Guavas (Psidium guajava L.) are one of the better-known tropical fruits, grown and consumed for their sweet flesh, which varies in flavor and aroma. Because of this, judging ripeness may take a little practice, but isn’t difficult. Knowing when guava is ripe will also help you harvest and store it properly. Guavas are considered invasive in some locations.
Guava is native to parts of Central and South America, but will now grow in tropical zones around the world. It is hardy in U.S. Department of Agriculture plant hardiness zones 10 and 11, though it may grow as far north as USDA zone 9b. There are several varieties. Pink- and red-fleshed types such as “Blitch” and “Patillo” are eaten when soft and ripe, while white-fleshed types like “Lotus” and “Webber” are usually eaten before they are ripe, while still crispy.
Depending on what you want to do with your guava and how you like to eat it, you can pick it at different times. For white types that taste best when crispy and under-ripe, pick when skins are still very green. This is called the mature-ripe stage, and fruits change from dark green to a lighter green when they are ready for picking. For storage of the type that is eaten when ripe and fleshy, pick when the skin is yellow but still firm. For immediate consumption, wait until skins are fully yellow and quite soft.
You can also judge the ripeness of guavas based on aroma. They generally have a musky scent, and it ranges from sweet, penetrating and highly acidic to mild and gentle. Although the smell itself varies, you can judge ripeness based on the fact that there is a strong smell. Under-ripe guavas will not give off nearly as much of a scent.
Harvesting and Storage
Pick guavas gently, especially when they are fully ripe. They bruise easily, and store badly once they are already bruised. For immediate consumption, you don’t need to be quite as careful. To keep guavas for a while, you can refrigerate ripe specimens and use within two days. You can also pick them just before they are ripe and allow them to ripen at room temperature, which may diminish the chances of bruising. You can also freeze them by cutting them in half, skinning them and scooping out the seeds before packing them in quart jars and covering them with unheated syrup -- 2 parts sugar to 1 part water. Be careful around children when using glass jars.