Rinse your guavas under cool running water and pat them dry with a clean towel. Cut each guava in half lengthwise, then scoop out the flesh into your blender, discarding the skin and leaving behind the harder seed pods if desired (though soft seeds blend in fine).

Pour the cold water into the blender with the guava flesh. Using cold water helps preserve the juice's bright color and keeps oxidation to a minimum.

Blend on high speed for 60 to 90 seconds until the mixture becomes completely smooth and uniform. Stop and scrape down the sides if you need to, then blend again briefly to catch any chunks hiding near the blade.

Pour the blended mixture through a fine-mesh strainer set over a large bowl, pressing gently with the back of a spoon to extract all the liquid. This step removes the hard seed centers and any remaining pulp, giving you that silky juice texture instead of a thick smoothie.

Squeeze fresh lime juice directly into the strained juice and stir well. The acidity of lime prevents browning and adds a subtle complexity that makes the guava flavor sing rather than fall flat.

Take a sip and decide if you want added sweetness. Stir in honey or agave if your guavas tasted more tart than sweet, adding it a half tablespoon at a time and stirring until dissolved.

Add a tiny pinch of salt and stir thoroughly, letting it dissolve completely into the juice. Salt sounds odd in juice, but it genuinely rounds out the fruit's flavor by suppressing any lingering bitterness.

Pour the juice into a pitcher and refrigerate for at least 30 minutes before serving, or serve immediately over ice if you're impatient. The juice tastes best cold, and the flavors actually meld together nicely as it sits briefly in the refrigerator.