Raspberry Swiss Meringue Buttercream

Recipe by: Allie Roomberg

Serves: frosts 2-3 cake layers (10" cakes)

Prep time: 30 minutes

Cook time: 20 minutes

Ingredients:

2 cups frozen raspberries (thawed)

6 egg whites, room temperature

2 cups sugar

454 g (2 cups or 16 oz) unsalted butter, softened

This was my first ever attempt at Swiss Meringue buttercream. And I have thoughts about it. 

1) it is not as sweet as standard buttercream (huge pro!)

2) even though it has less sugar, it still keeps its structure from the eggs and butter (another big pro!)

3) it tasted almost tooooo buttery (con? add less next time and forfeit a bit of structure?)

4) if it was too runny or too thick, it was easy to fix (a pro!)

5) I was hoping for a more raspberry-like taste (con) but I was very pleased by the natural colour (pro!)

Overall, I was daunted by a frosting requiring such precision but it was a rather straightforward task that felt accomplishing because it "seemed" difficult. Let's dive in! 

Allie has a general guide for Swiss meringue buttercream. I cover the basics of her post, here. 

p.s. The cakes (above) were piped with a sandwich bag with a hole cut in the corner and a hand-cut baking paper stencil of a circle and a heart. Some days, we take small wins with simple tools. 

Ingredients:

2 cups frozen raspberries (thawed)

6 egg whites

2 cups sugar

454 g (2 cups or 16 oz) unsalted butter, softened

Directions:

1. Puree raspberries and strain the fruit through a fine mesh sieve into a small pot. Discard the seeds. 

2. Cook the fruit puree on medium low heat until it is thickened and the volume decreases by about half (cooked puree will yield about 1/4 - 1/3 cup). Set aside to cool. 

3. Meanwhile, create a double boiler by heating several inches of water in a cooking pot to a simmer. Nestle a large heatproof bowl (preferably glass) onto/into the cooking pot without the bottom of the bowl touching the water. 

4. Add the sugar and the egg whites to the heatproof bowl and whisk continuously until the sugar is dissolved and the mixture is thickened. This is achieved when the hot liquid is no longer gritty between two fingers. It will also resemble the stickiness of liquid marshmallow. 

5. Remove the bowl from the heat and begin to mix with hand or a stand mixer on medium-high speed until the sugar-egg mix is fluffy, stiff, and cooled down (10-15 minutes). Scrape the sides of the bowl as needed throughout the process. It will go from a yellow-ish colour to bright white. 

6. Continue whipping the frosting and add butter, about 14 g (1 tbsp) at a time, scraping the sides of the bowl as needed. 

6.5 If the mixture is runny, refrigerate 10-20 minutes and re-whip. If the mixture is too firm, leave at room temperature or mix and reheat over the double boiler for a few minutes until it begins to soften, then remove promptly and re-whip. 

7. Once butter has been incorporated and the mixture is fluffy and spreadable, mix in the raspberry puree. 

8. If needed, repeat step 6.5 such as when using leftover Swiss meringue that was stored in the fridge. 

9. Decorate cake by preferred method.