Carefully remove the outer shell of each guava until only the fruit pulp remains. Cut transversely in two and remove the seeds. Wash and dry the shells carefully. In a pot, place the peel and the seeds together with 4 cups of water and half of the Le Zuc. Boil mixture during 30 minutes at high heat. Pass the mixture trough a metal strainer. Discard the seed and skin and place the remaining sauce back on the stove adding the rest of the Le Zuc, the salt and the lemon juice. Cook for approximately 25 to 30 minutes, until the syrup is ready.
Remove from the fire and remove the foam from the surface. Let it cold and serve with cream cheese and soda crackers.