Some thoughts inside and COML for Italian Meringue Buttercream recipe
Bo Friberg’s Italian buttercream, in his book The Professional Pastry Chef, has always been reliable for me as is the Italian Buttercream on Martha Stewart’s website (tried it when my books were packed in storage and it worked just as well). I’ve tried many over the years but those I know are tried & true. Italian has always proven to be smoother, and more stable, for me. In addition, a little shortening added will help stabilize butter, as would meringue powder (it also provides a bit of crispness). The inevitable food safety concerns come up though, since butter will melt at temperatures in the low 80F range, while shortening will hold to 100F or higher (spoilage can ruin the wedding and the honeymoon). You don’t mention the size of the cake, or number of layers, so if it’s a large one... I’d make it, frost it, and cut the larger layers in half. Transport everything in multiple coolers, reassemble, and finish decorating everything on site. If you create a 4-side design, the decorations covering the two seams will look deliberate, and if you have all your materials ready-to-apply (buttercream in a bag, offset spatula handy, flowers or petals trimmed and ready to apply) than even for a 3 or 4 tier cake it doesn’t take more than 30 minutes to finish. After cutting, the leftover cake can be stored in the coolers, available for second helpings if guests wish.
You could also freeze the cake layers (if you choose the right type of filling), before frosting/decorating, and let it thaw at the event, but the timing is tricky... so I Never use this method because I’m always worried Grandma’s gonna lose her dentures!
Good luck,
R.
http://www.marthastewart.com/page.jhtml?type=content&id=recipe1980&contentGroup=MSL&site=living
