Serving: 6-7 slices
Ingredients: 4 egg whites (room temperature), 4 egg yolks (room temperature), 45g cake flour, 80g caster sugar, 1/2 teaspoon cream of tar tar, 6 colorings (gel type).
Add cream of tar tar into egg white, beat until it gets foamy. Add 1/4 of sugar in, continue beating until soft peak forms. Add in another 1/4 sugar and continue beating until stiff peak forms. Do not skip the cream of tar tar. This is crucial for the batter which makes it more firm and not runny, you will get the defined lines for each color.
Set aside meringue. Add remaining caster sugar into egg yolk and beat until thicken and turn pale yellow. Sift in cake flour, using a hand whisker, moisten the mixture. Mix sure no lumps. Add 1/3 of meringue into egg yolk batter, mix till combine using hand whisker. It’s ok to flatten the meringue in this step. Once combine, fold in the next 1/3 meringue into batter, using the folding method and combine well. Becareful from this step on, be sure to use folding method so that you keep as much air in the batter as possible. Continue until last 1/3 meringue is combine amd batter is smooth and glossy.
Distribute the batter evenly into 6 portions. I weigh my batter and each portion is about 57g. Add each coloring in and mix well using folding method too. I added about 3 drops/color because I wanted darker colors.
Transfer the colored batter into piping bags.
Smoothed the surface of the batter gently, tapped against table to remove trapped air bubbles and bake in pre-heated oven at 170 degrees C for 24 mins.
When done with baking, immediately remove cake from baking tin, cover cake with baking sheet. This is an important step. This ensures the cake retain moisture while cooling down. It will be easier to roll the cake afterwards. Let it cool for at least 15 mins.
Cover cake with new baking paper and removed the old one. This is the colored surface of your swiss roll.
I always beat my whipping cream on top of a bowl of ice water. It works alot better for me. Add everything together and beat till creamy and firm.
I rolled it this way in which each slice is a full color. You can choose to roll it the other way so that each slice have 6 colors. It’s up to your preference.
Wrap the cake in baking paper and cling wrap, chill in refridgerator for at least 3 hours. I chilled mine overnight.