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Underproofed and overproofed look different in the oven

One bursts open at a random seam. The other spreads flat and barely springs. The bake tells you which mistake you made.

Why

An underproofed loaf still has plenty of gas-producing capacity left, so it expands violently in the oven and tears wherever it's weakest, often ignoring your score entirely. An overproofed loaf has exhausted much of that capacity and its gluten has been softened by accumulated acid, so it slumps sideways instead of upwards and the score stays shallow.

Further down

Underproofing usually gives a tight, uneven crumb with large irregular tunnels near the top. Overproofing gives a crumb that's uniformly small and slightly dense, sometimes with a visible flat area where it settled. Two different failures, two different pictures.

Words used here Crumb

Updated 7 October 2026