I use Italian meringue buttercream which comes out the same consistency and taste as Swiss. But, the sugar is cooked in a syrup to 242 degrees F. The egg whites are beaten separately in the mixer bowl to soft peaks and when the syrup reaches the right temperature it is poured slowly into the beaten egg whites on low speed, then beaten on high speed until the outside of the bowl feels cool to the touch of your palms before adding the butter and flavorings. I may be wrong here but I believe cooking the syrup to that temp. and adding it to the beaten egg whites may kill any bacteria.
Shirley
