I have been quite happy with Rose Levy Beranbaum's recipes. Adapted MOUSSELINE BUTTERCREAM
MOUSSELINE BUTTERCREAM adapted from Rose Levy Beranbaum by Sarah Phillips
Makes 4 1/2 cups - enough to fill and frost 2 9-inch x 1 1/2 layers or 3 9 x 1-inch layers
This buttercream may seem tricky to make, but once made holds up better than any other European type buttercream; it is quite stable in 75 degree F weather. "Its light and smooth and incredibly easy to work with. It is soft enough for beautiful shell borders yet strong enough to pipe roses" and can be tinted and flavored. It's like "Butter whipped into a fondant".
The recipe starts out thin and lumpy looking and about three-fourths of the way through, it starts to come together or emulsify and turn into a luxurious cream.
The temperature of the butter is important - use butter that is 65 degrees F. If it is too soft or the room too hot, the buttercream turns thin or into a grainy, hopeless puddle. If the mixture does not feel cool, refrigerate it until it reaches 65 to 70 degrees F. If the butter is too cold, then suspend the bowl over a pan of simmering water and heat very briefly, stirring vigorously when the mixture just starts to melt slightly at the edges. Dip the bottom of the bowl in a larger bowl of ice water for a few seconds to cool it. remove and beat by hand until smooth.
INGREDIENTS
1 pound unsalted butter (65 degrees F - softened but cool - not runny, greasy or soupy)
1 cup (200 grams) sugar
1/4 cup (60 grams) water
5 large (150 grams) egg whites, room temperature
1/2 + 1/8 teaspoon cream of tartar
1 teaspoon liquor of choice or optional flavorings below
A stand mixer works best, using the whip attachment for the eggs and switching to the paddle when you start adding the butter (to reduce unwanted air bubbles when icing the cake), and you'll need a candy thermometer.
INSTRUCTIONS
In a mixing bowl beat the butter until smooth and creamy and set aside in a cool place.
Have ready a 2-cup heatproof large glass measuring cup near the stove. LIGHTLY spray the inside with nonstick vegetable oil spray.
In a small heavy saucepan, under medium-high, boil 3/4 cup sugar and the 1/4 cup water, stirring constantly, until the sugar dissolves and the mixture is bubbling. Stop stirring and reduce the heat to low. (If using an electric range remove from the heat.)
With a stand mixer, using another mixing bowl and fitted with a WHISK attachment, beat the egg whites until foamy, add the cream of tartar, and beat until soft peaks form when the beater is raised. Gradually beat in the remaining 1/4 cup sugar until stiff peaks form when the beater is raised slowly. Simply turn off the mixer.
Increase the heat and boil the syrup until you get bubbles all over the surface, the syrup starts to look thicker and the Candy Thermometer registers 248°F to 250°F (the firm ball stage). Immediately transfer the syrup to the glass measure to stop the cooking. Do not scrape the bottom of the saucepan to get the last remains of the syrup.
Fit the mixer with a PADDLE attachment (not a whisk attachment.) Turn on the mixer, holding the stiff egg whites, to high. Start drizzling the sugar syrup, in a thin stream, into the contents of the bowl directly from the glass measuring cup. Aim for the space between the side of the bowl and the moving beater attachment. Do not hit the beater; the syrup will get caught in the beater and/or spin onto the sides of the bowl where they will harden, and will not get mixed into the egg whites, ruining the recipe with pieces of hardened sugar in your meringue.
Continue with the remaining syrup, gradually pouring it into the beaten meringue. For the last addition, use a rubber scraper to remove the syrup clinging to the glass measure. Lower speed to medium-high and continue beating up to 2-3 minutes to start to cool the mixture. (Feel the side of the bowl. It will feel really warm. You want to cool the mixture down before you add the butter. If not completely cool, continue beating on medium speed - no lower. Keep feeling the side of the bowl to help you gauge the temperature of the mixture. Keep beating until the mixture cools completely, taking about 5 to 10 minutes. At this stage, you have made Italian meringue. It should be glossy and thick, and very stiff. If not, start over.
Beat in the butter at medium speed 1 tablespoon at a time. After the first few tablespoons have been added, the mixture will seem thinner, but keep adding in butter slowly and beating because the meringue will thicken beautifully by the time all the butter is added. If at any time the mixture looks slightly curdled beause the butter is too cold, increase the speed slightly and beat until smooth, and then lower the mixer speed before continuing to add more butter.
Sarah Says: Italian Meringue Buttercreams are an emulsion between fat and water. When you add butter to the mixture, the temperature of the butter and whipped egg whites need to be pretty close. If the butter is colder than the egg white mixture, the beaten egg whites will curdle. If the egg whites are too hot, the butter will melt, thinning the mixture. Either place the mixture in the fridge to cool it down or warm up the egg whites by increasing the beating speed.
Lower the speed slightly and drizzle in the liquor. Don't use more than 1 teaspoon or the recipe's emulsion will break. Place in an airtight bowl. Rebeat lightly from time to time to maintain silky texture. Refrigerating the mixture to firm the fat in the butter and then rebeating helps to fluff it up, too. Buttercream becomes spongy on standing.
Will keep 10 days refrigerated, 8 months frozen. Allow to come to room temperature completely before rebeating to restore texture or it will break down irretrievably.
Variations after making the main recipe, you can beat in:
Chocolate: Beat in 5 ounces of melted and cooled bittersweet chocolate
White Chocolate: Beat in 6 ounces of melted and cooled white chocolate
Fruit: Beat in up to 3/4 cup lightly sweetened fruit puree (strawberry or raspberry) or orange, passion, lemon or lime curd.
Nutella (by S Phillips): Beat in 5 ounces of room temperature Nutella
Adapted from The Cake Bible by Rose Levy Beranbaum
Happy Baking911, Sarah Phillips, Founder and President, baking911.com - And, Housewife in the Suburbs....
Buy my cookbook, Baking 9-1-1, Simon & Schuster, 2003 ~ Read my blog (Yawn!)
http://www.baking911.com/asksarahbb/index.php?showtopic=913