Evaporated milk consumes half the space of its nutritional equivalent in fresh milk. When the liquid product is mixed with a proportionate amount of water (125%), evaporated milk becomes the rough equivalent of fresh milk. This allows the product to have a shelf life of months or even years, depending upon the fat and sugar content, which made evaporated milk very popular before the age of refrigeration as a safe and reliable substitute for perishable fresh milk, as it could be shipped easily to locations lacking the means of safe milk production or storage.
As infant formula
In the 1920s and 1930s, evaporated milk became widely commercially available at low prices. The Christian Diehl Brewery, for instance, entered the business in 1922, producing Jerzee brand evaporated milk as a response to the Volstead Act.[4] Several clinical studies from that time period suggest that babies fed evaporated milk formula thrived as well as did breastfed babies.[5] However, modern guidelines issued by the World Health Organization consider breastfeeding, in most cases, to be healthier for the infant because of the colostrum in early milk production, as well as the specific nutritional content of human breast milk.[6]
Production
Evaporated milk is made from fresh, homogenised milk from which 60% of the water has been removed. After the water has been removed, the product is chilled, stabilised, sterilised and packaged. It is commercially sterilised at 240–245 °F (115–118 °C) for 15 minutes.[7] A slightly caramelised flavor results from the high heat process (Maillard reaction), and it is slightly darker in colour than fresh milk. The evaporation process concentrates the nutrients and the food energy (kcal); unreconstituted evaporated milk contains more nutrients and calories than does fresh milk per unit volume.
Additives
Evaporated milk generally contains disodium phosphate (to prevent coagulation) and carrageenan (to prevent solids from settling), as well as added vitamins C and D.
Reconstitution and substitution
Evaporated milk is sometimes used in its concentrated form in tea or coffee, or as a topping for desserts. Reconstituted evaporated milk, roughly equivalent to normal milk, is mixed one part by volume of evaporated milk with 1 1/4 parts of water.[1]
In the United States
According to the United States Code of Federal Regulations, Title 21, Chapter 1, Part 131, Sub part B, Section 130 "Evaporated milk", (April 2006):
(a) Description. Evaporated milk is the liquid food obtained by
partial removal of water only from milk. It contains not less than 6.5
percent by weight of milk fat, not less than 16.5 percent by weight of
milk solids not fat, and not less than 23 percent by weight of total
milk solids. Evaporated milk contains added vitamin D as prescribed by
paragraph (b) of this section. It is homogenized. It is sealed in a
container and so processed by heat, either before or after sealing, as
to prevent spoilage.
...
Sections (b)–(f) of the code regulate vitamin addition, optional ingredients, methods of analysis, nomenclature and label declaration.[8]
Canada
Evaporated milk in Canada is defined to be milk from which water has been evaporated and contains at least 25% milk solids and 7.5% milk fat. It may contain added vitamin C if a daily intake of the product contains between 60 and 75 milligrams, and may also contain vitamin D in an amount no less than 300 international units and no more than 400 international units. Disodium phosphate or sodium citrate (or both) may be added, as well as an emulsifying agent.[9]
Shelf life
The shelf life of canned evaporated milk varies according to both its added content and its proportion of fat. For the regular unsweetened product, a shelf life of 15 months may be expected before any noticeable destabilization occurs.[10]
^Marriott, William McKim; Schoenthal, L. (1929). "An experimental study of the use of unsweetened evaporated milk for the preparation of infant feeding formulas". Archives of Pediatrics. 46: 135–148.