Overview

Sweet and condensed milk (or sweetened condensed milk) is produced when sweetened milk is condensed to half its volume by removing part of the moisture in a vacuum evaporator. In order to ensure its preservation, sugar is added either at the beginning or during the concentration process. The high content of sugar in the resulting product increases the osmotic pressure to such a level that most of the microorganisms are destroyed. Thus, no sterilization takes place after canning or packaging.

Sweet and condensed milk has a shelf life of approximately 12 weeks provided storage conditions are cool and dry. It is used largely as the most popular source of milk solids for the sugar confectionery industry.

Sweet and condensed milk is whole milk, partly skimmed milk or skimmed milk from which approximately 50 percent of the moisture has been removed. It must contain no less than 28 percent milk solids and 8 percent milk fat if whole milk was the raw material. The condensed skimmed milk must not contain more than 0.3 percent fat. It must contain added sugar, dextrose, glucose, glucose solids or lactose in any combination. Vitamin D may be added, but the addition of vitamin A is mandatory.

The microbiological quality of the raw material for condensed milk is basically the same as required in the manufacture of ordinary milk products. The sugar concentration in the water phase must not be less than 62.5 percent or more than 64.5 percent. This saturated environment acts as a preservative so bacterial and mold growth can be controlled. At the latter level, the sugar solution reaches its saturation point and some sugar will then crystallize freely. If the crystals are too large, they impart an undesirable sandy texture. Microcrystalline lactose is therefore added to act as a seed, controlling the dimension of lactose crystals in such a small size that they cannot settle or be detected by taste.

Characteristics

• Appearance: Sweet and condensed milk is yellowish in colour and has a creamy and viscous appearance.

• Storage: Sweet and condensed milk can normally be stored for about three months at a temperature of 0-15^.C. Humidity of storage areas should be controlled below 50 percent to avoid the corrosion of the metal can. Inversion of the cans is a practical way to minimize the separation of fat and other constituents and to prevent the product from forming a surface cream line during extended storage. Prolonged storage (depending on storage conditions) may cause spoilage by sugar-fermenting yeasts, defects such as age thinning and age thickening. Swollen or blown cans indicate fermentation and spoilage and should not be used.

Various Uses

Sweet and condensed milks are used by the confectionery industry typically in caramel, toffee and fudge manufacture as well as in various desserts, ice cream, sauces, cake icings and bakery.

Functional Properties

Several desirable properties are achieved by incorporating condensed milk in product formulations. In fact, it is like adding whole milk in a sweet concentrated form. Consequently, the added sugars and the major components of milk, i.e. milk fat, proteins and lactose, will provide the following functional benefits:

Note: The profile for unsweetened condensed milk is similar to that of sweetened condensed milk except for the sugar content.