Making of Indian Desserts

In the olden days, the sweet makers were known as 'Halwai'. Each village, no matter how small had a Halwaii shop. The temples have their own Halwaii, who make sweets and pass them out as blessings known as Parshad. Most of the sweets are made from dairy products, grains or beans/lentils. The most common bean used is Garbanzo beans (Chana). Dried fruits such as raisins and nuts (specially pistachios and almonds) are used for garnishing and texture. Savory spices such as cardamom seeds, fennel seeds, nutmeg, cinnamon are used for aroma. Flowery scent is added from sandalwood, Khas (Vetiver), Kewra (Screwpine) and rose water.

Role of Sugar

The word "sugar" has its roots in Sanskrit word 'Sharkara'. Sugar physics plays a major role in making desserts. Raw sugars such as Honey, Sugarcane Jaggery and Palm Jaggery are used as sweeteners. The raw sugars are basically Glucose and Fructose, also known as Inverted Sugars. Refined sugars such as Granulated table sugar and confectioners sugar are basically Sucrose. You can convert sucrose to inverted sugar by subjecting it to acid and heat. Inverted sugar has following properties.
1. Partially inverted sugar tastes sweeter than pure Sucrose or pure Glucose/Fructose..
2. Inverted sugar has a high humectancy, making the desserts more moist.
3. Lower crystallization.
4. Lower viscosity.
5. Freezing Point Depression
As the sugar density rises...
The normal freezing point of water is 32º F and the boiling point is 212º F. As the sugar is added to the water, the freezing point depresses (gets lower), and the boiling point gets higher. The change in freezing point and the boiling point are not linear to the amount of sugar. Also, it varies with barometric pressure as well as the water and sugar impurities. These physical properties can lead to formation of Ice Crystals in making ice-cream and Sugar Crystals in the syrup.

Ice Crystals

The major problem in making ice cream/Kulfi is the formation of ice crystals. There are two primary culprits; the dairy product and the sugar. 
The dairy products in United States are homogenized by mechanically reducing the size of fat granules. As the dairy product is frozen, the surface tension is broken making fat granules larger and makes them float over the skimmed water content.
Normal freezing point for water is 32º F. Sugar lowers this freezing point. Use of inverted sugar makes it lower further. Also, as the water content starts to freeze, the sugar density rises, making the problem worse. The freezing point for a typical Ice Cream is about 25º F. This phenomenon causes the formation of Ice Crystals.
To avoid formation of ice crystals, you have to follow three steps:
1. Cook the ice cream mixture that contains dairy product to at least 165º F.
2. Age the mixture overnight (about 12 hours) the refrigerator prior to start freezing.
3. Freeze as quickly as possible. This is done in the manual ice makers by adding salt to the ice. 1 cup of salt to 5 cups of ice lowers the freezing temperature to about 16º F.

Sugar Syrups

In India, sugar syrup is called "Chasni". The technology has evolved from using raw sugars to refined sugars; however, the method to check sugar density has remained constant. Candy thermometers are hardly used. The Tar (Thread) method is used to determine the sugar density. While making Chasni, a drop of the mixture is pinched between the thumb and the index finger and released to see  how many threads are made. I will put the Tar Method in terms of Standard Candy making terms. For this purpose, I will assume that the Chasni is made using Refined sugar and water without any acids (fruit juices or lime etc.).

At room temperature, you can dissolve sugar to 50% of its weight in water. You can increase the amount of sugar by increasing temperature. After the solution comes to a boil eventually you can not dissolve any more sugar. But continued heat evaporates water making the syrup more concentrated. The sugar concentration determines the eventual texture and consistency of the product.

Substituting part of the sugar with glucose syrup improve keeping quality

Simple Syrups

This syrup is normally lower than 60% sugar density. The syrups are made with refined sugar. Lime juice or cream of tartar is added before cooking to partially invert the sugar. Typical examples are Rasgulla and Gulab Jamun. 
To avoid sugar crystallization:
1. Do NOT stir syrup while the sugar is being consumed by water during syrup making.
2. After the sugar has has been consumed, shock the syrup temperature.
Example Simple syrup

Step 1: In a stainless steel heavy bottom pan, add water, sugar and lemon juice. Heat without stirring till all the sugar is consumed. Let it come to a boil. Continue boiling for one minute.
Step 2: Shut off heat. Add cold water to shock syrup. Stir. Let it cool.

To avoid under cooking of the dessert

If the syrup sugar density is high, it hinders the dessert itself from cooking as the penetration of the liquid is slow. To avoid this, do two-step method. In the first-step only add 1/4th of the needed sugar. Cook your dessert. Remove the dessert from the syrup. Add the remaining sugar to complete making of the syrup. Re-introduce the dessert.

Puffing up of Desserts

Baking soda/powder are used for leavening (introducing air) into the product to make them seem light.
To understand this process, we have to understand a bit of chemistry called the pH factor. pH factor ranges from 0 to 14. Foods above 7 are alkaline, under 7 are acidic. pH = 7 is neutral. Just as a trivia, the pH = 7.35 for average human body, slightly alkaline. When the acid is mixed with alkaline, gas (carbon dioxide) is formed, when interspersed within the food, makes them airy, puffy or light.
Almost all grain products (Wheat, Corn, Rice, Chickpeas) are slightly acidic (Average pH = 6.1). Buckwheat (Kuttu) and Millet (Bajra, Jowar, Ragi) are the only grains that are slightly alkaline (Average pH = 7.4). Baking soda (Sodium Bi-Carbonate) is alkaline. So, when Baking soda is sifted with Wheat four and moisture is introduced, dough gets fluffy. However, when the baking soda is sifted with Bajra flour and water the dough does not become fluffy. On the other hand, if cream of tartar (Acid) is sifted with millet flour and with moisture, the dough gets fluffy. Summary follows:

Cream of Tartar

This is an acid. When mixed with alkaline and moisture, it forms gas.
Baking Soda: This is an alkaline. When mixed with acid and moisture, it forms gas.
Baking Powder (Single Action): This is a combination of cream of tartar and baking soda. When mixed with moisture, it creates gas. Corn starch is added as a drying agent to prevent accidental activation.

Baking Powder (Double Action)

This is a combination of Baking soda, cream of tartar and a "high temperature acid". When mixed with moisture, it releases gas at room temperature; when heated, the "high temperature acid" becomes active and more gas is released. Corn starch is added as a drying agent to prevent accidental activation. This is the most common baking powder sold in the Grocery stores.

Binders

Various types of flours are used to bind all the ingredients together. The Maida (All purpose flour) is the most common binder used in Indian cooking.

Binder/Puff Mix
In United States, Bisquick mix was developed to make Biscuits. Now there are many variations available and used for making different types of Pancakes. In Indian stores, most popular form of Bisquick is being sold to make Gulab Jamun under various brand names. You can make your own Bisquick.

Easy Bisquick