In a clean mixing bowl add mering or egg white powder with the 10 TABL of water...add salt and cream of tartar if using...start whisking.. About 2 min later add 1/4 cup sugar SLOWLY. Once all sugar is in turn mixer to high and start whisking for about 5 min.
Simultaneously...Place sugar & water in a casserole and bring it to the boil and start the timer. Boil it on medium/low temperature. If the syrup starts to darken quickly turn down the temperature a little, bring to a boil. Once you reach a temp of 245F syrup is ready.
With the mixer still going on high speed slowly pour the hot syrup down the side of the mixing bowl. Be very careful not to get burned on the hot syrup.
When all sugar syrup has been added it should look thick and fluffy. Stop the mixer and change for the paddle attachment. To avoid meringue splatter all over your kitchen place a clean kitchen towel over the mixer. Set the timer on 10 mins and beat on high speed. This is how long it takes in my mixer for the mixing bowl to be cool to the touch.
After 15 mins. You should now have a lovely thick meringue...
Now its time to add the butter. Start the mixer on high speed and with a knife cut pieces of the butter and add it to the meringue. When all butter is added it will not take long for mixture to turn into nice thick smoothe buttercream. When that happend slow down the mixer and add 1 tsp of vanilla extract. Stop the mixer and scrape down the bowl and start again. I do this two times. You should now have a bowl full of lovely Italian meringue buttercream.
Note: If the IMBC wont combine just continue to whip whip whip. It will eventually get smooth. If you are still having problems, place both bowl with paddle attachment into the refrigerator and let it “cool” down a bit and then whip it again.
You can easily freeze any left over IMBC. Just remember to let the cold IMBC come back to room temperature before you placing it in the mixer to get it smooth.
Raspberry: 1/4 cup of raspberry puré or more pr. 2 cups of IMBC
Lemon Curd: 1/2 cup of Lemon Curd pr. 2 cups of IMBC
Chocolate: 2-3 oz of melted chocolate, cooled down to 98 F, pr. 1 cup of IMBC
Coffee: 2 tbsp of instant coffee mixed with 2 tbsp of warm (not boiling) water pr 3 cups of IMBC