What is Gelatin?
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 liquefies 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. Much of commercial gelatin today is a by-product of pigskin. 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.
Because gelatin is derived from animal hide and bone there are problems with regard to kosher and Halal status and many vegetarians also have objections to its use. In these cases, alternative choices include agar agar, guar gum, xanthan gum, pectin and kudzu.
What is Sheet/Leaf Gelatin?
Sheet Gelatin, also called Leaf Gelatin, works like granular gelatin found in your local grocery store, but in a different form. Rather than a powder, it is takes the shape of thin sheets or leaves of gelatin film. The sheets dissolve more slowly than the granulated form, but also produce a clearer gelled product.
Why Most Professionals Prefer Sheet/Leaf Gelatin over Powdered Varieties like Knox?
Professional cooks often use sheet/leaf gelatin because it makes a clearer gelatin with purer flavor. Many chefs also prefer sheets for ease of use. They allow for the counting of leaves rather than weighing out powder and there is no chance of undissolved granules. European recipes typically call for the use of leaf gelatin.
You can successfully substitute sheet gelatin for powdered gelatin in any recipe by using the following scaling.
1 (0.25 oz.) envelope granulated gelatin = 1 tablespoon powdered gelatin = 3 sheets leaf gelatin.
Whats the Deal with Bloom?
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.
How to use Sheet/Leaf Gelatin
Basic steps for using gelatin sheets:
- Soak sheets of gelatin in a bowl of cold/iced water for 5 to 10 minutes. (Use about 1 cup/250ml of cold water per sheet.)
- Once soft, lift sheets from the cold water.
- Wring gently to remove excess water.
- Add sheets to room temperature liquid called for in the recipe. Heat the mixture, stirring until the gelatin is dissolved. Do not boil or gelatin will not set. Do not add chilled liquids or mixtures to gelatin after it is dissolved or it will cause uneven setting.
Typical usage amounts:
- 3 Leaves Gelatin to 2 cups/500ml Liquid = Delicate Gel
Desserts made with gelatin should chill for at least eight hours, but twenty four hours is best. After twenty four hours, gelatin will not set any further.
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.
Why Buy Gelatin Sheets/Leaves from Modernist Pantry?
Our silver sheet gelatin is made in Germany from pork skin. It is a Type A gelatin, weighing approximately 2.5g per sheet. Our German-made sheets are the standard that chefs and recipes call for around the world.
Ask a Chef: The Confusion over Conversion