I agree with all of this. Obviously you have some expertise.
Presumably astringency is a strategy that the persimmon uses to deter animals from eating the fruit before the seeds are viable. If that’s right, then there is some selection pressure – if animals eat the seeds, you fail to reproduce. But the plant also needs a mechanism for removing the astringency once the seeds are viable – if the animals don’t eat the fruit, they won’t spread. So better yet, there’d be 2-3 mechanisms.
Let’s imagine that the primordial persimmon ancestor evolved two mechanisms for removing astringency. In other words, the “how so” was multi-faceted from the outset. Then maybe, as D. virginiana and D. Kaki evolved, each came to depend more on different mechanisms. In other words, a different “how so” is predominant in the different species.
It might be interesting to know how other persimmon species, such as D. lotus, respond to ethanol and CO2.
I’ve not tried cultivars outside of Hachiya and Fuyu but below is a photo of dehydrated astringent Hachiya slices.
As detailed in this thread, they were store-bought, still hard/astringent, peeled and sliced, and placed into a food dehydrator at 140°F for 17 or 18 hours. They come out very sweet and delicious. You may wish to try it with other varieties.
This year I had two astringent Kasandras to test. Since I had no idea about its potential and I picked them right after the first hard frost when the tree defoliated, I thought it was time to test taste. My wife and I got a strong pucker although the sweetness was very nice. So I threw the other one in a plastic bag where I toss e in my banana peels that week. After a week we tested the second one and we’re pleasantly impressed by no pucker factor. So before you invest in expensive equipment, try eating some bananas! You might be ok with the results!
Dennis
Kent, wa
@DennisD – Based on my experience here, a not-completely-ripe Kasandra can be quite astringent. And cold temps including frost do nothing to accelerate ripening or reduce astringency. On the other hand, if you have to pick before full ripeness, bananas will encourage ripening, as you note. Combine bananas with ethanol and you get both ripe and non-astringent.
Hi JRD,
In my very limited experience with Kasandra, the banana peels removed all astringency after 5 days in the sealed bag. But with such a small sample size I could not test more this year since I had only 2. If I get more next year, how do you use alcohol? Are you using an open dish in a sealed bag? When we tested the first one right after picking, the sweetness was impressive, so it was already as ripe as I would desire, just astringent. I would like to try your process for using alcohol next year as I likely will have several ripe but astringent Kaki varieties.
Thanks
Dennis
Kent, wa
Normal ripening will usually remove astringency, but for some reason some fruits are slow or resistant. For Asian persimmons and some hybrids (I can only vouch for Kasandra and JT-02), exposing the fruits to ethanol vapor accelerates the loss of astringency without affecting ripeness. CO2 does the same.
I’ve used alcohol in two ways. In both cases, I put the fruit in a plastic bin. In one method, I include a cup of 80 proof vodka. In the other method, I spray the fruit directly. Then I close the bin so that the fruit can be exposed to ethanol vapor.
Last year, using the “cup of vodka” method on Kasandra, it took about a week to reliably remove astringency but the fruit were nearly ripe when I started. This year, it took about 10 days including a banana but the fruit were far from ripe when I started.
I’ve been trying the same approach – banana with a cup of vodka – with JT-02. These fruits were much less ripe than Kasandra when picked. It’s been roughly 2 1/2 weeks since I picked them. Probably 2/3 have ripened. If they are totally soft, they are non-astringent. But if they are still somewhat hard (usually around the calyx) then they will be astringent. I was thinking that ethanol helped with JT-02 but this pattern suggests to me that ethanol may not be having much effect; rather, loss of astringency seems to be driven by ripening, which is assisted by the bananas. I’ll need more trials to be sure.
