Pectin/ˈpektɪn/ Definition 1 of 2Pro Tip 1/3Fruit Jelling Pectin is key for transforming fruit juices into jellies by heating. Strawberries alone won't jelly; you need to add pectin. Pro Tip 2/3High Pectin Sources Fruits like apples and citrus peels are rich in pectin, ideal for jams. Use apple peels as a natural pectin source for your jam. Pro Tip 3/3Commercial Pectin Pectin is often sold as a powder or liquid for home cooking uses. She bought liquid pectin to make her blueberry jam set properly.