It sounds like you're describing mangoes picked immature green (not mature green). A mango picked mature green takes 4 - 7 days to ripen, and there should be no discernible difference in acidity nor brix. If you pick immature green (ie, to where it takes 2+ weeks to ripen), then you will note more of an acid component and lower brix.
It does take a bit of practice to pick them mature green though. I still get it wrong more times than I care to admit. Ms Wenzel of Truly Tropical has many great videos where she details the characteristics she looks for when picking a mango -- on a cultivar by cultivar basis, as it does vary.
I use 4 main signals to determine mature green stage, in combination:
- Time of year (cultivar dependent). For example, LZ can generally be picked starting sometime in July here in FL.
- A color change from dark green to lighter green (a yellowing of the skin)
- Firmness. A mature green fruit will have just a tiny bit of give when squeezed very hard (vs rock hard)
- Size + shape (eg, shoulder fill -- largely cultivar dependent)
There is a difference in texture (ie, chalkiness) between a tree ripened mango and one ripened indoors. The former can be more watery / gelatinous, but I believe this is more a factor of potassium to calcium levels in the fruit (you can create the same texture by upping potassium and holding back on calcium).
With OS, you sort of have 2 options: pick mature green and get a delectable mango, or allow to tree ripen and eat a gelatinous ball of goop. Is it extremely susceptible to internal breakdown (even Walter complained about that). On good years, some of the fruit turn out OK. On bad years, most of the fruit get soft nose or jelly seed.
It's actually backwards. It's common knowledge that one way to mitigate internal breakdown is to pick mature green. It's even mentioned in IFAS' "Mango Growing in the Home Landscape" article (scroll down to "Internal Breakdown" http://edis.ifas.ufl.edu/mg216).
I know this from experience -- having picked mangoes at various stages over the past few harvest seasons. Flavor is often enhanced by picking mature green.
OS is one mango that is very prone to internal breakdown disorders and should be picked mature green.
This picking green $hit is the cause of a lot of the tasting issues.
Sirry, I disagree 100%. Any mango picked green will hae some level of acidity that one picked tree ripe wont have. I have been picking these for many years at Walter's and have had the ability to try them at many stages. To me and most who purchase from him (and those I have personally sold to, tree ripe rules.
I have eaten a ton of mangoes picked mature green from ZHPP, totally different experience and not usually in a good way. If you look backbat many reciews on Gardenweb of the newer varieties that were numbers before they were named, the fruit were not given high praise. The Sweet Tart and Pineapple Pleasure, to name a couole, were horrid picked green. Pina Colada could have been sold to the school board as teacher's chalk.
Bottom line, to each their own...BUT...mist that I have sold to and shared with very much prefer tree ripe. These are mangoes to be eaten niw, not shipped commercially.