They are light, airy and sweet confections. Homemade meringues are often chewy and soft with a crisp exterior, while many commercial meringues are crisp throughout. A uniform crisp texture may be achieved at home by baking at a low temperature (180–200 °F (82–93 °C)) for an extended period of up to two hours.
It has been claimed that meringue was invented in the Swiss village of Meiringen and improved by an Italian chef named Gasparini between the end of the 17th century and the beginning of the 18th century. However, this claim is contested; the Oxford English Dictionary states that the French word is of unknown origin. It is sure nevertheless that the name meringue for this confection first appeared in print in François Massialot's cookbook of 1692. The word meringue first appeared in English in 1706 in an English translation of Massialot's book. Two considerably earlier seventeenth-century English manuscript books of recipes give instructions for confections that are recognizable as meringue, though called "white biskit bread" in the book of recipes started in 1604 by Lady Elinor Poole Fettiplace (c.1570 – c.1647) of Gloucestershire and called "pets" in the manuscript of collected recipes written by Lady Rachel Fane (1612/13–1680) of Knole, Kent. Slowly baked meringues are still referred to as "pets" in the Loire region of France due to their light and fluffy texture.
There are several types of meringue: the sweetened, beaten egg whites that form the "islands" of floating island (also known in French as île flottante); the partly cooked toppings of lemon meringue pie and other meringue-topped desserts; and the classic dry featherweight meringue. Different preparation techniques produce these results.
Protein distribution in egg whites is as follows: (54%) ovalbumin, (13%) conalbumin/ ovotransferrin, (11%) ovomucoid, (4%) ovoglobulins, (3.5%) lysozyme, and (2%) ovomucin. Ovoglobulins drive foaming, ovomucin is the main stabilization agent, and the remainder of the proteins interact to contribute to overall foaming and stability. When egg whites are beaten, some of the hydrogen bonds in the proteins break, causing the proteins to unfold ("denature") and to aggregate non-specifically. When these egg white proteins denature (due to agitation from beating), their hydrophobic regions are exposed and the formation of intermolecular protein-protein interactions is promoted. These protein-protein interactions, usually disulfide bridges, create networks responsible for the structure of the foam and this change in structure leads to the stiff consistency required for meringues. The use of a copper bowl, or the addition of cream of tartar is required to additionally denature the proteins to create the firm peaks, otherwise the whites will not be firm. Plastic bowls, wet or greasy bowls will likely result in the meringue mix being prevented from becoming peaky. Wiping the bowl with a wedge of lemon to remove any traces of grease can often help the process.