Mojito Cupcakes - Part 2: Lime Italian Meringue Buttercream

The light and silky Italian Mergingue Buttercream is a stark contrast to the mainstream buttercream recipes that are rich and heavy. It is commonly used in Wedding cakes, and preferred by many professional bakers. It is the most stable and resilient to heat, compared to the other buttercream varieties.  Finally, it tastes so delicious, that you'll never want to make another frosting with powdered sugar!

Warren Brown from Cakelove has a fabulous instructional video about making the Italian meringue butter cream.  He is very good at articulating the important points.  I still managed to mess up five batches before making it correctly, and decided to include a Tips section to share my findings.  His advice is succinct, yet profound - "Do not overwhelm, do not underwhelm.  Take your time."  I couldn't agree more, and the final product is worth the precision.  If you have not made this type of frosting before, please watch the video.

TIPS

1. Do not use pasteurized egg whites, as they will not whip to the firm peak stage. 
1. Alternatives
1. Meringue/egg white powder
2. Pasteurized eggs (in the shell)
2. Anything that touches the egg whites must be extremely clean, and free of any residue.
3. Use a copper bowl.  If you do not have one:
1. Add the cream of tartar to the raw egg whites
4. Please check out Baking911's tips on making meringues and Italian meringue butter cream frosting.
1. This lady knows what she is talking about, and has a lot of tips regarding fixing mistakes

INGREDIENTS
Meringue
5 room-temperature egg whites
pinch salt
1/2 tsp cream of tartar (if not using a copper bowl)
2 ounces (1/4 cup) castor sugar

Syrup
8 ounces (1 cup) castor sugar
1/4 cup water

Butter, 1 lb., unsalted, and soft

Lime
1-2 tsp Lime oil or 
1/2 cup Lime curd  (recipe to follow)

DIRECTIONS

1. In a sauce pan, combine 8 oz of sugar and 1/4 cup water
1. Wisk and put on medium heat with a thermometer to monitor the temperature
2. Remove from the heat when thermometer reads 240 (sea level)
1. If sugar syrup approaches 230 prior to the egg white mixture's completion, turn off the heat and cover the sauce pan
2. Warm syrup up to 240 when egg white mixture is ready for the syrup
2. In a large mixing bowl, add egg whites and cream of tartar (if needed) and begin with a wire whisk attachment on medium/medium-low speed
1. Stage 1: Raw

2. Stage 2: Foamy

1. 
   
3. Stage 3 - Soft Peak: Increase mixer speed to Medium High

1. The peaks droop slightly
4. Stage 4 - Hard Peaks: Increase mixer speed to High

1. Mixture is smooth, moist and shinny.  If the beaters are stopped and lifted, straight peaks should form.
5. Begin to add extra 1/4 cup sugar slowly as mixture transitions from Hard Peaks to Firm Peaks
6. Stage 5 - Firm Peaks: Mixer is on highest speed

1. Egg whites are think, volumnious and glossy
3. When egg whites have reached the stiff peak state, change focus to the sugar syrup.
1. Syrup
1. The syrup needs to reach the 240-245 degree mark
2. If the syrup was removed from heat
1. Turn on medium to medium-high heat
2. Monitor syrup, and remove from heat as temperature reaches 240-245 degrees F
2. Add the sugar syrup to egg whites very slowly, aiming for the area between the beater and the side of the bowl
1. Watch above video for technique
2. Bowl should be warm 
3. Beat for 7 - 10 minutes
1. Outside of bowl should be room temperature
4. Slowly add the butter
1. Add 1-2 tablespoons at a time
2. Continue beating on high speed
5. Slowly add lime oil or curd
1. Taste and watch consistency
2. I haven't gotten this far in the recipe yet...

LINKAGE
http://www.cakejournal.com/archives/how-to-make-italian-meringue-butter-cream
http://www.joepastry.com/category/pastry-components/buttercream/italian-meringue-buttercream/
http://www.baking911.com/howto/egg_whites_beat.htm
http://www.cakelove.com/podcast_italianmrng.php