Bread error!

I wonder if it might be over proofed due to too much yeast or whole grain which can speed up proofing. I remember making loaf after loaf trying to tweak a honey oatmeal bread. It took about seven loaves before I got it right. The amount of yeast and water was key.

I still get the odd dud but most of the time it works great. The only thing is that I now much prefer my hand made sourdough breads so I rarely make that bread anymore. Although I should try baking it in a Dutch oven and see what happens. Hey, thanks for the idea!

My guess would be that a small gas bubble deposited itself at that end of the loaf and never got popped during the maturation/shaping/proofing (handling) phase. Little bubbles can become great big ones if they meet with no resistance.

Not knowing much about bread machines I'm guessing that the dough probably didn't move around much during the needing phase. Your bread machine might not tolerate the new recipe.