Bain-marie

A bain-marie (also called a double boiler) is a device used in science, industry and cooking to heat materials gradually to a fixed temperature or to keep materials warm over a period of time.

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Description

The bain-marie consists of a large container filled with a working liquid (usually water) and another, smaller container filled with the substance to be heated. The smaller container is partially immersed in the larger container, and the larger container is heated. The temperature of the working liquid cannot normally exceed the boiling point of that liquid at the ambient atmospheric pressure, and so the temperature of the inner container can be brought to a known limit and held there by bringing the outer working liquid to a boil. Convection in the working liquid of the outer container also improves the uniformity of heating in the inner container. When the working liquid is water and the bain-marie is used at sea level, the maximum temperature of the inner container will not exceed 100 degrees Celsius (the boiling point of water at sea level). Other working liquids (oils, salt solutions, etc.) can be used to change this maximum temperature.

Nowadays, there is a 'dry alternative' to the rather standard, liquid filled bains-marie, requiring no liquids to be filled into them and instead just have a heater element below the pots. 'Dry Heat' Bains Marie also consume less energy, require less maintenance such as cleaning etc., heat up faster, able to operate at higher temperatures and are around 1/4 cheaper than typical 'Wet Heat' ones.^{[citation needed]}

Culinary applications

• Cheesecake is generally baked in a bain-marie to prevent the top from cracking in the center.
• Custard may be cooked in a bain-marie to prevent a crust from forming on the outside of the custard before the interior is cooked.
• Melting of chocolate for use in topping of various dishes.
• Dehydration and thickening of condensed milk to make several milk-sweets.
• Controlled-temperature bain-marie is recommended to lukewarm freeze-stored breast milk when timely breastfeeding is not possible, according to breastfeeding advocates.

It is also used for holding large quantities of food for service.

Terminology

The term bain-marie originates from alchemy, where some practitioners needed to give their materials prolonged periods of gentle heating, in an attempt to mimic the supposed natural processes whereby precious metals germinated in the earth. It was said to be an invention of Mary the Jewess, an ancient alchemist traditionally supposed to have been Miriam, a sister of Moses. The name comes from this tradition: balneum Mariae in medieval Latin, from which the French bain de Marie is derived.

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