I've made a few true buttercreams with eggs and found the egg white only is the best tasting in my opinion.

I have now bought the egg whites that come in a carton that are pasteurized, so do you think I still need to "cook" the egg mixture over the stove top or can I skip that step? I was assuming the idea of raising the temp of the egg whites was to kill any bacteria,... or is there another reason?

maybe too late, but I'm pretty sure that pasturized eggs are for use in recipies where they won't be fully cooked, so you should be fine.

I know this was an old post, but I have the answer for anyone making Swiss or Italian Buttercream. Heating the eggs and sugar is not to kill bacteria, it is to fully melt and incorperate the sugar. If you do not, you will have gritty buttercream from the bits of sugar not melted. You do not heat the egg whites to a high enough temperature to kill any bacteria.

I also think that making Swiss Buttercream is easier than Italian. And if you never have--you must make a batch. It is a heavenly taste. However, it does need some care and must be refirgerated, even the leftovers. It can be brought to room temp to serve.

Hope this helps the Meringue Buttercream makers...

the pasteurized whites that come in a carton are ok to use without cooking.