You can substitute bouillon cubes in recipes with broth, stock, or a combination of herbs and spices for flavor.
Bouillon cubes will get sticky and stick to the paper they are wrapped in if they are not used within a certain time, so yes, they do go bad.
Cornstarch can be used as a substitute for arrowroot in recipes.
Parsley can be used as a substitute for cilantro in recipes.
Coriander or chili powder can be used as a substitute for cumin in recipes.
Paprika or turmeric can be used as a substitute for annatto powder in recipes.
Ground okra can be used as a substitute for file powder in recipes.
Vanilla extract can be used as a substitute for maple extract in recipes.
Butter or margarine can be used as a substitute for shortening in baking recipes.
Agar agar is a vegan gelatin substitute that can be used in recipes.
Stock cubes, also referred to as bouillon cubes are small, usually individually wrapped cubes of dehydrated stock. They are available made from vegetables and meats, contain a small portion of fat and are usually seasoned with salt and other seasonings. Mixed with liquid in a recipes, they dissolve into a broth.
Quinoa is a gluten-free substitute for farro that can be used in recipes.
Coriander is a spice similar to cumin and can be used as a substitute in recipes.