Orange Chiffon Cake

I love the lightness of sponge and chiffon cakes (= eat a lot of them cakes without getting sick), but making these cakes are quite difficult. My first attempt using an electric mixer and a tube pan yielded a bouffant sponge cake but with a coarse texture, but my second attempt was a total flop. I took it all in my stride as experiences to learn from, and my third attempt produced a chiffon cake that I am quite satisfied with. Light and fluffy with a fine texture and a subtle taste from the orange juice. I decided to make a chiffon cake rather than a sponge cake because chiffon cakes are moister and great to eat as is, whereas sponge cakes require some dressing up with cream, fruits, etc. Like most of the recipes I post to my online journal, I can't attribute this recipe to anyone in particular since I looked at several recipes to come up with this one.

Some notes about the recipe:
- Type of oil: I used extra light olive oil, although there are many who will tell you to avoid using olive oil for making chiffon cakes. Extra light olive oil is fine because it doesn't have a very strong aroma. EVOO (Extra Virgin Olive Oil) on the other hand is better for bread, salad dressing and pastas. Corn oil and canola oil are also quite odourless and would be good options to use in this recipe.
- Cream of tartar: So little of it is used in this recipe, yet it makes such a big difference when beating the egg whites to soft peaks. It stabilises and prevents the whites from drying out and collapsing prematurely. It is possible to do without cream of tartar, but your chance of succeeding improves a lot with it. Take it from a girl who has had many flops.
- Flour: I used 50:50 flour and cornflour (ie cornstarch, not the yellow stuff), but it's fine to use only flour. Cornflour gives a finer texture to the cake. Next time I might try using all cornflour.
- Technique: Mixing a quarter of the beaten egg white meringue to the flour/yolk batter lightens the batter considerably, which makes incorporating the two quicker and easier. It's something I picked it up from reading this book.
- Do not grease the tube pan! The batter needs to cling to the sides as it rises during the baking process in the oven.
- Quantity: I have an 18cm (7in) diameter tube pan (most recipes online use a 25cm (10in)), so the quantities listed here are for an 18cm pan - simply double the quantities for a 25cm pan, and increase the cooking time around 7-10minutes.
- Oven type: Convection (aka fan-forced) ovens are hotter than conventional ovens, so adjust the temperature and cooking time accordingly. My oven is convection.
- Cooling: Upon removing from the oven, this cake should be cooled upside down to maintain its height (some shrinkage will inevitably occur due to temperature difference), and this is where the tube pan comes in handy - the raised centre tube provides a good platform to stand on. This is also where leaving the pan ungreased comes in handy - the cake will not fall out of the pan while cooling upside down!

I'm now more confident and not so afraid of making these cakes. I'll keep on trying new techniques to improve the recipe, and I will definitely dabble with different flavours.

Ingredients
75g (~0.75 cup) flour, equal mix of all-purpose flour and cornflour
0.5 teaspoon baking powder
a pinch of salt
3 egg yolks
60mL (0.25 cup)orange juice
30mL (2 tablespoons) oil
80g (~0.75 cup) castor sugar
1 teaspoon vanilla extract
4 egg whites
0.25 teaspoon cream of tartar

Method
1. Preheat the oven to 160degC (convection).
2. Sift the flour and baking powder into a bowl, and combine with 65g of the sugar and the salt. Stir with a whisk until well combined.
3. In another bowl, combine the egg yolks, orange juice, oil and vanilla extract and whisk lightly to combine ingredients.
4. Add the wet mix to the flour mix and stir well until a smooth batter is obtained.
5. Place the egg whites in a large bowl and beat at high speed until foamy. At this point, add the cream of tartar, and continue beating whilst gradually adding the remaining sugar. Beat until stiff peaks form (when you pull out the whisk, the beaten egg whites should hold their shape and not droop - see here for a more detailed tutorial). Be careful not to overbeat or the whites will dry out and separate into two phases.
5. Add about 1/4 of the beaten egg whites to the egg yolk batter and stir well. Gently fold in the remaining egg whites to the batter, working lightly and slowly with a spatula until just blended (be careful not to deflate the mixture too much!)
6. Pour the batter into an ungreased 18cm (7in) tube pan and spread it out evenly.
7. Bake in the oven until golden brown, which took about 38 minutes for me. A good check is when the cake springs back when lightly touched.
8. Remove from the oven and invert pan until the cake is completely cooled (between 30mins and 1hr depending on the room temperature).
9. When it has cooled, use a thin knife to loosen the sides of the cake from the pan, and gently remove the cake from the pan;

First shot: the cake still attached to the middle tube of the pan; second shot: the underside of the cake looks nicer than its top!