Although rum extract can be substituted for rum, there is a difference in the amount needed for dark and light rum. For recipes that require one tablespoon of dark rum, use 1/2 tablespoon of rum extract. For recipes that require one tablespoon of light rum, use 1/2 teaspoon of extract.
When buying rum extract, select products that are labeled "pure" or "natural" to ensure the product is pure extract. If the bottle is labeled "imitation," it is actually composed of artificial flavoring and does not have the same robust flavor as pure extract. If an extract does not contain the minimum amount of alcohol, it is considered a flavoring, not an extract.