To know when a feijoa is ripe, you should look for the following signs:
Color: A ripe feijoa will have a green hue, but not overly bright. The skin should be smooth and free from excessive blemishes or bruising. As the fruit matures, the green may become slightly duller, which is an indicator of ripeness.
Texture: A ripe feijoa will exhibit a slight softness to touch, similar to that of a ripe avocado, giving in gently under pressure. When you press near the stem, the fruit should give slightly, indicating that it is at the peak of its ripeness and will detach easily if still on the tree.
Aroma: The aroma of a ripe feijoa is a reliable guide. A fragrant, sweet smell, especially around the stem end, suggests the fruit is ripe and ready to consume.
Additionally, feijoas fall off the tree when ripe, so if you find one on the ground, it is likely ready to eat. If the fruit is still rock hard, put it in a bowl on your table for a day or two, as it will soften and become slightly squeezy.
When the feijoa is ripe, it will have a bit of give when you squeeze it, not squishy, but with a slight softness. If it’s still rock hard, it may require additional time to ripen.
Citations:
[1] https://discover.texasrealfood.com/the-art-of-savoring/how-do-you-eat-a-feijoa
[2] https://www.milkwood.net/2018/05/10/all-about-feijoas-growing-harvesting-recipes/
[3] https://growingfruit.org/t/have-my-first-feijoa-is-it-ready-to-eat/12889
[4] http://fruitexplorer.blogspot.com/2014/11/the-fruit-explorer-encounters-feijoa.html?m=1
[5] https://flavorsofbogota.com/how-to-eat-feijoa/
[6] https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=8678
[7] https://tuigarden.co.nz/inspiration-hub/ideas-and-inspiration/fantastic-feijoas-all-you-need-to-know/
[8] https://trees.stanford.edu/ENCYC/FEIJOAsel.htm
[9] https://www.houzz.com/discussions/6016407/sf-bay-area-feijoas-are-they-ripening-now
[10] https://www.youtube.com/watch?v=ATnpsrkwkgA
[11] https://agriculture.gov.capital/what-are-the-signs-that-feijoa-fruits-are-ripe-and-ready-to-be-harvested/
[12] https://ayeshahaq.com/2009/04/26/fruit-of-the-week-feijoa/
[13] https://www.youtube.com/watch?v=cFnFKKoRaC0