Fruits fall into two categories in answer to this question: Climateric which means that they do continue to ripen and nonclimateric, those that don’t ripen after picking. For those that ripen, the agent that makes that happen is a gaseous plant hormone called ethylene. We don’t usually think of a gas being a hormone but ethylene qualifies because, like other hormones, it’s effective in tiny amounts of less than 1 part per million.
Where does the gas come from?? The fruits themselves provide it . . . some more than others. The world class ethylene producers are apples, bananas and passion fruit (the champ). If you want to ripen fruit that can ripen after picking, put it in a paper bag with one of these 3, and in as little as 12 hours, you’ll have ripened fruit.
OK now a quiz: What fruits don’t ripen after picking?
We’ll post answers next week!
Hope to see you at my cooking demonstration at the Sonoma Marin Fair tonight!