Bread

A 'flying top' when the top crust breaks away from the loaf: Under-proving.  Dough surface dried out during proving. Oven too hot.

Crust splits at one side of the loaf: Loaf baked too near side of oven. 

Loaf has a flat top: Flour too soft.  Too little salt.  Dough too wet.  Poor shaping of dough.

Crust surface cracks after removal from oven:  Over-proving.  Oven too hot.  Cooling in draught after baking. 

Dough collapses when put into oven: Over-proving.

Heavy, close texture.  Poor volume:  Flour too soft.  Too much salt.  Insufficient kneading or proving.  Yeast killed by rising in too hot a place.

Coarse, open texture: Too much liquid.  Over-proving.  Oven too cool.

Uneven texture with large holes:  Dough not knocked back properly.  Dough left uncovered during rising.

Sour, yeasty flavour and smell of alcohol: Over-proving. Too much yeast.  Stale yeast or fresh yeast creamed with sugar.

Bread stales quickly and is crumbly:  Too much yeast.  Flour too soft.  Rising too quickly in too warm a place.  Under-rising. Over-proving.