Are we sure that figs cannot ripen more after being picked? I picked a few Jack's Black yesterday and one was left uneaten in the window sill. It sure looks darker today than yesterday. Of course I could be wrong, but it sure looks like it.

Maybe some varities do all trees arent the same

UCD has studied the use of ethylene gas without luck.

My son purchased a flat black mission figs shipped from California, and brought them home to me. We ate a few the first day and they were just ok. The next day we ate a few and they were distinctly sweeter and tastier, less insipid. Two days later they were even better. Oddly we noted those that had a  little surface mold tasted the best (after the mold was washed off.) These figs were still not as good as tree-ripened, but the point is that over time they did seem to ripen.

I also bought a flat of black missions from California last week and noticed the same thing. The longer they sat on the counter the sweeter.. juicier... figgier lol they tasted.

A couple years ago my niece gave me a fig from her parents tree (I believe it was a pingo de mel). It was barely even soft yet but she said just leave it on the counter and it will ripen. I was surprised that it actually did and even tasted pretty good. Obviously it would have been better picked ripe from the tree but it was still good.

I realize that some taste change may be the result of a some natural dehydration, thus a slight intensification of flavors. But the fig I am talking about got distinctly darker. Or at least it sure seemed that way to me.

Either way, it encourages me to let my figs sit on the window sill for a day or two before eating.