Italian or Swiss or French?
Italian Meringues
Italian meringues are made with a sugar syrup. Sugar and water are boiled to the soft-ball stage (240 degrees F/115 degrees C) and carefully poured in a thin stream into a mixer bowl of whipped egg whites. The mixture is whipped until cool. Because of the constant whipping, the bowl cools quickly, and the egg whites may not reach pasteurization temperature; you can use an instant read thermometer to check the meringue's temperature after the first minute or so of whipping. Individuals with compromised immune systems should take care not to consume undercooked egg whites.
Swiss Meringues
Swiss meringues are made by combining sugar and egg whites and heating them over a double boiler.
- To prepare a Swiss meringue, whisk the sugar and egg whites enough to break up the whites, but not so vigorously that they form an airy foam.
- The sugar will melt and act as a protective shield against coagulation of the egg whites; heat and whisk constantly until the temperature of the whites reaches 145 degrees F or hotter.
- Remove the bowl from the heat, and beat the warm egg whites until they form stiff, glossy peaks.
Italian meringue tastes like a fluffy marshmallow to me. I find regular buttercream too sweet but italian meringue buttercream doesn't have much substance. It's sweeter than most whipped cream that I make and I prefer whipped cream frosting (just a personal thing). I wouldn't use it to pipe and decorate. This might be helpful as comparisons:
You can use IMBC to pipe and decorate, but it's fussier than an american buttercream (particularly if you're used to working with the crisco version). Italian Buttercream tastes like a stick of lightly sweetened butter when it's cold (blech). Remember the Food Network wedding cake special? Mrs. Italian cook herself Giada DeLaurentiis thought the Italian buttercream made by one of the bakers tasted "just like a stick of butter." But, consider Italian buttercream when it's warmed up and softer... then it's divine. Just don't let it get *too* warm or the piping won't hold.
More details:
The Differences–In Detail
American buttercream: This is the most basic type and usually involves creaming a fat and powdered sugared until light and fluffy. Small amounts of liquids are usually added, such as milk and extracts. This is the only type of buttercream that does not need refrigeration, due to its high fat and sugar content. It only needs to be refrigerated in warmer conditions or else it will melt.
Swiss buttercream (also called a “meringue” buttercream): This involves heating egg whites and sugar (sometimes with an acid, like cream of tartar) over a bain-marie while whisking constantly until the mixture reaches 160º F. It is then removed from the heat and transferred to a mixer, where it’s whipped to medium peaks. Softened butter is added to the meringue while whipping. Flavorings are added at the end of the process. This type of buttercream should be refrigerated if it is not being used or eaten within a couple of hours.
Italian buttercream: This is similar to Swiss buttercream, except that the egg whites are not cooked. Rather, a sugar syrup is made until it has reached soft-ball stage (240ºF) and the egg whites are whipped to medium peaks in a mixer. The sugar syrup is then slowly added into the beaten egg whites with the mixer running. Once the meringue has cooled down, softened butter is added and the mixture is whipped until smooth, fluffy, and glossy. Any flavorings are added after the addition of butter. Storage is same as Swiss buttercream.
French buttercream: This is one of the favorite buttercreams of all time. It is made exactly like Italian buttercream, except it uses whole eggs instead of only egg whites. This results in a richer, creamier buttercream and if you don’t color the buttercream, it will be more yellowish in color. This is the least stable of buttercreams and should always be refrigerated if not being used right away.
These seem to be the major four buttercreams being made out there, but I’ve learned of several others while finding information. There is decorator’s buttercream (used for making decorations such as flowers), fondant buttercream (combination of equal parts fondant and butter and used the same as rolled fondant), mousseline or neoclassic buttercream, and German buttercream (a combination of pastry cream and butter).