Ingredients are very important for any recipe, and you can’t change them without consequences. Each ingredient plays an important role in the recipe. But, sometimes you just simply don’t have everything that the recipe calls for.
Luckily, in many cases, substituting one ingredient for another is not the end of the world.
Many foods can be replaced with suitable substitutes, with no actual affect on the meal.
Sometimes the ingredient you are missing is simply a combination of two or more base ingredients. Brown sugar, for example, is just sugar and molasses.
The following handy infographic is meant primarily for baking and cooking. So, use your best judgement when deciding what to substitute: pumpkin does not make a good omelette.
It’s important to look at the physics behind each of the foods in the image. Often, one type of food is just another, but in a different state. Milk, half-and-half cream, and butter are all basically milk with different levels of fat. Dark corn syrup is just light corn syrup with added molasses, so you can just add the molasses yourself.
Other times, the food may be unrelated, but perform similarly. There is no way that pumpkins and eggs are related, but, in baking, they can perform the same binding functions. Cracker crumbs may be chemically different than dry bread crumbs, but if you are using them primarily for the structure, it doesn’t matter.