Wash the guavas and remove any blemishes and the stem ends.

Chop the guavas and place the pieces into a heavy-bottomed pot.

Reserve ¼ cup of sugar. Add the remaining sugar to the chopped guavas and mix well.

Cover the pot with a lid and let it sit for 4 hours to draw out the guava juices for the syrup.

Mix the reserved ¼ cup of sugar with pectin and set aside.

After 4 hours, you should see about a cup of guava juice in the pot. Bring the guavas and their juices to a boil over medium heat, stirring often to dissolve the sugar.

Once boiling, reduce the heat to medium-low and cook for 10 minutes.

Turn off the heat and let the cooked guava cool slightly.

Pour the cooked guava and its juices into a food processor and puree.

Strain the guava pulp and juices through a metal mesh strainer into a separate pot. Press and rub the guava against the mesh to extract as much pulp and juice as possible. Ensure the strainer mesh is fine enough to keep out the seeds.

Add lime juice to the guava mixture and mix well.

Wash and peel the mangoes. Cut them into medium-sized chunks.

Puree the mangoes in a blender or food processor. Add the pureed mangoes to the pot with the guava-lime mixture and mix thoroughly.

Bring the mango-guava mixture to a boil over medium heat. Stir often to prevent it from burning.

Once the mixture starts boiling, reduce the heat to medium-low and cook for 15 minutes.

At the 15-minute mark, add the pectin-sugar mix to the jam. Stir well until dissolved.

Increase the heat to medium and cook for 5 more minutes.

Once the jam is ready, pour it into sterilized jars and process them according to your preferred canning method