Gelatin dessert

Gelatin desserts are desserts made with sweetened and flavored gelatin. They can be made by combining plain gelatin with other ingredients or by using a premixed blend of gelatin with additives. Fully prepared gelatin desserts are sold in a variety of forms, ranging from large decorative shapes to individual serving cups.
==Brands==
Popular brands of premixed gelatin include:
*Hartley's in the United Kingdom (although most Hartley's Jellies are, since their acquisition from Rowntree's, made without Gelatin, see Gelatin Substitutes below)
*Jell-O from Kraft Foods in North America
*Aeroplane Jelly in Australia
*Royal in Spain, Portugal and Latin America
*Moir's and Trotters in South Africa and Swaziland
==Preparation==
To make a gelatin dessert, gelatin is dissolved in hot liquid with the desired flavors and other additives. These latter ingredients usually include sugar, fruit juice, or sugar substitutes; they may be added and varied during preparation, or pre-mixed with the gelatin in a commercial product which merely requires the addition of hot water.
In addition to sweeteners, the prepared commercial blends generally contain flavoring agents and other additives, such as adipic acid, fumaric acid, sodium citrate, and artificial flavorings and food colors. Because the collagen is processed extensively, the final product is not categorized as a meat or animal product by the US federal government.
Prepared commercial blends may be sold as a powder or as a concentrated gelatinous block, divided into small squares. Either type is mixed with sufficient hot water to completely dissolve it, and then mixed with enough cold water to make the volume of liquid specified on the packet.
The solubility of powdered gelatin can be enhanced by sprinkling it into the liquid several minutes before heating, "blooming" the individual granules. The fully dissolved mixture is then refrigerated, slowly forming a colloidal gel as it cools. 
Gelatin desserts may be enhanced in many ways, such as using decorative molds, creating multicolored layers by adding a new layer of slightly cooled liquid over the previously-solidified one, or suspending non-soluble edible elements such as marshmallows or fruit. Some types of fresh fruit and their unprocessed juices are incompatible with gelatin desserts; see the Chemistry section below.
When fully chilled, the most common ratios of gelatin to liquid (as instructed on commercial packaging) usually result in a custard-like texture which can retain detailed shapes when cold but melts back to a viscous liquid when warm. A recipe calling for the addition of additional gelatin to regular jelly gives a rubbery product that can be cut into shapes with cookie cutters and eaten with fingers (called "Knox Blox" by the Knox company, makers of unflavored gelatin). Higher gelatin ratios can be used to increase the stability of the gel, culminating in gummy candies which remain rubbery solids at room temperature. (See Bloom (test).)
===Gelatin shots===
A gelatin shot (usually called a Jell-O shot in North America and vodka jelly or jelly shot in the UK and Australia) is a shooter in which liquor, usually vodka, rum, tequila, or neutral grain spirit replaces some of the water or fruit juice that is used to congeal the gel.
The American satirist and mathematician Tom Lehrer has been rumored to have been the first to invent the gelatin shot in the 1950s while working for the National Security Agency, where he developed vodka gelatin as a way to circumvent a restriction of alcoholic beverages on base, but the claim that he was first is untrue. The earliest published recipe dates from 1862, found in How to Mix Drinks, or The Bon Vivant's Companion by Jerry Thomas: the recipe calls for gelatin, cognac, rum, and lemon juice.
The maximum alcohol content is somewhere between 19-20 fl oz (562-591 mL) of vodka mixed with a 3 oz (85 g) package of gelatin powder dissolved in 4 fl oz (118 mL) of boiling water; the resulting solution has about 30% alcohol by volume.
===Gelatin substitutes===
Other culinary gelling agents can be used instead of animal-derived gelatin. These plant-derived substances are more similar to pectin and other gelling plant carbohydrates than to gelatin proteins; their physical properties are slightly different, creating different constraints for the preparation and storage conditions. These other gelling agents may also be preferred for certain traditional cuisines or dietary restrictions.
Agar, a product made from red algae, is the traditional gelling agent in many Asian desserts. Agar is a popular gelatin substitute in quick jelly powder mix and prepared dessert gels that can be stored at room temperature. Compared to gelatin, agar preparations require a higher dissolving temperature, but the resulting gels congeal more quickly and remain solid at higher temperatures, , as opposed to for gelatin. Vegans and vegetarians can use agar to replace animal-derived gelatin.
Carrageenan is also derived from seaweed, and lacks agar's occasionally unpleasant smell during cooking. It sets more firmly than agar and is often used in kosher and halal cooking.
Konjac is a gelling agent used in many Asian foods, including the popular konnyaku fruit jelly candies.