Directions

1. Preheat oven to 325 degrees F (165 degrees C). Grease and flour a 10 inch tube pan. Mix together the flour and baking soda; set aside.
2. In a large bowl, cream together the butter and sugar until light and fluffy. Beat in the yolks one at a time, then stir in the lemon extract. Beat in the flour mixture alternately with the buttermilk, mixing just until incorporated. Pour batter into prepared pan.
3. In a large glass or metal mixing bowl, beat egg whites until stiff peaks form. Fold 1/3 of the whites into the batter, then quickly fold in remaining whites until no streaks remain. Pour batter into prepared pan.
4. Bake in the preheated oven for 90 minutes, or until a toothpick inserted into the center of the cake comes out clean. Let cool in pan for 10 minutes, then turn out onto a wire rack and cool completely.