As far as I understand, the Dekopon has a LOT of acid, even when grown in hothouses and picked as mature as possible.
Then this acid this is removed by storing it and may be sold in Japan only if it has less as 1 % acid ...
Knowing the Japanese taste, I guess they make it as sweet as possible.

Nevertheless if having your own tree, you can get as much acid in it as you like ...

Well, the Dekopons I ate straight from the tree at UCR were not acidic at all. They were very sweet and quite good. Much better than the store-bought ones I have had. Worthy of a place in my backyard orchard. But I would not put them at the top for "all-time best mandarin". Close, though.

What I mean :

Only when getting fully ripe, the amount of sugar is rising.
So if someone wants more acidity he/she can pick it when it still has more acid and less sugar.

For me there cannot have too much sugar anyways ...
Even if it tastes like HONEY ...

Actually I thought that Dekopon was just a wee little too sweet if anything. - Millet

OK, but in Japan, they have tzroubles with TOO MUCH acidity ...
The original Dekopon breeded by the goverment was TOO SOUR and got dumped.
Only for a grower STOLE a twig and propagated it and found a way to reduce the acidity, it became a success.

Still only fruits with an acidity less than 1 % may be sold in Japan.

That would not be, if they are sugar sweet anyways ...

Millet, right off the tree they're not so sweet/insipid. They're actually much better and more complex than what I able to purchase at Whole Foods or one of the Asian markets here in San Diego county. I still don't think they match the Seedless Kishu, that was so outstanding and nothing came close to that mandarin while I was there (of course, timing is everything, and at that moment in time, it was the Seedless Kishu, even though they were techincally post-mature). And Sanguinello, who really understands the extreme food preferences that occur in Japan. I don't think they represent the rest of the world as far as taste. They tend to pursue things in extremes. The Dekopons grown here in California as exceptionally sweet and very good. No need to do anything tricky in storage for them, here. I will plant a Dekopon once they become available for home growers, it is worthy of a spot in my backyard orchard.

Barbara, I do not want to start a fight ... all what I say it that if you have a tree, then you can choose by youself by the time of picking what acid/sugar ratio you want.

Like for instance by picking the the Meyerii still a lil greenish, light yellow or dark yellow ...

Oh, no fight, Sanguinello. And yes, you can decide the level of acidity of any citrus by picking it at varying time around the maturity date. Just rebutting your comment that a Dekopon was acidic, as it isn't. However, someone from Japan, with their extreme preference for super-sweet citrus may disagree. For us here in the USA, the Dekopon is very sweet. And, my name is Patty (see my sig line).

Ouch !

Sorry for wrong name, still new here ...

Yes, I know the Japanese and my sense is same .. cannot be too sweet for me ..

I've just started seeing shiranui, which I gather is the generic name for Dekopon, for offer in N. Florida; apparently it was released in Florida within the last few weeks. So if you've been waiting, just keep your eyes open.

You can not take ANY citrus out of the state of FL.

Iwished I could get them too ... even if seeds or cuts or anything ...

here in europe it seams not to exist at all ...

like Meiwa Cumquat ...

No, you are not part of EU and possibily will not be soon, but of course you are european.

I just think you mix it up.
Meiwa is Fortunella crispifolia.
You probably mean Fortunella japonica.