Air Holes & Tunnels Inside
Here is a helpful solution to a common cause:
Ingredients were overmixed
- Overmixing is a common problem with muffins and is certain to happen with an electric mixer. Use only 15 to 20 light hand strokes with a spoon when combining the liquid and dry ingredients. There should be some lumps in the batter.
- To avoid other overmixing problems with muffins, first combine dry ingredients, mixing well. Then combine liquid ingredients, mixing well. Finally, combine dry and wet ingredients, by hand, using only 15 to 20 light strokes. There should be lumps in the batter.