Pectin is a type of sugar that occurs naturally in some fruits such as apples and berries. It is a type of polysaccharide and it is commonly used as a thickening agent in jams. Some pie recipes call for high-pectin fruits that will naturally thicken the filling. However, there are many fruit pie recipes that call for fruits that are lower in pectin, so you may need to add a thickener.
Determine if the fruit you'll be using has a high amount of naturally occurring pectin. If this is the case, you will not need to add extra pectin to your recipe.
Test the fruit for pectin if you are not certain of its level. To do this, mix 1 tbsp. rubbing alcohol with 1 tsp. of fruit that has been cooked and cooled. If it forms a solid, jellylike lump, it is high in pectin. If it forms a couple of medium-sized pieces, it has an average amount of pectin. If it only forms small, jellylike particles, it is low in pectin.
Set up the mixing bowl and prepare the ingredients that your recipe calls for.
Measure out the amount of pectin you'll need. Follow the directions on the pectin box for the type of fruit that you are using. Getting the exact amount right can take practice since the sugar in fruits varies.
Mix the ingredients according to the recipe. If you will be cooking the filling on the stovetop before adding it to the crust, add the pectin directly to the filling. If you will be mixing the ingredients and then baking, dissolve the pectin first.
Follow the rest of the recipe and bake accordingly. Allow the pie to cool before sampling it.