This vegan pink champagne buttercream is airy, light, and not overly sweet. Made using just 5 ingredients, it follows the Italian meringue buttercream making method and is perfect for frosting everything from vegan champagne cupcakes to three-tier vegan champagne layer cakes.
Preparation (At least 2 hours before making the buttercream)
Start by reducing the aquafaba, add it to a saucepan and bring it to a boil. Reduce the heat and allow it to simmer until it has reduced to half a cup in volume. After 5 minutes of simmering, check the volume by pouring the liquid into a measuring cup. If there's more than half a cup of liquid continue to simmer until it reduces to the required half cup. Pour the reduced aquafaba into a jar and refrigerate. This can be done the night before or at least one hour in advance of making the recipe.
To make the pink champagne syrup add the champagne/prosecco/cava to a saucepan with 50g of sugar and the sliced strawberries and bring to a simmer. Cook on medium heat for about 10-15 minutes, until the liquid has reduced to a quarter cup in volume. Pass the mixture through a sieve to remove the strawberry pieces and chill until ready to use.
Buttercream
Remove the vegan butter from the fridge about an hour before making the buttercream, and cut it into 1” chunks.
Add 200g of the caster sugar and water to a saucepan, gently stir and allow the mixture to sit for a minute until the sugar dissolves into a paste. Place the saucepan on medium-high heat and allow the mixture to come to a simmer and bubble. DO NOT STIR throughout the entire process. Place your candy thermometer into the syrup and continue to simmer until the mixture reaches 120°C (248°F) - about 10-12 minutes.
Meanwhile, prepare the aquafaba. Take a large clean bowl, and make sure it's completely dry and free of any grease. Add the aquafaba and cream of tartar to a large bowl and whisk on high speed for 5 minutes until soft peaks form.
Slowly add in the remaining 50g of caster sugar, one dash at a time while continuing to whisk and incorporate the sugar into the aquafaba. Continue whisking for another 3 minutes.
Once the sugar syrup has reached the correct temperature begin to add it to the whipped aquafaba. Slowly drizzle in a little at a time and continue to whisk until the mixture is incorporated. Be careful not to add the syrup too quickly as this could deflate your Italian meringue. Whisk the meringue mixture for another 10-15 minutes until it has cooled to room temperature.
Start slowly adding the chunks of butter to the meringue, one at a time, allowing the mixture to incorporate for about 5 seconds between each one. The mixture will flatten as you add the butter, just continue to add the butter as it will stiffen when the full amount of butter is incorporated. Once all the butter has been added the mixture be thick like buttercream, continue to whisk on low for 5 minutes.
Add the reduced pink champagne one tablespoon at a time, whisking for about 30 seconds between each one to incorporate the liquid into the buttercream. Once all of the syrup has been incorporated continue whisking for 2 minutes.
For best results I recommend using this buttercream fresh, ice the cake as per the instructions in Anthea’s Pink Champagne Cake recipe. If you want to prep the buttercream the day before decorating your cake you can store it in the fridge in an airtight container. Let it soften slightly at room temperature for 1.5-2 hours before using.
Storage
For best results, I recommend using this buttercream fresh. If you want to prep the buttercream the day before decorating your cake you can store it in the fridge in an airtight container. Let it soften slightly at room temperature for 1.5-2 hours before using.
Notes
Aquafaba: The liquid part from tinned chickpeas.
I have trialed this meringue using both regular and reduced aquafaba, skipping this step means that the recipe will require about 100g more vegan butter in order to stabilize.