Although no further decoration is required post baking, piping these rainbows require some patience and dexterity. Thankfully a small quantity is requested for these so it was still manageable. I made these rainbows along with Meeples and Miffy macarons.
I filled the macarons with lemon swiss meringue butter cream (smbc) and lemon curd or salted caramel smbc with salted caramel center as requested.
I don't think I can provide the templates for these as I have templates for rainbows and clouds (separately) in my Creative baking: Macarons book. Check out the link at the end of this post for more details of the book!
Recipe for macaron shells (makes about 45 rainbows on clouds, 90 shells)
200g almond meal/flour (preferably superfine)
200g icing sugar
200g caster sugar
160g egg whites divided into two equal portions
1/8 tsp red yeast powder (optional)
1/2 tsp natural yellow powder food colouring (optional)
1/2 tsp carrot powder (optional)
1/2 tsp white powder food colouring (optional)
Gel food colouring
1. Prepare baking trays with "rainbow on clouds" template under baking paper. Stick the corners of baking paper with Italian meringue when you have made the meringue.
2. Make the mass. Sift almond and icing sugar together in a large mixing bowl. Add 80g egg whites and mix well to form a thick paste. Divide the paste into 1:1:1:1:1:5 for red:orange:yellow:green:blue:white. Add food colouring until desired shade is obtained. I prefer natural sources of colouring but they tend to be dull and insufficient when you need strong and bright colours.
3. Prepare the Italian meringue. Boil caster sugar and water in a small saucepan until 115°C. Use a candy thermometer to monitor the temperature. In the mean time, beat the rest of the egg whites in a clean metal bowl at medium low speed until soft peaks form. Do not beat past this stage. Reduce mixer speed if necessary. Once temperature of syrup is reached, remove from heat, turn up mixer speed to medium high speed and carefully pour syrup into egg whites, avoiding the beaters. Continue beating for another 10 minutes until cool, stiff and glossy. Divide the Italian meringue for the various colours using the formula weight of Italian meringue = 0.55 x weight of mass.
4. Macaronage. Fold the Italian meringue into the mass in two additions until the consistency is like slow-moving lava. The first addition is about a third of the meringue. You may refer to this post for video tutorials of the macaron basics.
5. Transfer the batter into piping bags fitted with a Wilton #5 tip for the rainbow colours and #7 tip for the clouds. Pipe the rainbows and clouds onto baking trays. Use a toothpick to nudge the batter into place where necessary. You may refer to this post for video tutorials on how to pipe complex shaped macarons. Bang the tray hard on the table top a few times to release trapped air bubbles.
Batter in piping bags! Looks pretty on its own!
6. Let the shells dry under a fan or in an air-conditioned room until no longer sticky to touch. About 1-2 hours, depending on humidity. Preheat oven to 130°C towards end of drying time. Set oven rack to second lowest position.
Piping rainbows on clouds
7. Bake for 18-22 minutes, rotating the tray halfway through baking. If the feet of the shells still appear wet, bake for another 5 minutes at 115°C. Cool completely before peeling the baking sheet away from the shells.
Freshly baked rainbows!
You may refer to this post for salted caramel recipe, this post for lemon curd recipe and this post for the basic vanilla swiss meringue buttercream (smbc). Salted caramel smbc is made by combining 80g of salted caramel for every 100g smbc. Lemon smbc is made by combining 35g of lemon curd for every 100g smbc.
Filling up the shells!
Store the filled macarons in the fridge in an airtight container for at least 24h before serving.
Pre-orders for Creative Baking: Macarons is now open from 10-21 Feb! Don't miss the dates!