Observations and results
When you mixed together the wet and dry ingredients in the first bowl, "Mixed until combined-lumpy," you allowed the gluten proteins to become loose, mobile and perhaps begin to link to one another in a relaxed weblike network. When cooked, the chemical leaveners (the baking powder and baking soda) in the pancakes created large air bubbles. The loose gluten network captured the air bubbles and maintained the each pancake's shape while still keeping it fluffy with air.
In the second and third batches, overmixing the batter until smooth or very smooth overdeveloped the gluten. This means that the gluten organized itself into more tightly wound, side-by-side bonds in a very strong weblike network. So there is more of a tough gluten network than in the first batch, leaving less space for fluffy air pockets in between each gluten protein. The second and third batches of pancakes might have been a little tougher than the first batch. This is because there were fewer and smaller air pockets. You might have observed that the bubbles rising to the top of the pancakes during cooking were rose more slowly and were smaller than the large, frequent bubbles in the first batch of pancakes. You probably also noticed that the second and third batches spread out more on the pan when you poured the batter than did the first batch. This is because overmixing the batter allows for more of those gridlike side-by-side gluten bonds, which make the cooked pancake turn out flatter.
Eat any remaining pancakes—and share with helpers, family and friends.
More to explore
Chemical Reactions and Pancakes, from the Minnesota Science Teachers Education Project
Flat as a Pancake? Exploring Rising in Baked Goods, from the American Chemical Society
Chemistry of Gluten Proteins, from Food Microbiology
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