HELP! Merengue turns to soup after adding butter!

Might the butter have been too cool? That has happened to me before with SMBC. The butter was too cool so the whole thing deflated to look like soup with little butter flakes. When that happens, warming the bowl slightly with a hot towel, or on a double boiler, until the edges look melt-y and then re-whipping the daylights out of it has worked.

6 sticks of butter seems like way too much. Is that a miss print?

Hi Kellye! It is actually normal for the meringue to deflate - even look soupy when you first add the butter. The key is to keep whipping it - it might even look broken at one point, but it will come back together with more and more whipping. First of all - are you adding the butter gradually? Adding it only about 1-2 tablespoons at a time can help to lessen the deflating so much so quickly. And of course, it's likely to turn soupy if the butter melts when it hits the meringue - make sure the mixing bowl feels cool to the touch, not just the meringue base, which is aerated and can be difficult to tell if it's fully cool!