Combine egg whites, cream of tartar and salt. Beat to very soft peaks. Turn mixer to lowest speed and gradually add sugar 1 teaspoon at a time. Then add flour 1 teaspoon at a time. Do not overmix.
Fold in vanilla, almond extract and lemon juice. Transfer to non-stick angel food cake pan. Bake on bottom rack of 350 degrees oven 45-50 minutes or until cake is golden and cracks on top feel dry.
Invert pan and let cool. Remove onto serving platter.
To make chocolate angel food cake, leave out lemon, add ½ cups of fat.
