What does deglazing a pan mean?

When you brown something in a pan, mushrooms, onions, a tray of vegetables, a spoonful of tomato paste, a layer of brown residue sticks to the bottom. It is not burnt food; it is the best part. Deglazing is the move that gets it back.

What the brown bits are

The browned layer is often called the fond. The cooking publisher ATK describes it as a direct result of the Maillard reaction, the browning in which heat turns proteins and natural sugars into new flavour compounds. Wikipedia's entry on deglazing) defines the technique simply: removing and dissolving browned food residue from a pan to flavour sauces, soups and gravies.

The colour matters. ATK's guidance is that the fond should be caramel-coloured to dark brown; once it turns black, the sauce will taste bitter. So deglaze while it is still brown, and if it is getting too dark, add a little water early and turn the heat down.

How to do it

1. Take out what you browned, or push it to one side if it is staying in the pan.
2. Pour off excess fat, leaving a thin film.
3. Add a splash of liquid to the hot pan. It will hiss and steam, which is the point.
4. Scrape with a wooden spoon or flat spatula, working over the whole base until the brown layer has dissolved into the liquid.
5. Simmer to reduce until it is syrupy enough to coat the spoon, then season and finish.

You do not need much liquid: enough to cover the base of the pan generously. You can always add more.

Which liquids work

• Wine. The classic. White wine for lighter dishes, red for deeper ones. Let it bubble until the raw alcohol smell softens before adding anything else. Leftover wine is perfect for this (more ideas here).
• Stock. Vegetable stock gives body and savoury depth. A stock cube dissolved in hot water is fine.
• Water. Underrated. It lifts the fond just as well and lets the flavour of what you browned speak for itself.
• Vinegar. A small splash of balsamic, red wine or cider vinegar gives a sharp, glossy finish. Use less than you would of wine.
• Spirits. Marsala, vermouth or a splash of brandy add sweetness and perfume. Take the pan off the heat before pouring, as they can catch light.
• Citrus juice. Lemon or orange, best combined with a little water or stock.

Wikipedia's entry advises against dairy at this stage, since it may curdle when it meets a very hot pan. Add cream or butter later, once the heat is lower.

What to make with it

• A quick pan sauce. Deglaze, reduce, then swirl in a knob of cold butter off the heat for gloss, or a thread of olive oil. Add herbs, mustard or capers. Spoon over vegetables, eggs or polenta.
• The base for a soup or stew. Deglaze after browning the onions and vegetables, then carry on with the rest of the liquid.
• Better risotto. Deglaze the toasted rice with wine before the stock goes in.
• Roasting tray gravy. Put the tray over the hob, add liquid and scrape up the caramelised edges left by roast vegetables.

The pan matters a little

Fond forms most readily in stainless steel, cast iron and carbon steel. Non-stick pans are designed to stop things sticking, so they leave less behind to deglaze. That is not a reason to change pans, only to expect a lighter sauce (see choosing a first frying pan).