I know this subject as been hashed to death but I would like to present some info I just learned and to ask one additional question.

I currently soak and dehydrate our nuts for several reasons: to remove phytates, to remove bitterness, and to season them without sugar, msg, nutritional yeast and other non-compliant ingredients.  It's also the only way I can get DH to eat walnuts.  Neither of us has any trouble digesting them whether soaked or not.

How I currently prepare our nuts:

First, I soak them covered in water with a pinch of Himalayan sea salt. I use the water from my Reverse Osmosis filter as I don't want any of the chemicals and contaminants in tap water leaching into my nuts.  I soak walnuts for 2-3 days, almonds for 24 hours, and pumpkin for about 12.

Regardless of how long I soak the nuts, I change the water every 8 hours, rinse thoroughly (with tap water), and add a little salt each time.  

I then dry the nuts in our oven set to 118f.  Before drying, I leave the salt-water clinging to them after draining and dust them with cayenne and/or garlic powder and/or cumin.  I roast until I no longer detect any moisture in the nut.

If you don't dry them thoroughly before returning them to their original container, they will mold.  I learned this the hard way.  Now, I dry them for as long as I soak them.  If I soak for 2 days, I dry for 2 days.  Pumpkin seeds seem to take longer to dry -- a 4 hour soak may require 2 days in the oven.  

This site, http://www.yogitrition.com/soaking-grains-beans-nuts-and-seeds-101/ , recommends soaking walnuts in food-grade hydrogen peroxide first, to remove any mold.  I have not done that yet but may try it and see how they taste.  That site also lists the optimum length and temperature for soaking most nuts, grains, and beans.

Regarding whether to soak and/or roast nuts:

The reason we are advised to soak nuts is to remove phytic acid which strongly inhibits mineral absorption in adults and interferes with enzymes we need to digest our food.  Nuts are higher in phytic acid than either beans or grains.

http://chriskresser.com/another-reason-you-shouldnt-go-nuts-on-nuts

Based on research done with chickpeas, soaking will remove some but not all of the phytic acid.  Dehydrating and then roasting will remove the rest IF you roast at 140f or higher.  Supposedly, that temperature does not alter the nature of the delicate oils in the nuts but it will kill some of the other nutrients.

So, there is a tradeoff.  You need to decide how much phytic acid you can live with.  This guy, http://www.marksdailyapple.com/nuts-and-phytic-acid/, doesn't think we need to worry about it in the small quantities that nuts are generally eaten.

And that brings me to my question:

My SWAMI lists only "walnuts" as a diamond.  It does not specify "walnuts, soaked" as it does for both lentils and pinto beans.  Nor does it specify that they should be either raw or roasted. LR4YT states walnuts are beneficial for every blood type because they inhibit ODC.  Which part of the walnut inhibits ODC?

Walnuts are quite bitter.  It is known that bitter foods offer many nutritional benefits: http://www.myindigestionremedies.com/bitter-foods-for-better-digestion.  

This Whole Foods web page, http://www.whfoods.com/genpage.php?tname=foodspice&dbid=99 , says that 90% of the phenols in walnuts are found in the bitter skin which should not be removed.  

When I soak walnuts, they lose most of their bitterness.  Do they then also lose most of their benefits?  Is the bitterness the reason walnuts are so beneficial?

The Whole Foods website goes on to say that the vitamin E in walnuts is the more unusual and  beneficial gamma-tocopherol AND that, "Some phytonutrients found in walnuts - for example, the quinone juglone - are found in virtually no other commonly-eaten foods. Other phytonutrients - like the tannin tellimagrandin or the flavonol morin - are also rare and valuable as antioxidants and anti-inflammatory nutrients. "

Are any one, or all, of these the mechanism by which walnuts inhibit ODC?  Does soaking remove the phenols as well as the phytates?  Do the quinones, tannins and flavonols also leach into the soaking water?  This site, http://nutgourmet.wordpress.com/category/nut-studies/, says it's the tannins that give walnuts their bitterness and that they are removed by soaking.

The only reference I could find to walnuts and ODC was in this book, http://books.google.com/books?id=ED_xI-CEzFYC&pg=PA64&lpg=PA64&dq=in+walnuts+inhibit+ODC+ornithine+decarboxylase&source=bl&ots=QI6-is2mUD&sig=U0aHZdTmlPNVPcekKFfn26RkEq0&hl=en#v=onepage&q=in%20walnuts%20inhibit%20ODC%20ornithine%20decarboxylase&f=false by R. A. S. Hemat.  It states, "Foods that inhibit ODC include walnuts, curcumin, green tea, pomegranates, guava, broccoli leaves, plantain, black currant fruit, bilberry, elderberry, grapes, onion, garlic, dill, tarragon, and chives."  No explanation is given.

In addition, it is known that phytates do offer some health benefits: http://www.longecity.org/forum/topic/42203-health-benefits-of-phytic-acid/.  

So, should I be eating my walnuts soaked or not given that I have no trouble digesting them either way?

not a prerequisite if not stated

we need to make our personal choices given our health issues etc

sometimes I am in the mood for presoaked, others I eat the raw, and other times I oven toast them, with either sweet of savory finish, depending......
nothing is set in stone here

Quoted from Lola

not a prerequisite if not stated

THANK YOU!!!!

(I take it this means it's OK to soak them, since that is my preference.)

sure, soaking has always been a great means to getting rid of phytic acid, if susceptible.....not everybody is

acidulated water is even better for soaking

I only soak my walnuts for a few hours, until I notice they have swollen up.  I also use salty water, but I do not rinse that off before putting them in the dehydrator. I do dry them for quite a while, at least 24hrs ...

So, my walnuts may still have some of the phytic acid in them, I like to think is the amount my body can use in a positive way, to fight the baddies ... to think of it, they should also have left some of the other nutrients intended to be there ...

I do eat walnuts, but not by the handful, just some here and there ... I think that is the key with all these uncertainties ...  easy does it.... :)  

I prefer mine soaked taste sweeter to me
- sometimes I eat them un dried  sometimes I dry them.
I use salted water and soak anywhere from 6 to 12 hrs depending time.

Quoted from Henriette Bsec

I prefer mine soaked taste sweeter to me
- sometimes I eat them un dried  sometimes I dry them.
I use salted water and soak anywhere from 6 to 12 hrs depending time.

What's your salt-to-water ratio, Henriette?

1 teasp to a biiiig bowl of water-
really not much .

BTW. Thanks for the thread and info. I had never heard of phytic acid before this.  Live and learn.

Your soaking times for raw walnuts and almonds are excessive.  Walnuts = 3 hours.  Almonds = 8 hours.  

Quoted from ElaineP

Your soaking times for raw walnuts and almonds are excessive.  Walnuts = 3 hours.  Almonds = 8 hours.  

That depends on your goal.  Mine is to remove both the phytic acid and the bitterness.  You need at least 18 hours for the phytic acid and it sometimes takes 2 days to get the bitterness out.  It's the only way I can get DH to eat them and I want him to eat them so I do it.

If this is the only way to get DH to eat the walnuts, then keep doing what you're doing. Having them palatable for him is more important than getting "the perfect balance of nutrients" in them, as eating them in any form (soaked, partially soaked, or unsoaked) will provide him with nutrients he won't get without nuts in his diet.

It is possible to over-think things and make food prep way more complicated than it has to be. It's crazy to prepare nuts several different ways to accommodate  the  different preferences of various family members.

The question, really, is whether or not you also want to eat some unsoaked nuts occasionally, if you feel you need more phytic acid in your diet than you're otherwise getting.

"If I soak for 2 days, I dry for 2 days.  Pumpkin seeds seem to take longer to dry -- a 4 hour soak may require 2 days in the oven."

Do you not find that it gets very expensive doing all that?
I accept all your points for doing it...just I couldn't afford to have my oven on for two days straight!

My oven has 6 trays and a 'dehydrate' setting so I'm able to do 6# at a time at 118F which is just like running a dehydrator.  I may spring for a dehydrator that would enable me to make 9 trays simultaneous but I'd need a place to put it.