A chafing dish is a covered dish that rests over a pan of water, which in turn is over a heat source. The heat source causes the pan of water to steam, which in turn keeps the food warm.
They are meant for use out of the kitchen.
Chafing dishes, because they are meant to keep food warm while it is being served, are often quite fancy. They can be used for keeping something warm at the table or sideboard, or cooking at the table or sideboard. To keep food chilled, conversely, you fill the water pan with ice and some water, and don’t turn on the heat source (obviously.)
The cover will be a roll top or a lift cover. More modern ones have vents in the lid to allow condensation to escape, helping to prevent food inside from getting soggy.
Modern ones are usually made of stainless steel. Other popular materials in the past have included chrome, silver, silverplate and copper. All require a good deal of polishing to look presentable. Manufacturers of even stainless-steel ones seem to recommended washing by hand.
For chafing dishes at home, the heat source is something like a Sterno can. Fill the water pan with hot water from the kettle. That way, your food won’t cool down while waiting for the water to have a chance to heat up. Don’t have your Sterno flame too high: you don’t want a vigorous boil that will cause water to boil out onto the table.
You can also buy electric ones.
Ones made for outdoor use have metal pans inside, teak coverings outside. The wood casing helps reduce loss of heat to outdoors wind, etc.
You can rent chafing dishes in many sizes for parties.
Very large, flat, shallow ones are used by caterers and in restaurants on buffet tables.
Chafing dishes were particularly popular around the turn of the 1900s. They allowed for meal preparation in spaces where there were no fully-equipped kitchens, and in that sense of convenience, they acted as perhaps the microwave or toaster ovens of today.
University students in dorms would be gifted one for cooking in their rooms, along with a book of recipes specially suited for chafing dish cooking. Young men and women getting their own rooms somewhere to enter the working world would often procure one to allow basic, economical meal preparation in their room.
“To-day no college-girl’s preliminary college outfit is complete without a chafing-dish — it is the sine qua non of her all-around popularity in the new life before her. Her first letters home contain rapturous accounts of savory concoctions devoured after study-hours by a dozen or more ‘simply famished’ friends, accounts which cause her mother to look anxious and her maiden aunt’s upper lip to stiffen perceptibly, as she exclaims, ‘How can any one stomach things cooked in a bedroom!'” — Sanford, Martha Cobb. “The Chafing Dish and the College Girl”. Woman’s Home Companion, April 1904.
Literature & Lore
“In the Winter we have things that are easily digested, cooked in the chafing dish. The boys enjoy that very much. Welsh rarebit is much more digestible than sweets, although many people look with horror upon it. My boy at college has a chafing dish, which he uses.” — A Talk with Mrs Rorer: Chunks of Wisdom from This Experienced Dietist. New York Times. 20 October 1891. Page 32.
“Chafing” comes from the French verb “chauffer”, meaning “to heat.”
The term is quite old, already extant by the start of the 1600s: “This streete is possessed for the most part by Founders, that cast Candlestickes, Chafingdishes, Spice mortars, and such like.” [‘Colemanstreete warde’, A Survey of London, by John Stow: Reprinted from the text of 1603 (1908), pp. 276-285]