Gelatin is an odorless, tasteless thickening agent that forms a gel when combined with liquid and heated. It is thermo-reversible, which means that the gel liquifies when heated above its melting point but regains a jelly-like consistency when cooled again. The melting point of gelatin is close to the body temperature of the animal from which it is made, which for mammals is around 99F/37C.
The raw material for gelatin is collagen, a naturally occurring pure protein, which is commercially produced from bones, cartilage, tendons, skin and connective tissue of various animals. Gelatin can also be extracted naturally in the home, for instance when boiling bones to make a stock or aspic.
Common examples of foods containing gelatin are molded desserts, cold soups, trifles, aspic, marshmallows, and confectioneries such as Peeps, gummy bears, candy corn, and jelly beans. Gelatin may also be used as a stabilizer, thickener, or texturizer in foods such as jams, yogurt, cream cheese, and margarine. It is often added to reduced-fat foods to simulate the mouthfeel of fat and to create volume without adding calories. Additionally, gelatin is used for the clarification of juices and vinegar.
The term bloom with regard to gelatin can be a little confusing because it may be used in two different contexts.
One refers to the process of softening the gelatin in liquid prior to melting it. Recipes will often instruct you to bloom the gelatin in cold water for 5-10 minutes, which means to soak it.
You can bloom gelatin in just about any liquid. But you should avoid the fresh tropical fruit juices, such as papaya, kiwi, mango, and pineapple as they contain an enzyme (bromelin) that will break down the gelatin. However, pasteurizing kills the enzymes in these fruits, so canned or frozen juices are fine.
The other use of Bloom refers to the firmness of gelatin. A Bloom Gelometer, named after inventor Oscar T. Bloom, is used in a controlled process to measure the rigidity of a gelatin film. The measurement is called the Bloom Strength. A higher number indicates a stiffer product. Gelatin used in food usually runs from 125 Bloom to 250 Bloom. There are several different grades of sheet gelatin. The most popular are Silver grade (160 Bloom) and Gold grade (190220 Bloom). Typically the higher the Bloom, the more you can expect to pay.
Be aware that freezing gelatin will cause syneresis upon thawing. This is the disintegration of the gel, which is accompanied by the weeping of liquid from it.
This gelatin powder is made from farm-raised tilapia. It is a Type A gelatin of the highest quality. It is perfect for any recipe that calls for gelatin as well as for clarification. Note that fish gelatin has a lower gelling and melting point than gelatin produced from mammals (e.g. cow or pig skin).
