I've seen this Q&A
What can I do to help my avocados ripen?
And this one
Will avocado stay fresh longer if stored in the refrigerator?
and this one
What can I do to help my avocados ripen?
but none of them answers my question which is:
I have an avocado I cut open but it's not ripe yet. Being that it's already cut what if any are my options? For the moment I poured some lemon juice on the exposed parts, put them in a container and put them in the refrigerator but I kind of get the impression they'll never get ripe in there and I should just throw them away. Being already cut it doesn't seem like I can leave them out of the refrigerator in a paper bag.
Is there any way to rescue these already cut but unripe avocados?
Best Answer
If you don't want to use the unripened avocado right away, according to this site
Another user suggests to use vitamin C powder instead, as her experiments show the vinegar would darken the avocado.
Ironically enough, there's a solution to ripen the avocado (almost) instantly if you want to use it right away. This link talks about "instantly" ripening a foil wrapped avocado by baking it in an oven preheated to 95°C/200°F oven. Cooking time can start as low as 10 minutes. Keep checking every 10 minutes until it's soft enough for your use. After it's been in the oven, let cool and unwrap.
Note: that the taste and texture would be changed after thus heating the avocado, but it should be usable right away after baking.
There's also uses for the unripened avocado seen here