Japanese Chiffon Lemon Cheesecake

This is used to be my go-to cheesecake recipe back when I was in high school. Back then, Japanese cheesecakes used to be a big hit in Hong Kong. I have to admit, once you had a taste of it, you will never go back to the American style cheesecake! (sorry, I am a bit bias here, don't hate me all cheesecake fans). The ingredients are very basic, but the steps can be quite tricky. The humidity in the oven and the way you fold the egg whites are key factors that determine the success of the cake. Good Luck!

Ingredients: (yield as much as two 8" cake pans or two pound cake pans)

• 250ml milk
• 250 gm cream cheese, cubed and softened at room temperature
• 60 gm butter, softened at room temperature
• 6 egg yolks
• 20 g corn starch flour
• 55 g all-purpose flour
• 1 lemon zest
• 6 egg whites
• 1/4 tsp cream of tartar (optional)
• 130 g caster sugar (I will add more sugar since the eggs will dilute the sweetness) 

1. Preheat oven to 150C (302F).
2. Place the bowl over simmering water. Add cream cheese and milk, stir occasionally, until completely dissolved and the mixture turns smooth. Stir in butter, till dissolved. Remove from heat. Let cool down a bit, then add the egg yolks and combine well. (Note: Make sure the mixture is not too hot, as you don’t want to cook the egg yolks at this stage.)
   
3. Combine all-purpose flour and corn flour. Sift in the flours into the cream cheese mixture, mix in 1/3 amount at a time. Mix well between every addition, and make sure there aren’t any flour lumps. Stir in freshly grated zest. Set aside.
   
4. Place egg whites in a separate clean bowl. (Note: Make sure there’s no oil or water in the bowl at all.) Use an electric mixer to beat the egg whites for about 3 minutes, then add cream of tartar (optional) and blend again. Pour all the sugar in the egg whites and blend until very stiff peaks form
   
5. Fold-in the egg whites into the cream cheese mixture gently with a rubber spatula just until all ingredients are incorporated. Do not stir or beat. For a better result, fold in 1/3 of egg whites to the mixture and pour in the rest to incorporate
6. Pour the mixture into baking pans. Place the pans into another larger baking tray. Add hot water in the tray up to half way. Bake for about 50 to 60 minutes. Test with a needle or skewer that comes out clean
7. Turn off the oven. Leave the oven door ajar for 10 minutes. Remove from the oven and remove from the pans. Let cool completely on a wire rack. Chill in a fridge for about 3 hours before serving

 Tips

1. Beat egg whites: make sure you beat to a point that the egg whites won't fall when you flip the bowl upside down
2. Fold-in egg whites: make sure you fold from bottom to top and turn the bowl as you fold the mixture into the egg whites. Keep your motion fast while thorough so you don't break the air bubbles inside the whites
3. Make sure you mix the egg whites from bottom to top, so that the egg yolk batter doesn't sink to the bottom. Uneven batter will cause a heavy/stiff bottom after the cake is baked
4. Water bath baking: if your baking pan has a loose bottom, make sure you double wrap the bottom with aluminium foil before you place it in the water 
5. Water: make sure you add enough water so as it bakes, the surface of the cake remains smooth without cracks
6. Chill the cake before serve will help stabilize the cake and makes it more smooth and creamy. It's easier to cut through the cake as well