In a large bowl, beat the egg whites until foamy. Add the water, cream of tartar, vanilla and 2 teaspoons of the lemon juice and beat at medium-high speed until soft peaks form. Gradually add the lemon sugar and beat until the whites are stiff and glossy. Fold in the flour mixture in 3 batches. Spoon the batter into an angel food cake pan with a removable bottom and smooth the top. Using a knife, cut through the batter several times to release any air bubbles. Bake the cake for about 45 minutes, or until the top is golden and feels springy. Invert the cake pan onto the neck of a wine bottle and let the cake cool completely.