The modern kitchen requires us to think differently about the food we eat. Most of these ingredients are the same foods you have always used: fresh produce, dried beans, grains, fruits, meats, dairy, oils, sugars, salts, etc. However, some staples in the modern kitchen may be unfamiliar--and perhaps a little frightening to people who have not used them before. Some of these may be things you've seen only seen on food labels. Due to a generalized mistrust of the processed food industry, you might be a little worried about what these are, where they come from, and how they might affect your health. I respect that sentiment. As we go forward, I will do my best to explain where each ingredient comes from, what it can be used for, and the advantages of the modern version over more familiar cooking supplies. Today, we'll just talk about three different categories of ingredients: thickeners, gelling agents, and emulsifiers.
Thickeners give body to a sauce and slow down the flow of fluids. When you make a simple pan gravy, you take the drippings from the meat and then whisk in a little corn starch. After boiling, this produces a much thicker sauce. However, the starch molecules have a tendency to hold back flavor. A simple substitution of xanthan gum or Wondra accomplishes the same task with a lower quantity of thickener. This allows the flavor of the sauce to shine through without any starchy taste or texture.
Familiar: corn starch, flour
Gelling agents include gelatin and pectin, the critical ingredients in Jello and fruit jam. These ingredients are fantastic, but each has limitations. For example, gelatin-based dishes melt into thin liquids at body temperature, while agar-based gels can form similar structures (and even thick liquid gels) at much higher temperatures. Agar is not animal-based and therefore suitable for vegetarians and vegans. Carageenan is an ingredient I have not yet used, but it is a commonly used in commercial chocolate milk to make a thick, pourable gel.
Familiar: gelatin, pectin
Oil and water don't typically mix, and emulsifiers allow these ingredients to come together into a smooth, stable mixture. The most common emulsifier is called leciithin, and it is formed from the cell membranes of many living organisms. Lecithin is found in abundance in egg yolks, which makes it the critical component of mayonnaise. Purified lecithin is usually made from soy beans, but it can be used in much smaller quantities than an egg yolk and has zero risk of curdling with heat. Sodium citrate is a salt of citric acid, and it raises the pH of sauces and binds calcium. In milk-based sauces, calcium binding causes milk proteins to better interact with both water and fat, allowing you to make unbelievably smooth cheese sauces.
Familiar: egg yolk, roux (flour and butter)
Are you skeptical that you won't use any of these? Wait until you learn how to make the ultimate cheese sauce. You may just change your mind!