Frosting - Mousseline - w/MHC - 2 cup

By mariannefeldman

Makes 2 cups/12 oz/337 grams
from Rose's Heavenly Cakes p 147
makes enough for (1) 6 X 3" cake sliced into 3 layers w naked sides - recipe for "Miette's Tomboy" p 145

This book changes procedure for incorporating meringue & butter -dif than The Cake Bible

See book for flavor variations:
passion p 393, strawberry p 93, "whoopie
marshmallow cream" p 375, raspberry p 149
vanilla p 147
*plain vanilla is very buttery

or see The Cake Bible for variations for 4 1/2 cup (p 245) or 11 cup (p 515) recipes:
chocolate,
white chocolate or
fruit-
note that these will change color of frosting (except for white choc) & can also be used as fillings, as shown in Dotted Swiss Dream w Lemon curd mousseline, TCB p 222

See recipe for Mex hot choc variation



Use pasteurized eggs if any issues with under cooked eggs (Eggology works, "egg beaters" types do not whip into meringue)

*Do not rebeat chilled buttercream until it has reached room temp or it may curdle

Ingredients

• unsalted butter, preferable high fat, slightly softened but cool (65 degrees:
• 13 tbs (1 1/2 sticks plus 1 tbs) = 6.5 oz = 185 grams
• 2 1/2 large egg whites (pasteurized if desired) at room temp: 1/4 cup plus 1 tbs (2.5 fl oz) = 2.6 oz = 75 grams
• sugar: 1/2 cup, divided = 3.5 oz = 100 grams
• water: 2 tbs (1 fl oz) = 1 oz = 30 grams
• cream of tartar: 1/4 plus 1/8 tsp
• vanilla extract: 1/2 tsp
• for Mexican Hot Choc variation: beat in at end:
• 1 1/4 oz dark choc-melted & cooled
• 1.5 oz white choc-melted & cooled
• 1/3 tsp cinnamon (or to taste)
• 1/6 tsp cayenne (or to taste)
• 1/3 tsp ancho chile powder (or to taste)

Preparation

Step 1

Beat the butter in stand mixer w/flat beater on med high til creamy, abt 1 min.
Set aside in cool place (no higher than 70 degrees)
-
Pour egg whites into mixer bowl.
Have ready a 1 cup or larger heatproof glass measure.
-
In small saucepan, pref non stick, stir together 1/4 cup plus 2 tbs of the sugar & the water til all sugar is moistened.
Heat on medium , stirring constantly til sugar dissolves & mixture is bubbling.
Stop stirring & reduce heat to low.
-
Beat the egg whites with whisk beater on medium til foamy.
-
With the mixer off, add cream of tartar.
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Raise speed to medium high & beat til soft peaks.
-
Gradually beat in remaining 2 tbs sugar til stiff peaks.
-
Inc heat under sugar syrup & continue to boil til instant read thermometer reads 248- 250 degrees (firm ball stage).
-
Immediately transfer syrup to glass measure to stop cooking.
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If using stand mixer, with mixer off to keep it from spinning onto sides of bowl, add syrup to egg whites.
Begin by pouring a small amt of the syrup, immediately beat on high speed for 5 seconds.
Add remaining syrup the same way in 3 parts.
For the last addition, use a silicone scraper to remove syrup clinging to glass & scrape it off against the whisk beater.
If the syrup has hardened before most of it has been poured soften it to pouring consistency for a few seconds in the microwave.
-
If using handheld mixer beat the syrup into the egg whites in a steady stream, dont allow syrup to fall on beaters or it will spin onto sides of bowl.
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Lower the speed to medium & continue beating for up to 2 mins.
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Refrigerate the meringue for 5 - 10 mins, or until temp is 70 degrees. Whisk after the first 5 mins to test & equalize the temp.
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Put bowl with butter onto mixer & use whisk (no need to wash first). Beat on medium high for abt 3 mins or til butter lightens in color & is no warmer than 70 degrees.
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With silicone spatula scrape meringue into the butter & beat on medium til smooth & creamy.
Beat for abt 2 mins, scrape sides of bowl as necessary.
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At first mixture will look curdled. If it starts watering out, check the temp-should feel cool & be no lower than 65, no higher than 70.
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If it is too warm, set the bowl in larger bowl of ice water & stir gently to chill it down before continuing to whisk
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If it is too cool, suspend the bowl over a pan of simmering water (do not let bowl touch water) & heat very briefly, stirring vigorously just starts to melt slightly at edges.
To stop the warming, dip bottom of bowl in larger bowl of ice water for a few seconds to cool.
Remove bowl from ice water & beat the mousseline by hand til smooth.
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Beat in the vanilla.
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Mousseline becomes spongy & fluffy on standing; good to eat but needs to be smooth when frosting the cake.
If you dont use it right away, whisk it lightly by hand to maintain silky textures before applying to cake.
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Do no rebeat chilled mousseline until it has reached 70 degrees , this will prevent it from breaking down.