Deglazing is a professional term used by chefs, for which no real everyday word has yet come into play. It is the technique of adding a liquid to a pan that has been used to brown food, either meat or veg, after the food has been removed. The pan is scraped so that the browned, flavourful bits are picked up by the liquid.
The French call the browned bits the “fonds.” These brown bits are actually carmelized sugars from the meat and vegetables. They form a rough “glaze” on the bottom of the frying pan. It is a great shame to waste them, as they are very flavourful. The flavoured liquid that is produced through deglazing makes one of the best bases for sauces. The added bonus is that you’ve also done some of the clean up for the pan.
If you are deglazing a frying pan, leave the heat on, but reduce it to medium if you’ve had it higher. If you are deglazing a roasting pan, removing the meat and set aside to rest, and place the roasting on a stovetop burner on medium. Make sure first that the roasting pan is study enough to stand direct heat.
Spoon or tip any excess fat out first. For the deglazing liquid, you can use water, stock, or alcohol such as wine, vermouth or beer, or juice such as lemon or onion juice, or verjuice. Some sources suggest that you shouldn’t use anything acidic such as wine or juice to deglaze a cast-iron pan, as it will pick up a metallic taste. In any event, use enough liquid to cover the bottom of the pan. Add the liquid, then scrape the pan well, to loosen up the browned flavour bits. After scraping, let it cook for a few minutes to reduce the liquid. Sometimes pieces of meat such as beef are dredged with flour before frying them, in which case the flavoured liquid will also be thickened from the flour left in the pan. You add this flavoured liquid to whatever dish you are making.
Deglazing is much harder to do in a non-stick pan, as you won’t get any browned particles sticking to the bottom of the pan in the first place.