Occasionally recipes will call for port in the ingredients, usually something that is a very heavy dish such as a roast beef-based dish. This is especially true in older recipes that may have been passed down through the family.
Today, not many families tend to have port in their liquor cabinets or pantry. Or you might not want to spend the money to buy a whole bottle of the port when you just need a small amount of it for a recipe.
There are a few different things you can use to substitute for port in a recipe.
You can combine cranberry juice with a small amount of lemon juice as the substitute.
The second one might require a trip to the grocery store, but you can combine concord grape juice as well as a bit of lime zest to substitute for port.