close to 7 or 8 cups, and I only have enough to tort a 10" square and crumb coat! Not even enough to frost (which is fine, I cover all in fondant).

HELP? Anyone? Do I need to mix longer, or stop sooner? I'm not mixing even half the time of these 6-10 minute recommendations. (Again, big motor mixer)

Thanks in advance!
-Teri

I would say mix longer. Any fat will deflate meringue, but if you beat longer, the SMBC should come together. Hopefully others will chime in with their guesses too.

I mix mine way longer than 6-7 minutes. I always make a double batch because one usually isn't quite enough.

Ok... one/two more things. Are you mixing on high? med/high, low? My mixer (Waring) had 12 speeds, I keep it around 6.

Also as a note, my ratios are 1 part eggs, 2 parts sugar, 2 parts butter.

I start off slow during my additions then increase to medium...once it starts to fluff back up, sometimes I'll increase the speed for the last few minutes. During the winter, it was very cold in my home, and I found that I had to mix my SMBC for 20 minutes before it started to look like frosting.

Here's my recipe for SMBC Never fails.
486 grams egg whites
800 grams sugar
Heat over simmering water to 140 deg. F
Use whip attachment to whip meringue to firm peaks
Change to paddle attachment.
Add 1200 grams semi-soft butter: bury 1/4 of it in meringue, start mixer on low and add rest gradually. Scrape down after all butter incorporated. Add teaspoon of salt and 2 oz. extract, liquor, etc. Whip BC at med-high (6 on a 6 qt. Kitchenade mixer) for about 2 or 3 minutes. It doesn't take long. It makes LOTS, tastes great and holds up great.
Sharie

I ALWAYS heat the egg whites to 160 degrees and I always cut my butter into tablespoon size pieces and add them straight from the fridge. Too soft butter will affect your icing. I use the Well Dressed Cake SMBC found on this site. It turns out perfect everytime. I do double the receipe though because one batch is never quite enough. I usually add 2/3 cup (to a double receipe, 1/3 cup for regular) of melted white chocolate and about 1/3 cup raspberry puree. It's so good you can eat it straight from the bowl. I start beating the egg white mixture at about 6 ( or a little higher) on my mixer and after it forms stiff peaks I start adding the butter. Once the butter is fully incorporated I turn it down a notch or two and continue to beat for several minutes (sometimes 20-30). When it's completely done I add the melted (cooled but still pourable) white chocolate and raspberry puree. I mix until it's all incorporated. Yummy

I can appreciate that you feel your recipe is the correct one but every cake decorating book I have (Kerry Vincent, Colette Peter, etc.) instructs to cook the egg whites to 140 deg. I take their word for it, thanks.

I actually talked to a the university where they conduct food testing for safety and they generate nutritional labels. 140 is where egg whites alone need to cook to. You can actually get away with 140 and not 160 because of the sugar content being so high, it makes the eggs safe (non-potentially hazardous). You're good either way. That said... I still go to 160

UPDATE: I beat the dickens out of the SMBC last night with a timer on to make sure I really truly did it for at least 10 minutes - it's heavenly!!! I was just too scared to keep mixing once I hit that 3 minute curdle.