Directions:

1. Start by creaming together the sugar and butter. Then add the egg yolks one at a time, beating well after each addition.
2. Mix in the vanilla extract, lemon juice, and sour cream.
3. In a different bowl, combine the sifted flour, salt, and baking soda. Gradually add these dry ingredients to the wet batter, mixing thoroughly.
4. In another bowl, whip the egg whites until they form stiff peaks.
5. Gently fold the egg whites into the main batter. Transfer the mixture into a greased and floured tube pan.
6. Bake at 300°F for approximately 1 hour and 30 minutes, or until a cake tester comes out clean.