Cut guavas in half and scoop out the seeds.

Soak the seeds in 1 cup of water.

Place the guavas in a saucepan with the remaining 1/2 cup water.

Bring to a boil, then reduce heat to a simmer.

Cook until the guavas are very soft, stirring frequently to prevent scorching.

Strain the water from the soaked seeds and add it to the cooked guavas.

Discard the seeds.

Grind the guavas through a food mill to create a pulp.

Measure the amount of guava pulp.

Add an equal amount of sugar to the pulp.

Mix well and place in a large, heavy saucepan over low heat.

Cook, stirring constantly with a wooden spoon, until the mixture is thick and a small amount tested on an ice cube can be lifted off in one piece (jelly-like consistency).

Remove from heat and beat with a wooden spoon for 10 minutes, or until the mixture forms a heavy paste.

Pour the paste into a loaf pan or square casserole pan lined with wax paper.

Set in a cool place for 24 hours to set.

To store, remove the paste from the pan and wrap it securely in foil.

For a drier consistency, place the cooked paste on wax paper on a wooden board, cover with cheesecloth, and set in the sun for two days, turning occasionally.