Isomalt in Food, Sugar Sculpture, and Cake Decorating
What Is Isomalt?
Isomalt is a low-calorie sugar substitute that tastes sweet but doesn’t cause tooth decay. Unlike sugar (sucrose), it has very little effect on the blood sugar level and is suitable for diabetics. It also has another advantage over sugar—it's a better material for making sugar sculptures.
Sculptures made from sugar are popular centerpieces, cake decorations, and art forms. They are also a great expression of creativity. Cooking sugar before using it enables artists to create stunning works of art that look as though they’re made of glass. Specialized art shows and competitions feature sculptures made from cooked sugar, isomalt, or a mixture of the substances.
Isomalt is often the preferred medium for sugar sculpture today. The general term for the art is still "sugar sculpture", however, even when a different sculpting medium is used. Even more confusingly, cake decorators often say that they are working with sugar when in fact they aren't. In all of the videos in this article, the word "sugar" actually refers to isomalt.
Using Isomalt in Food
Isomalt belongs to a family of chemicals known as the sugar alcohols. This family also contains maltitol, sorbitol, xylitol, and other substances. All of the sugar alcohols are used as sugar substitutes and none of them promote tooth decay. They are not related to the alcohol that we drink, despite the name of the family. If you are tempted to use xylitol as a sweetener, you should be aware that it can cause a deadly drop in blood sugar in dogs. The other members of the family don't have this effect.
Isomalt is an artificial chemical that's made from natural beet sugar (sucrose) and contains half the calories of sugar. It can be substituted for sugar in a one-to-one ratio in recipes. It isn't as sweet as sugar, however, and is sometimes combined with another sugar substitute, such as sucralose, to increase its sweetness
It's important to eat only small quantities of isomalt at first. Like most sugar alcohols, it can cause gastrointestinal distress, including stomach upset, flatulence, and diarrhea. Sugar alcohols are only partially absorbed into the body through the lining of the intestine. The molecules that remain in the intestine are fermented by bacteria, producing gas. Some people find that their digestive system gradually becomes tolerant of isomalt, but this doesn't happen to everyone.
Isomalt crystals are white in color and can be cooked like sugar crystals to make a sculpture medium. The substance is also sold in a precooked form that is ready for use after being briefly heated in a microwave oven.
Using Sticks and Nibs
Isomalt is often preferred to sucrose when making a sculpture, especially for a public display. It's easy to work with, produces a beautifully smooth and glossy finish, doesn't crystallize after being cooked, and resists damage from humidity better than sucrose.
Isomalt is available in solid sticks or nibs which are already cooked and are very convenient for making cake decorations. These are often more expensive than uncooked isomalt crystals, though. The sticks or nibs must be briefly heated in a microwave oven to liquify them. Food colors can then be added to create a colored liquid. Most sticks and nibs are sold with color already added.
The hot liquid can be poured into silicon molds and solidified to create interesting and attractive designs. Heat-proof gloves must be used when creating the decorations because liquid isomalt is very hot.
How to Cook Isomalt
Uncooked isomalt is sold as granules or crystals. These have the added benefit of acting as a food sweetener as well as a sculpture medium. The crystals can be cooked by placing them in a heavy saucepan on their own or with just enough water to make them look like wet sand. The mixture should be heated to at least 170°C or 340°F. Some cake decorators prefer to reach a temperature of 180ºC. A candy thermometer should be used to keep track of the temperature.
When the isomalt begins to boil, a pastry brush can be used to brush the splashes on the side of the pan back into the liquid. It's important to be careful when dealing with the hot liquid.
When the temperature goal is reached, the base of the saucepan should be placed in cold water just long enough to stop the cooking process and allow the bubbles to disappear.
Different pastry chefs have different ideas about the best time to add color to isomalt that is being cooked. A frequent recommendation is to add a water-based color at 140°C or 280°F and then to continue cooking.
Using and Storing the Substance
Liquid isomalt can be poured into a mold to set or shaped without a mold once it has cooled slightly and become more solid. In order to form a shape by hand, the hot liquid should be poured on to a marble surface or a silicon mat that has been lightly greased or sprayed with vegetable oil. Oiling a non-stick mat isn't necessary.
Cooked isomalt needs to be sculpted while it's still warm and before it completely hardens. If it becomes too cold and stiff it can be softened with a heat lamp. If it's going to be stored, it can be cooled and broken into pieces. The pieces should be placed in an airtight container with silica gel packets. These packets absorb moisture from the air, which is necessary because solid isomalt may become tacky when it absorbs water. The substance will stay in good condition for months or even for a year or more if the storage conditions are right.
Pulling and Blowing the Substance
When someone is ready to work with stored isomalt, the substance needs to be warmed with an infrared lamp or heated briefly by an alcohol burner to make it flexible. Broken pieces can be joined to each other by heating one piece to soften it and then pressing it on to the other piece.
In addition to pouring hot, cooked isomalt into molds, other techniques can be used to create interesting sugar sculptures. The cooked substance can be pulled and blown to create different shapes, textures, and appearances.
To pull a piece of isomalt, use one hand to hold one of the ends against a marble surface or a silicon mat. Pick up the other end with the other hand and pull away from the first hand. Then fold the stretched piece of isomalt back on itself. The substance behaves like taffy and becomes shinier the more often it's pulled.
The stretchiness of cooked isomalt allows it to behave like a balloon. Air can be pumped into a soft ball of the substance with a hand pump to expand the ball and create a bubble. The open end can then be sealed with heat. The video below gives more details about each step. It explains how to inflate the ball or bubble and how to keep it inflated.
Taking Care of the Sculptures
Isomalt sculptures are durable and long-lasting at room temperature. They don't melt or crystallize and maintain their form. It's important to keep them away from added heat, though, as well as from humid environments. Each of these factors may degrade the sculpture.
There is one very nice feature related to isomalt's ability to soften at high temperatures. If part of a sculpture breaks, it's easy to warm it, reshape it, and reattach it to the sculpture.
Isomalt can't be bought in supermarkets, at least in my part of the world, but is available at specialty stores such as ones that sell cake decorating supplies.
Creating Sculptures for Cake Decorations
It's very easy to begin using isomalt for cake decorations by buying precooked sticks or nibs, melting them, and then using silicon molds to form shapes. More advanced techniques are fun but require the purchase of special equipment like a heat lamp, a burner, a hand pump, and a silicon (or silicone) baking mat for the isomalt. Some sugar sculptors even use blowtorches to heat their isomalt. Of course, it's very important to be careful with lamps, burners, and blowtorches.
You may be able to find classes for sugar sculpture in your area if you're interested in learning more about this art form. Creating intricate sculptures requires practice. Training is very useful for learning new techniques and getting helpful tips from the instructor. Using molds is a great way to begin the creation of attractive decorations, however, and may be all that some people need or want. Whatever method is used, decorating cakes with isomalt is a fun and creative process.
© 2012 Linda Crampton