In archaeology or anthropology, a pot boiler or cooking stone is a heated stone used to heat water - typically by people who did not have access to pottery or metal vessels.
In archaeology or anthropology, a pot boiler or cooking stone is a heated stone used to heat water - typically by people who did not have access to pottery or metal vessels.
The term refers to a stone used to move heat from a fire to a vessel to raise the temperature of water in the vessel, including for cooking. The stone is heated in a fire or in embers. When hot enough, the stone is transferred into a vessel of water to heat the contents. The vessel may be metal (though this is uncommon, metal normally being tough enough to take direct heat from a fire) or pottery which is not of good enough quality to be directly exposed to the heat of the fire [1] - or a wooden trough. [2] In a pre-pottery context, the heating can be done by lining a pit with leather, leaves or clay, and then putting in the water followed by pot boilers directly into the vessel. [3] [4] [5] [6]
Such stones can be recognized because the repeated exposure to the heat of the fire followed typically by rapid chilling in water leads to great thermal stress on the stone's fabric due to the thermal expansion and contraction. This typically leads to partial glazing of the stone's surface and a fine network of cracks on the stone's surface (often described as "crazing"). Eventually the stone shatters. Individual fragments may be re-used until it becomes infeasible to manipulate the stone into and out of the fire, at which point the fragments are discarded and a new pot boiler (or many new ones) are acquired. Often the broken pot boilers are discarded into middens or domestic waste deposits, which on long-established sites can amount to many tonnes of material. [2]
Reuse as building material is not impossible, but the typical small size of the fragments hinders this use.
Surface "crazing" is not restricted to pot boilers - hearth stones and the surrounds of fireplaces may also show the same structure. However, since a pot boiler needs to be manipulated into and out of the fire (typically in anthropological observations, using sticks of green wood) at arm's length, they start off weighing up to several kilogrammes, and shrink by fragmentation ; hearth stones and chimney liners are typically larger.
A bain-marie, also known as a water bath or double boiler, a type of heated bath, is a piece of equipment used in science, industry, and cooking to heat materials gently or to keep materials warm over a period of time. A bain-marie is also used to melt ingredients for cooking.
A kiln is a thermally insulated chamber, a type of oven, that produces temperatures sufficient to complete some process, such as hardening, drying, or chemical changes. Kilns have been used for millennia to turn objects made from clay into pottery, tiles and bricks. Various industries use rotary kilns for pyroprocessing and to transform many other materials.
A wok is a deep round-bottomed cooking pan of Chinese origin. It is believed to be derived from the South Asian karahi. It is common in Greater China, and similar pans are found in parts of East, South and Southeast Asia, as well as being popular in other parts of the world.
Boiling or ebullition is the rapid phase transition from liquid to gas or vapor; the reverse of boiling is condensation. Boiling occurs when a liquid is heated to its boiling point, so that the vapour pressure of the liquid is equal to the pressure exerted on the liquid by the surrounding atmosphere. Boiling and evaporation are the two main forms of liquid vapourization.
A microwave oven or simply microwave is an electric oven that heats and cooks food by exposing it to electromagnetic radiation in the microwave frequency range. This induces polar molecules in the food to rotate and produce thermal energy in a process known as dielectric heating. Microwave ovens heat foods quickly and efficiently because excitation is fairly uniform in the outer 25–38 mm(1–1.5 inches) of a homogeneous, high-water-content food item.
In archaeology, fire-cracked rock (FCR) or fire-affected rock (FAR), is rock of any type that has been altered and split as the result of deliberate heating. It is a feature of many archaeological sites. In many cases, fire-cracked rock results when stones were used to line hearths and earth ovens or were heated to provide a longer-lasting heat-source.
A boiler is a closed vessel in which fluid is heated. The fluid does not necessarily boil. The heated or vaporized fluid exits the boiler for use in various processes or heating applications, including water heating, central heating, boiler-based power generation, cooking, and sanitation.
Cookware and bakeware is food preparation equipment, such as cooking pots, pans, baking sheets etc. used in kitchens. Cookware is used on a stove or range cooktop, while bakeware is used in an oven. Some utensils are considered both cookware and bakeware.
Water heating is a heat transfer process that uses an energy source to heat water above its initial temperature. Typical domestic uses of hot water include cooking, cleaning, bathing, and space heating. In industry, hot water and water heated to steam have many uses.
A stove or range is a device that generates heat inside or on top of the device, for local heating or cooking. Stoves can be powered with many fuels, such as electricity, natural gas, gasoline, wood, and coal.
A central heating system provides warmth to a number of spaces within a building from one main source of heat. It is a component of heating, ventilation, and air conditioning systems, which can both cool and warm interior spaces.
A fire-tube boiler is a type of boiler invented in 1828 by Mark Seguin, in which hot gases pass from a fire through one or more tubes running through a sealed container of water. The heat of the gases is transferred through the walls of the tubes by thermal conduction, heating the water and ultimately creating steam.
Induction cooking is performed using direct electrical induction heating of cooking vessels, rather than relying on indirect radiation, convection, or thermal conduction. Induction cooking allows high power and very rapid increases in temperature to be achieved: changes in heat settings are instantaneous.
A steam explosion is an explosion caused by violent boiling or flashing of water or ice into steam, occurring when water or ice is either superheated, rapidly heated by fine hot debris produced within it, or heated by the interaction of molten metals. Steam explosions are instances of explosive boiling. Pressure vessels, such as pressurized water (nuclear) reactors, that operate above atmospheric pressure can also provide the conditions for a steam explosion. The water changes from a solid or liquid to a gas with extreme speed, increasing dramatically in volume. A steam explosion sprays steam and boiling-hot water and the hot medium that heated it in all directions, creating a danger of scalding and burning.
Fulacht fiadh is the name given to one of many burned mounds, dating from the Bronze Age, found in Ireland. Most surviving examples consist of a low horseshoe-shaped mound of charcoal-enriched soil, and heat-shattered stone, with a cooking pit located in a slight depression at its centre. In ploughed fields, they are apparent as black spreads of earth interspersed with small sharp stones.
A masonry heater is a device for warming an interior space through radiant heating, by capturing the heat from periodic burning of fuel, and then radiating the heat at a fairly constant temperature for a long period. Masonry heaters covered in tile are called cocklestoves. The technology has existed in different forms, from back into the Neoglacial and Neolithic periods. Archaeological digs have revealed excavations of ancient inhabitants utilizing hot smoke from fires in their subterranean dwellings, to radiate into the living spaces. These early forms have evolved into modern systems.
An instant hot water dispenser or boiling water tap is an appliance that dispenses water at about 94 °C (201 °F) (near-boiling). There are hot-only and hot and cool water models, and the water may be filtered as well as heated. Instant hot water dispensers became popular in the 1970s. Instant hot water dispensers are very similar to portable shower devices; the latter is fitted with a heating element and quickly heats up water, once a switch has been activated.
A thermal cooker, or a vacuum flask cooker, is a cooking device that uses thermal insulation to retain heat and cook food without the continuous use of fuel or other heat source. It is a modern implementation of a haybox, which uses hay or straw to insulate a cooking pot.
Stone boiling is a moist-heat cooking method. It involves placing heated rocks into a water-filled container to heat the liquid to the point where it can be used to cook. This method of food preparation is a fuel-intensive process and it often requires the heating and reheating of stones before the water reaches an effective cooking temperature.
The hearth fire has handed down one relic of antiquity, the ' pot-boiler '. The pot-boiler was a roughly rounded stone, usually flint, which was made red hot and then flung into the water contained in the primitive cauldron or in a puddled hollow in the soil. By this means flesh was boiled, however inefficiently. Or, again, the meat was grilled or baked over the heated stones. The use of the pot-boiler for heating water was continued until late in the historic period.
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