I’m particularly curious about alcohol vapor treatment or other methods that would remove the astringency from astringent-type persimmons without substantially altering the texture. From what I’ve read it’s apparently possible to eat a still-firm astringent type persimmon without the astringency. Has anyone tried it? Anyone know about it? Are there any other methods (besides drying, which I’ve heard a lot about, besides eating the incredibly delicious dried fruit – probably the best dried fruit I’ve ever tasted) that you’ve tried for removing astringency from astringent type Asian persimmons? If so, what did you think of the results? Freezing apparently works, too, but I imagine the texture then goes very soft.
What methods have you used to remove astringency from Asian persimmons besides drying?
I’ve done that almost every year of my life since age 7. Two factors are important:
- Knowing when they are ripe enough to pick. Firm yes, but ripe. This is learned by trial and error.
- Cultivar. Many cultivars are astringent by nature and there’s no use fighting it. I was fortunate to grow up near a 40’ high 50’ wide Fuyu that was planted circa 1900. I have also gone to the persimmon tastings at Wolfskill several times. For my climate I prefer Izu.
I don’t like drying to remove astringency. All that helps is the cutting up of the fruit. The finished dried product isn’t nearly as good as drying soft ripe fruit. By letting it ripen first the starch is converted to sugars.
I also don’t like freezing. The fruit isn’t as good as allowing a natural ripening.
I don’t think you are going to get good sweet fruit unless you accept the soft texture. This refers to the true astringent types not Fuyu.
I’ve removed astringency by freezing… but only because the fruit was not mature enough when picked. If the fruit is not mature enough when picked, it will not ripen well. Many astringents can be picked and ripened naturally when they have some color, but my experience has been that this is not the case for all astringents.
Astringents ripened by freezing are still good, but not as good as those naturally ripened.
Fruitnut, when you say “all that helps is the cutting up of the fruit,” do you mean picking before completely jelly-ripe helps to cut up the fruit? If I fully ripened the fruit before drying, I wouldn’t even know how to go about drying it at all? Do you do it like fruit leather on parchment paper? I have a Korean friend that peeled astringent type persimmons while still firm enough to peel and dried them by hanging outside under an eave in the sun. Those dried persimmons were so delectable it’s hard to imagine they could get any better, and I don’t think I’d even want them any sweeter, not for just straight eating anyways.
I’m not at all opposed to the soft texture, but I’ve also enjoyed the non-astringent persimmons I’ve eaten, based on my limited experience so far especially at the stage when they’re just past crunchy, about like a peach that’s still firm enough to hold together well and slice neatly. My understanding is that astringent persimmons can be eaten at a similar stage by alcohol vapor treatment, and that some of them may taste even better than the naturally non-astringent types. I think someone posted a link to a fairly lengthy academic paper on this forum within the last year about persimmons in Japan, and that paper – I don’t know where to find it again – seemed to suggest that a large percentage of the fresh persimmons eaten in Japan are alcohol vapor treated astringent-type persimmons.
And even if alcohol treated astringent persimmons weren’t any better (or different in a good/interesting way) than naturally non-astringent varieties, astringent varieties would still, it seems, provide advantages when it comes to wildlife taking the fruit: it could be easier to go to the effort of removing the astringency if the astringency would protect the fruit from wildlife than to grow naturally non-astringent fruit and have to find other ways to protect the fruit from wildlife. So those are more or less the reasons I’m interested.
Here are a couple links that a search engine turned up that I found before starting this thread and thought were somewhat interesting:
I’m still able to slice mine up after they soften. Just don’t let them get too soft. If cut up at the hard orange ripe stage the dried product has a much less appealing color and less flavor. Mine dried with no treatment, cut up, soft ripe, have a beautiful translucent color dried just like they do before drying.
I’ve tried the alcohol but didn’t have much luck. Maybe not the right techniques or alcohol. I’m not a drinker.
Putting them in a bag with a ripe apple has potential. That can speed ripening to get a batch ripe all at once for drying.
In the right climate drying like your friend sounds good but peeling doesn’t appeal at all. I’m very happy with my dried product.
A persimmon discussion list just drew my attention to this very interesting article/post:
I use CO2 gas just like them professionals. Then you can eat the hard crunchy fruit or let it soften.
I learned another alcohol curing tip passed down through my Japanese American family- we put persimmons in a bucket and prop them upright by crumpled newspapers or just stack them propped against each other so their caps are on top. Then we fill the caps with some type of alcohol using a dropper or baby-medicine-syringe. My grandmother used gin, I’ve used vodka and just last week used some schnapps. Only a small amount is needed to fit in each cap. Layer the persimmons in the bucket or any other container and put a lid on it and store it somewhere cool. It doesn’t have to be a secure airtight lid. I keep mine in my cellar and actually have some mismatched lid that is just a loose cover. Refill the caps again after a couple days, and they will be ready to eat in about a week. I usually wait 8-10 days just to make sure, and I refill the caps two or three times during that time. I pick my hachiyas while they are still very firm and they stay firm, although a couple usually soften. I don’t detect any alcohol when eating them, and the type of alcohol used doesn’t alter the flavor.
Has anyone tried the soaking in water method? Supposedly it just takes a couple days. I may have to try it out when I start getting persimmons in a few years.
First saw it in this video. Read about it a few other places, too.
@Tamichan – Thanks for this idea – I’m going to try it on my astringent American, Prok. Searching the internet I found an article with pictures that illustrate exactly what you describe. Some takeaways from my reading of this article and others:
Alcohol vapor facilitates the entry of ethylene into the fruit. Only small amounts of alcohol are required.
It’s probably best to use a tasteless, odorless alcohol, such as vodka.
The process is not helped by added heat. Room temperature is fine.
The process can be accelerated by supplemental ethylene from a ripening apple or banana.
I’m especially interested in knowing whether alcohol plus ethylene would remove astringency from persimmon flesh that has already been processed into a puree. I’m imagining a 2" layer of puree in a large tray. I’m guessing that the relevant chemistry doesn’t stop just because the fruit has been ground. I also imagine that alcohol vapor would suppress fermentation long enough – but that’s TBD.
Edit: persimmons harvest , and elimination of its astringency | UBC Botanical Garden Forums
And then there’s this. Apparently I can skip the whole CO2 / alcohol pre-treatment by mixing some soy protein into the persimmon paste.
Fascinating! A little soy milk is all you need.
Right. Now I just need to get info on the required amount.
I’ve also used soy and whey protein as a nutritional supplement. The stuff I use is flavored, but I could easily find some unflavored. The stuff keeps forever and I won’t need much.
Botanist wanted, familiarity with persimmons preferred!
I’m trying to read the available scientific literature on persimmon astringency. I’ve come to some tentative conclusions. I’d love for some actual plant scientist to check my work.
Ethylene, the so-called ripening hormone, has a very modest role in the final ripening of persimmon fruits. It may be important for initiating the process, but it is not important at the end.
Final ripening – and removal of astringency – is driven by acetaldehyde, which is produced enzymatically from endogenous ethanol.
Production of ethanol and acetaldehyde is enhanced during anaerobic respiration. Strategies for reducing astringency, such as CO2 and alcohol vapor, work by encouraging anerobic respiration. Maybe alcohol vapor also works by raising the amount of ethanol in the fruit, which would then increase acetaldehyde.
Acetaldehyde reduces astringency by binding with the tannins in the persimmon fruit, creating insoluble products.
See for example:
<< Here, we propose that the removal of astrigency in persimmon fruit by carbon dioxide gas or immersion in warm water consists of at least 2 processes. In the first process, the fruits in a carbon dioxide atmosphere or immersion in warm water produce a sufficient amount of acetaldehyde via glycolysis, enzymatic reactions. Fruit treated by ethanol vapor also accumulates a high level of acetaldehyde, since the absorbed ethanol is oxidized easily by alcohol dehydrogenase inside the fruit. In the second process, soluble kakitannin in the vacuole reacts with the acetaldehyde and transforms into an insoluble and non-astringent form, may be gel, through a non-enzymatic process. >>
My mislabeled persimmon, probably Jiro, seems to have some lingering astringency, even though the fruit are fully orange. Same deal with my coworkers “Fuyu” which I believe are the same Jiro as mine based on shape and ripening time.
Some have been on the counter for 2 or 3 weeks and have gotten more orange. I’ve got a few in a box with an apple. Don’t have any bananas or alcohol. I do have a Sodastream. Maybe I’ll give my quick and dirty CO2 in a bag a go.
But Jiro / Fuyu are not supposed to be astringent at all. Isn’t it more likely that your mislabeled tree is an astringent variety?
Hey jrd51, did you ever try the soy treatment? I have a bunch of persimmon paste with some lingering astringency and I’m hoping to make it edible.
Ultimately though my goal is making persimmon wine. I wonder if the alcohol production will handle the astringency on its own, thus maybe I don’t need to treat the paste before fermentation.
Fwiw, I don’t believe that ethanol reacts directly with the tannins. You need to remove the astringency using the biology of the fruit. In any case, vodka mixed with astringent (American) persimmon paste yields astringent persimmon paste. That I did try.
I only have experience with wild american so far…
I picked several recently off a tree… that had started to soften a little.
I put them on the kitchen counter under a glass bowl… for 7 days… then tried one and absolutely no astringency… and awesome flavor.
For small batches that works for me.