I’m still waiting on my trees to fruit so I can start testing, but in short I’ve heard of success with some hybrids but not others (I don’t remember which off the top of my head), and no successes with D. virginiana. I’m convinced that it’s possible, as it’s likely the astringency differs in quantity not in type, so should respond to the same types of treatments. My understanding is that even among kaki, there is varying responsiveness to treatment.
The approach that I find most promising is submerging in a hot water bath (60c) for an hour. I’ll have to dig up the paper again, but the researchers found that kaki fruit responded really well to this treatment, but if left too long, the astringency would come back. The fact that the astringency comes back makes me think one of two things is going on with hybrids and virginiana:
- The astringency is lower in hybrids and virginiana, so we may be overdoing it
OR - The astringency is so high in virginiana that it doesn’t fully dissipate before the “coming back” mechanism kicks in
2a. Astringency is so high that maybe they need more time in ethanol or CO2, or it just takes so long that the fruit has naturally softened anyway by the time it’s done.
Again, this is all speculation. I know @jrd51 has chipped away at some aspects of this, and I’ve seen no successes with virginiana yet*. However, I do believe there are a few variations that haven’t been tried yet. I’d like to explore these more thoroughly before ruling out the possibility. It may be as simple as certain varieties of virginiana work and some don’t.
*I did see one video where a guy was putting some virginiana in a container with some vodka to remove astringency. The fruit were ripe enough to shake from the tree, so I’m not convinced the ethanol actually did anything… I’ll add a link to the video if I can find it again.
Edit:
Here’s the video. I was wrong, he is picking the fruit hard. However, he doesn’t address whether the fruit is still hard after the ethanol treatment, nor does he compare to fruit that have just been left out at the same time. So, it’s an intriguing anecdote, but not airtight by any means.
