# Method:
01 - Wash guavas thoroughly under running water. Cut them into quarters, keeping skins and seeds intact for natural pectin extraction.
02 - Place guava quarters in a large saucepan, add 4 cups water, and bring to a boil over medium heat. Reduce heat and simmer for 30 minutes until fruit becomes very soft.
03 - Line a large strainer with double-layered cheesecloth and position over a bowl. Pour cooked fruit and liquid into strainer. Allow juice to drip undisturbed for at least 2 hours or overnight without pressing or squeezing to maintain clarity.
04 - Measure extracted juice and pour into a clean saucepan. For each cup of juice, add 1 cup granulated sugar and 2 tablespoons lemon juice. Stir well to combine.
05 - Bring mixture to a boil over high heat, stirring constantly to ensure sugar dissolves completely and mixture incorporates evenly.
06 - Boil rapidly for 15 to 20 minutes while monitoring temperature with a candy thermometer. Continue until mixture reaches 220°F. Skim off any foam that rises to the surface.
07 - Place a small spoonful of jelly on a cold plate and allow it to cool slightly. Push with your finger; if it wrinkles, the jelly has reached proper gel stage.
08 - Pour hot jelly into sterilized jars, leaving 1/4-inch headspace from the rim. Seal jars immediately with sterilized lids.
09 - Allow jars to cool completely at room temperature before transferring to a cool, dark storage location.