Guava paste cooked to a firm, sweet consistency is a beloved Mexican confection. This family-friendly treat is a tropical, aromatic candy often paired with fresh cheese.
Wash and halve the guavas; scoop out the seeds carefully with a spoon to maximize pulp yield.
In a large saucepan, combine guava pulp and water. Bring to a gentle boil over medium heat, then simmer for 20 minutes until fruit softens, stirring occasionally.
Blend the softened guava and water mixture until smooth, then strain through a fine sieve to remove any remaining solids.
Return the guava purée to the saucepan. Add sugar and lemon juice. Cook over medium-high heat, stirring continuously to dissolve sugar and prevent burning.
Reduce the heat to medium-low and continue to cook, stirring often, until the mixture thickens and pulls away cleanly from the pan sides—about 45–60 minutes.
Once the paste becomes glossy and thick, spread it into a parchment-lined dish. Let cool to room temperature before slicing into portions.