Smell before you select. A perfectly ripe guava is one that you can smell without even putting it to your nose. It should smell sweet and slightly musky. If you have eaten a guava before, look for guavas that smell like they taste.ash your guavas. You should wash the entire guava, as the rinds are actually edible. Rinse the fruit with cold water in an effort to quell any bacterial growth. Pat your guavas dry with paper towels. 2. Place your guava on a cutting board. Using a knife, slice your guava in half.