Preheat the oven to 170°C. Do not coat or cover the mold in anything Add the egg whites and salt to bowl #1. Add the egg yolks and the sugar for the egg yolks to bowl #2. Place the sugar for the egg whites and the corn starch into small bowl #1. Add the oil, strawberry juice (Refer to Steps 2 and 5), and liquor to small bowl #2. Prepare the flour in a sifter.
Using a finely meshed strainer etc., mash up the strawberries and strain. Mix one teaspoon of the prepared strawberry juice with one teaspoon of the brandy, and prepare 70~80 ml. (I always prepare +80 ml. Using more allows you to enjoy the fragrance of the strawberries more, and it will become even more succulent, but it will shrink more after baking).
Using a clean bowl and a clean high-speed hand mixer free of water and oil, add in the egg whites and salt, and whip. After it has thickened and fonts a ribbon off the mixer, add in the powdered sugar and corn starch in over 2~3 turns, and whip. Use a low speed for the last turn, go once around the bowl, and adjust the consistency.
As for a measure of when the meringue is done, pick up a small amount of meringue from the bowl, and it should form a peak on the tips of the hand mixer blades. If the eggs are small, then add in another half portion of egg whites.
Place the egg yolks and powdered sugar into a separate bowl, and mix (you don't have to wash it) with a hand mixer. After it has turned white and thickened like in the photo, add in the vegetable oil and Step 2, and mix. Do not add in the remaining strawberry pulp from the sieve. The taste and texture will turn bad (speaking from experience...)
Add the flour to Step 5 in 2~3 batches while sifting. While turning the bowl, scoop up the batter with an egg beater, lift it up and drop it back in, take care not to knead it, and mix properly until the batter becomes uniform.
Add 1/3 of the meringue from Step 4 to the bowl from Step 6, and mix well with an egg beater. Return it to the bowl from Step 4, switch to a spatula, scoop it up from the bottom and fold it onto itself, quickly and gently mixing it. It will not expand if you over mix it, but if there are white lumps remaining from the meringue, then a cavity will form, and it will cave in.
As for how long to mix it, mix until the lumps of meringue are gone, and the batter becomes uniform. Step 7 shows in in a state of not being mixed enough. It will not plump up if you over mix it, but it will form air pockets in the cake, and will make a cavity when it cools, making it fall apart when you remove it from the mold. Let's mix it more-so than when mixing for a sponge cake.
Pour the batter into the mold from a height of about 30 cm. Rotate the pan once slowly while tilting it at an angle, and let the batter crawl over the edges of the mold (This seems to help it plump up, gain a foothold on the pan, and remove the air bubbles). You don't need to knock out the excess air in the pan. Immediately bake in an oven at 170°C for 25 minutes.
Just place the amount of batter that falls naturally into the mold. Do not scrape the bowl or spatula (batter that isn't mixed well will effect how well the cake rises). If you cook the remaining batter left in the bowl and on the spatula in a frying pan, you will be able to make one fluffy mini pancake like the one shown in the photo.
Take it out of the oven immediately after baking, drop the mold from a height of 30cm to prevent it from shrinking. Place it upside down on top of a bottle or rice bowl, and let cool in the mold. After it has cooled, covering it into a plastic bag while still in the mold will make it even more rich. Let cool completely while still in the mold.
Removing from the mold: The cake must be cooled before you start. Use a chiffon knife or a finely-serrated bread knife. While moving the knife up and down vertically with the teeth hitting the edges of the mold, go once around the circumference of the outer edges. In the same manner, go once around the center pipe. Remove the outer edge of the mold.
Place a knife between the bottom of the cake and the mold, starting from the outer edges and working your wary towards the center, trace halfway around the circumference, and go once around the edges while moving the knife back and forth. Place it onto the plate on which you will serve it, flip the mold upside down, and remove the cake.
To make milk tea flavored chiffon cake: Before beating the egg whites, place 2 tea packs into the a warmed cup from Step 1, pour in just enough water to soak it, cover with a lid such as a plate etc., and brew for the amount of time indicated on the tea package. Add anywhere from 1/2~2/3 milk to the cup.
Part 2: In place of the fruit juice in Step 5, add in 70 g of the milk tea you made. In addition, using tea leaves that have been finely ground in a mill or in a mortar, add a little less than 3 g (a little less than one very light teaspoon)~10 g. Use a small amount of high quality leaves, and use a lot if using normal tea. I also like adding in several drops of vanilla extract.
I use an aluminum mold. When using a paper, teflon or silicone chiffon mold or a paper muffin mold, then degree to which the cake shrinks away from the mold may vary. It'll be shriveled if you bake in a paper mold. If you are using anything aside from an aluminum mold, then use disposable paper cups! I also found that a stainless steel chiffon mold from the dollar store was tolerable.
User "Harukarubi" made a crème anglaise with the remaining egg yolk, and served it with her beautifully baked chiffon cake. She doubled the recipe amount in a 20 cm chiffon mold and baked for about 40 minutes! It has plumped up quite nicely.