Gelling With Gelatin

Gelatin – a fairly old ingredient for setting many items and cooking is also spelt as gelatine and originates from the French term, gélatine. It is a transluscent brittle substance, colourless or light yellow. In itself it has no taste or odour and it is created by prolonged boiling of connective tissue of animals such as skin, cartilege, and bones. Apart from its use in food, it is also of use in the pharmaceutical, cosmetic and photography industry. Technically also known as E number E441, it is an irreversibly hudrolyzed form of collagen.

Substances containing gelatin or functioning in a similar way are called gelatinous. Apart from culinary use, gelatin is also used in the pharmaceutical and makeup industry. Gelatin melts to a liquid when heated and solidifies when cooled again. Together with water, it forms a semisolid colloid gel. Gelatin forms a solution of high viscosity in water, which sets to a gel on cooling, and its chemical composition is, in many respects, closely similar to that of its parent collagen.

Gelatin is also soluble in most polar solvents. Gelatin gels exist over only a small temperature range, the upper limit being the melting point of the gel, which depends on gelatin grade and concentration and the lower limit, the freezing point at which ice crystallizes. The mechanical properties are very sensitive to temperature variations, previous thermal history of the gel, and time. The viscosity of the gelatin/water mixture increases with concentration and when kept cool. In addition to the animal gelatins described above, there are also vegetarian gelatins such as agar.

Gelatin in Food

Household gelatin comes in the form of sheets, granules or as powder. Instant types can be added to the food as they are; others need to be soaked in water beforehand. While the granular form of gelatin is easily available, the sheets are often sold only in large packaging making it suitable only for commercial users.

Special kinds of gelatin are made only from certain animals or from fish. In order to comply with food needs of the Jews and Muslims. Kosher (for the Jews) gelatin can be made with fish bones, and/or beef skins. Unlike other restrictions it is considered kosher to use it with dairy products. Kosher law is complex and the bones and hides used in gelatin production are considered ‘pareve’. It means foods that are neither milk nor meat. Some people assume this to mean that the product is ‘vegetarian’.