Ski, what a horror story!! It’s so disappointing when things don’t turn out. I told my husband, just the other day, that I don’t mind when people don’t like the things I make when I know they taste good and that they turned out as expected. What really gets me is when I can’t get a recipe to succeed!!
Hector, back to your rules, I had a hard time getting my bowl cool to the touch, as you mention. So, you overcome that issue by cooling the butter? Are you saying that you don’t wait for the egg whites to cool completely? I went ahead and added the butter (at about 62 degrees) and it seemed to curdle. I got nervous about adding more butter and put the bowl in the fridge until it cooled off. But, if you say it’s safe to keep adding the butter, I’ll try that next time.
Hector’s “rules” are great for huge batches of buttercream because the increased sugar syrup takes substantially longer to cool than a single batch.
I’ve had very good results cooling the meringue using the water jacket attachment and ice, or holding ice packs or frozen veggies against the mixer bowl. If you’re making a standard sized recipe, the meringue will cool completely in a much shorter time (no need to force the cooling). I’ve never had any trouble using room temperature butter (65-72F), and I’ve even thrown the butter in without whipping it first when I’ve been in a hurry (haven’t noticed any difference between the finished buttercream made with/without whipped butter).