Singapore Cooks

The science of baking

Susanne Ng shares her recipe for six-flavour rainbow hearts chiffon cake.
Susanne Ng shares her recipe for six-flavour rainbow hearts chiffon cake. ST PHOTO: TAMARA CRAIU

Former biomedical researcher Susanne Ng says both science experiments and baking require great precision

When biomedical researcher Susanne Ng hung up her laboratory coat seven years ago to become a housewife, she thought that her days of carrying out precise measurements were over.

Then she picked up baking.

Instead of handling cell tissues and chemicals, she now works with flour and eggs, whipping up whimsical chiffon cakes that have multiple layers and are adorned with fancy designs. The cakes also come in all sorts of shapes, from an airplane to a bouquet of roses.

The 36-year-old says that her baking sessions are like conducting science experiments.

"Both require a lot of precision in weighing ingredients and are very hands-on," she says. "Having a cake turn out right is as satisfying as getting positive results from an experiment."


Susanne Ng’s
 six-flavour
rainbow hearts
chiffon cake
 involves two
rounds of
 baking. -ST PHOTO:
TAMARA CRAIU

Her cutting-edge bakes include a six-flavour rainbow hearts chiffon cake.

  • INGREDIENTS

    For chiffon layer cake:

    •2 egg yolks

    •43g caster sugar

    •23g vegetable oil

    •30ml water

    •40g cake flour, sifted

    •3 egg whites

    •1/4 tsp cream of tartar

    For coloured chiffon cake segments:

    •4 egg yolks

    •27g caster sugar

    •47g vegetable oil

    •53ml water

    •80g cake flour, sifted

    •6 egg whites

    •60g caster sugar

    •1/4 tsp cream of tartar

    For the colouring:

    • Red: 6g strawberry puree, from three to five mashed strawberries mixed with 1g strawberry paste

    • Orange: 6g orange juice mixed with zest from of an orange and 1g orange paste

    • Yellow: 6g lemon juice mixed with zest from 1/3 of an lemon and 1g lemon paste

    • Green: Cut 10 to 15 pandan leaves into small pieces, blend with 50ml water, strain with a sieve to extract the liquid and discard the pulp. Mix the juice with 1g of pandan paste.

    • Blue: Soak 35 dried blue pea flowers in a small bowl with 10ml hot water for 15 to 30 minutes. Strain liquid into another bowl, squeeze flowers to extract the liquid and discard pulp. From this mixture, remove 6ml of blue pea flower extract, mix with 1g vanilla extract and a drop of Wilton blue icing colour

    • All flavoured pastes and the Wilton blue colouring can be bought from baking supplies shops such as

    Phoon Huat and Bake King.

  • METHOD

    For the plain chiffon cake:

    1. Preheat oven to 160 deg C. Line a 25cm square baking tray with baking paper.

    2. In a mixing bowl, add egg yolks and 13g caster sugar, then mix with an electric mixer on medium speed.Add vegetable oil and water and mix contents till they are a pale colour.

    3. Add cake flour into mixing bowl. Mix till all the flour is incorporated into the mixture. Set aside.

    4. To make the meringue, add egg whites and cream of tartar to a clean, grease-free mixing bowl. With an electric mixer on high speed, whisk the contents till they turn foamy. Add 15g of the caster sugar and whisk at high speed until soft peaks form.

    5. Add the remaining caster sugar and whisk at high speed until firm peaks form.

    6. With a spatula, gently fold one-third of the meringue into the batter. Repeat for the remaining two portions of meringue.

    7. Pour the batter into the baking tray. Gently tap it on a countertop to release bubbles and bake for 14 minutes. Insert a skewer into the centre of the cake. If it comes out clean, it is done.

    8. Flip over the cake from the baking tray onto a clean sheet of baking paper and cover the top with another sheet. Leave it to cool for 15 to 30 minutes.

    9. Cut the cake into 7cm by 7cm squares. Cut out six heart shapes using a cookie cutter.

    For the coloured chiffon cake:

    10. Repeat steps 1 to 3 to prepare the batter. Divide into six portions (about 6 tsp for each portion) and place in  six small bowls. Mix the colouring into each bowl.

    11. Repeat steps 4 to 6 to make the meringue. Divide it evenly among the six bowls. Mix the contents until the colour of the batter is even. Set aside.

    12. Arrange the heart-shaped cut-outs on the base of a tube pan and arrange cake squares vertically around the pan to create six segments.

    13. Scoop a different coloured batter into each segment gently but quickly. Tap the tube pan on a countertop to release any air bubbles in the batter.

    14. Bake the cake at 160 deg C for 15 minutes, then at 150 deg C for 15 minutes and finally at 140 deg C for 15 minutes. A skewer inserted into the cake should come out clean.

    15. Turn the pan upside down and place it on a wire rack and leave it to cool for 30 minutes. 16. To remove the cake from the pan, gently use your fingers to pull the cake from the sides of tube pan, turning the pan as you loosen the sides. Lift the removable base and invert the cake. Lift and remove base of the tube pan to release cake. Serve.

    Serves eight

There are two rounds of baking. The first involves making a chiffon layer that is used to partition slots between the six coloured segments of the cake. It is also cut to produce heart shapes that appear on top of the cake.

The other round is for baking the coloured sections of the cake. To do so, she separates the batter into six portions and colours them individually using ingredients such as blue pea flowers, pandan juice and pureed mashed strawberries.

She says that it is tricky to fold in the meringue quickly with the various dyes, as it has to be done repeatedly for each coloured batter and in quick succession within six minutes.

"If one's movements are too slow, the meringue breaks down fast, which leads to a rough cake texture," she says.

This cake is one of 30 recipes in her cookbook, Creative Baking: Chiffon Cakes, which was launched last month by Marshall Cavendish. The 111-page book contains recipes for multi-tiered chiffon cakes, cutesy cake pops and cupcakes, among others.

Ms Ng started baking 21/2 years ago, after tucking into chiffon cakes baked by her friends at potluck gatherings.

One month into baking them, she got bored with flavours such as pandan and orange.

"Chiffon cakes are usually baked in tube pans and look very plain. Why can't we make them more fanciful, with designs in their cross- sections such as those in Swiss rolls?"

Over the years, she has let her imagination run wild by giving chiffon cakes an innovative overhaul. She spoons the batter into hollow eggshells and paper cones to create oval- and cone-shaped chiffon cake pops.

Some of her more complex bakes include constructing a two-tier rainbow castle cake, complete with towers made from Swiss rolls, and topping it with cone- and rainbow- shaped cakes.

She has also baked a 70cm-tall princess cake, which features a gigantic cone-like "skirt" made of teal-blue chiffon studded with frills and lace trimmings.

"My research background has made me excited to challenge the boundaries of baking chiffon cakes," she says. "I get a kick from coming up with new cake designs."

The mother of three children aged between one and seven is married to a 36-year-old teacher.

She says: "After my career in science, I thought I would just become a housewife. I am grateful to have a second spring in life through baking."

  • Creative Baking: Chiffon Cakes costs $32 and is available at major bookstores.
A version of this article appeared in the print edition of The Sunday Times on February 21, 2016, with the headline 'The science of baking '. Print Edition | Subscribe