Angel Food Cake (Ver 2)

Ingredients
12 egg whites / 425ml
425g granulated sugar
140g cake flour
1 tbsp vanilla extract
2 tbsp lemon juice
1/4 tsp salt

Method

1. Adjust the oven rack to the middle position & preheat to 180 deg.C.  Sift cake flour & set aside.
2. Combine egg whites, sugar & vanilla extract in the bowl of a stand mixer fitted with the whisk attachment.  Mix on low (speed 1) about 1 min, then increase to medium-low (speed 4) & whip 3 mins; the whites will be dense & dark.
3. With the mixer still running, add lemon juice & salt.  Immediately increase to medium (speed 6) & whip 3 mins more; the meringue will be thin but foamy.  Increase to medium-high (speed 8) & continue whipping about 2-4 mins until the meringue is glossy white & thick enough the pattern left by the wire whisk.
4. Sprinkle cake flour on top & stir with a flexible spatula to roughly combine.  Switch to a folding motion, scraping from the bottom up & folding through the center until no pockets of flour remain.
5. Scrape the batter into a 10" aluminum tube pan & bake for 45 mins until the cake is puffed, golden & firm to the touch.
6. Invert pan onto its stilts & cool until absolutely no trace of warmth remains.  Slide an offset spatula around the sides of cake to loosen, remove the insert & slide spatula under the bottom as well.  Flip onto a serving plate.