Chart 1: Blood Sugar Curves of White Bread Compared Bread with Added Fiber, Sourdough, and Vinegar

Chart 2: Glycemic Index of Various Breads and Grain Products (Bread: 1 Slice; Sugar, 10 grams; Other, 50 grams) Source: Created using data from Textbook of Natural Medicine.

% of Phytic Acid Time (hours) Yeast Fermentation Sourdough Fermentation Source: R. Hauspy, "Fabrication du pain au levain naturel," Nature et Progres. Paris 1983, 1: Chart 3: Reduction of Phytic Acid in Whole Wheat Sourdough Bread

Chart 2: Sourdough's Moderating Role on Blood Sugar: Buckwheat Muffins with Varying Amounts of Sourdough Chart 3: Buckwheat Muffins, With and Without Sourdough; and With an Added Fat (Butter) Blood Sugar Index (mg/dL) / Change from Fasting Level 1)(Regular Buckwheat Muffin Recipe: 1/2 cup stone-ground whole wheat, 1/4 cup buckwheat) 2)(Regular Buckwheat Muffin Recipe: 1/2 cup stone-ground whole wheat, 1/4 cup buckwheat, 1/4 cup sourdough) 3)(Adapted Buckwheat Muffin Recipe: 1 cup sourdough; 1/4 cup buckwheat) 4)(Adapted Buckwheat Muffin Recipe: 3/8 cup First Clear; 1/4 cup buckwheat; 1/4 cup sourdough) 1)(Regular Buckwheat Muffin Recipe: 1/2 cup stone-ground whole wheat, 1/4 cup buckwheat) 2)(Regular Buckwheat Muffin Recipe: 1/2 cup stone-ground whole wheat, 1/4 cup buckwheat, 1/4 cup sourdough) 5)(Regular Buckwheat Muffin Recipe: 1/2 cup stone-ground whole wheat, 1/4 cup buckwheat) 6)(Heirloom stone ground whole wheat and rye made, 3 1/2 cups, 1 1/4 cup water, salt, and 1 cup sourdough.) (2) (3) (4) (1) (2) (5) Note concerning the recipes and procedure used to create the blood sugar curves that are illustrated above. The “meals” that were tested are variations on an Arrowhead Mills recipe for buckwheat muffins. The original recipe: ¾ cup buckwheat flour; ¾ cup whole wheat flour; 2 tsp. baking powder; ½ tsp. salt; 1 cup water; ¼ cup vegetable oil; 1 egg; and 5-6 Tbs. honey. My test recipe: I cut this recipe in half, used sourdough to soak the liquid and flour ingredients (not the baking powder or salt) for 16 hours, and then mixed in the egg, unrefined coconut oil, salt, and baking powder just before baking. 1)Buckwheat Muffins without Sourdough: This is the control case, the basic recipe, against which we can then assess the impact of sourdough under 2), 3), and 4). 2)Buckwheat Muffins with Sourdough: The original test recipe, with ¼ cup buckwheat flour, ½ cup stone ground whole wheat flour, ½ cup water, and ¼ cup sourdough, soaked 16 hours before adding the remaining ingredients. This test illustrates what sourdough might accomplish to curb the blood sugar effect of your favorite recipes if you added it and allowed it to soak overnight with the liquid and flour ingredients before adding the remaining ingredients and then baking. 3)Sourdough with Buckwheat: 1 cup sourdough (a combination of water and King Arthur First Clear flour); ¼ cup buckwheat flour; 1 tsp. baking powder; ½ egg, beaten; 1/8 cup oil; and salt. This recipe tests what happens to blood sugar using an extreme amount of sourdough. 4)Buckwheat with Sourdough: Same as above, but with ¼ cup buckwheat flour, 3/8 cup white First Clear flour; 3/8 cup water; and ¼ cup sourdough, soaked 16 hours before adding the remaining ingredients. This recipe replicates the flour used in 3) where white First Clear (an ideal high-ash flour to feed sourdough starter) is used in place of whole wheat flour. By keeping the flour ingredients identical to 3), we are testing 3) but under the condition of a lower, more normal ratio of sourdough. Procedure for testing the recipes: All tests were conducted as the day’s first meal after a 12-hour fast using a fixed three ounce serving and measured with a blood glucose monitor. Responses will vary with the individual. These are meant to give you a rough idea. You can have fun testing in your own kitchen. (6)