111 C H A P T E R 6 E X P E R I M E N T Procedure 1. Preheat the oven to 425°F. 2. Mass the flour, sugar, salt, and your assigned leavening agent. Combine these ingredients in a large mixing bowl. Variation 1: 7.0 g double-acting baking powder Variation 2: 3.5 g baking soda and 3.0 g cream of tartar Variation 3: 3.5 g baking soda and 30 mL vinegar, which should be added with the milk Variation 4: 3.5 g baking soda 3. Use the 100-mL graduated cylinder to measure the oil and milk. Combine these two ingredients with the egg (and vinegar in variation 3) in a small mixing bowl. 4. Make a well in the center of the dry ingredients. 5. Add the liquids all at once. 6. Stir the liquids into the dry ingredients with a wooden spoon until all the flour is moistened. Do not beat the batter will be lumpy. 7. Spoon the batter into 12 paper-lined cups of a muffin tin. Fill each muffin cup two-thirds full. 8. Bake the muffins 18 to 20 minutes. Muffins are done if the tops spring back when gently pressed. 9. Remove muffins from the tin. With a serrated knife, cut the muffins in half from top to bottom. Place the muffins on a plate and label with the variation number. 10. Select one sample of each variation. Evaluate each sample for cell size, color, and shape before taste testing. 11. Crumble one-fourth of a muffin of your variation into 50 mL of distilled water. Mix to make a smooth paste. Measure and record the pH of the paste. Questions 1. Which leavening agent produced the tallest muffins? Which produced the shortest? 2. Which leavening agent produced the best flavor? 3. Which, if any, of the variations have a bitter aftertaste? 4. Were there any differences in pH? If so, were the differences related to flavor or color differences?