Rescues · TO DEGLAZE
The pan warped or the base cracked.
Why it happens
Cold liquid into a very hot thin pan. Thermal shock; use a heavy pan, or take it off the heat for a moment first.
Recovering it
Under-deglazed is trivially fixed — add more liquid and keep going, the fond is still there. Bitter fond cannot be recovered once dissolved; the honest move is to pour the liquid away, wipe the pan and accept the loss, because that bitterness will not cook out. If the alcohol tastes raw, simply keep reducing: the fix and the failure are the same step done for longer.
The mechanism
When food browns in a pan, some of the Maillard products — the aromatic compounds created by the reaction between amino acids and sugars — polymerise and stick to the metal as a dark layer called fond. Most of them are water-soluble, so they dissolve readily the moment liquid arrives and heat helps them let go. What looks like a pan needing to be scrubbed is in fact the most concentrated flavour in the dish. Any liquid works — wine, stock, water, even the water clinging to vegetables — because the mechanism is solubility rather than acidity. Alcohol contributes a little extra by dissolving some aromatic compounds that water alone will not, but it is not the reason the technique works.
The full TO DEGLAZE lesson — how to tell, where to practise it, what it carries to.