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Bright blue frosting made with blue spirulina.

Blue Vanilla Buttercream

Vanilla buttercream that holds a piping shape and takes the blue evenly.

Frosting and pastry

Blue Vanilla Buttercream

This is a basic American buttercream: butter, icing sugar, vanilla and enough milk to loosen it. Whipping the butter first makes a noticeable difference to the final blue.

What you'll need

  • 250 g unsalted butter, softened
  • 350 g icing sugar, sifted
  • 2 tsp vanilla extract
  • 1/4 tsp fine salt
  • 1-2 tbsp milk or whipping cream
  • 0.5-1 g blue spirulina

The paler the butter, the bluer the frosting. Deep yellow butter will push it towards aqua.

Make it

  1. 1Beat the butter for 4-5 minutes until noticeably paler and fluffy.
  2. 2Add the icing sugar in three additions, mixing slowly at first, then beat until smooth. Add the vanilla and salt.
  3. 3Stir 0.5 g blue spirulina into 1 tablespoon milk or cream until smooth. Beat it into the buttercream until the colour is even.
  4. 4Adjust the consistency with a little more milk if needed. For a deeper blue, disperse and add the remaining blue spirulina a small amount at a time.

Get an even blue

Don't add the powder dry. Mixing it with a spoonful of milk first prevents the dark specks that are awkward to chase through a full bowl of frosting.

Give the finished buttercream five minutes, then stir it once more. The colour often looks more even after that short rest.

Try it with

Two-tone

Keep one-third of the buttercream white and load both colours side by side into the piping bag.

Vanilla-almond

Add 1/4 teaspoon almond extract with the vanilla. More than that can overpower the frosting quickly.

Lighter blue

Colour half the batch, then blend it back into white buttercream until the shade is right.

Making these for a cafe?

For repeatable production, record the colour as grams per kilogram of finished buttercream.

  • 1 kg finished white buttercream
  • 1-2 g blue spirulina
  • Enough milk or cream to make a smooth dispersion

Start with 1 g per kilogram for a soft blue and increase gradually.

Approve the colour under the same lighting used for display, then record the final dose for the next batch.

Make yours blue

PrismaBlu™ Vivid blue spirulina powder.

PrismaBlu™ Vivid

Blue spirulina powder

Choose a pack
See the blue spirulina heat guide