All Purpose Flour
This is a must for every kitchen. Flour is the main ingredient for bread, which is a staple food for most parts of the world. All purpose flour has an intermediate gluten level which makes it so versatile (high gluten bread flour is tougher and holds its shape, while the lowest gluten cake flour develops a much finer texture).Not only is flour the essential ingredient for baking, but it is also useful for preparing and thickening sauces and gravies.
Self Rising Flour
Similar to All Purpose Flour, but is premixed with leavening agents and salt. Self-rising flour can be used as a substitute for All Purpose Flour, but it is necessary to remember to remove the leavening agents (baking soda and/or powder) and salt from the recipe. A typical cup of self-rising flour contains ~1 tsp baking powder and 1/2 tsp of salt. Since it is flour, it can also be used as a thickening agent for sauces and gravies.
Cornstarch is also known as corn flour and is produced from the starch of maize. Similar to flour, cornstarch is used to thicken sauces and soups. Cornstarch provides a more translucent product than flour, so it is also used to thicken pie fillings and puddings. Cornstarch also has twice the thickening power of flour.
Different from corn starch, cornmeal is flour that has been ground from dried corn. An everyday staple in the cooking of many cuisines (polenta, hush puppies, corn bread or muffins), it is also useful as a release agent (to make fresh pizza dough slide off the peel and onto the stone).
Baking Soda and Baking Powder
Both baking soda and baking powder are leavening agents which are what give foods (bread and cakes) their light airy texture. Baking soda is a chemical lever (sodium bicarbonate) which reacts in the presence of both moisture (the liquid components of a recipe) and heat (in the oven). Baking powders are double acting, being a combination of baking soda and commonly, cream of tarter. The cream of tarter reacts at room temperature making batters or doughs rise as soon as they are prepared (pancakes and muffins), while the baking soda reacts at elevated temperatures (during baking).
Yeast (active dry)
Yeasts are unicellular microorganisms that have been used as the levening agent and for the fermentation of alcohol for thousands of years. Yeasts even through the process of fermentation, when the microbes consume sugars generating carbon dioxide (which create small gas pockets causing doughs to rise) and alcohol (which burns off during cooking). The different flavors of beers and wines are generated by the types of sugars that are consumed during the fermentation process (other flavoring ingredients may also be added).
Unsweetened Cocoa Powder
Cocoa powder is the non-fat portion of chocolate. Widely used as a flavoring for cakes, cookies, and brownies. Comes as either natural or Dutch-processed, depending upon the process used to separate the cocoa powder from the chocolate. Natural cocoa powder is slightly acidic which allows it to react with baking soda in recipes. Dutch processed cocoa powder has been neutralized and should be used in recipes calling for baking powder. The neutralization process gives the cocoa of the Netherlands a milder flavor.Naturally processed cocoa powder has a more intense flavor.
Unsweetened & Semisweet Chocolate
Whether purchased in blocks, bars, chunks, or chips, chocolate is one of the most common flavors in the world. It is indispensable as a flavoring in baking snacks (cookies and puddings), and desserts (ice cream, cakes, pies). Unsweetened chocolate is pure chocolate with an intense, dark, chocolate flavor (also known as bitter chocolate). Semi-sweet chocolate is a combination of unsweetened chocolate and sugar.