Soaking Basics

There are so many fantastic sites now that go into great deatil on this subject, so I wanted to offer a stripped-down, simple guide for readers to follow. If you're a food science nerd like me, I dare you to google it! I'll even offer some links below to some of my favorite bloggers who have done the work and the research to offer a more in-depth treatment of soaking/fermenting grains, nuts and legumes.
 In a nutshell (no pun intended), grains, nuts and legumes contain phytates, and/or anti-nutrients that interfere with the absorption of the nutrients they contain (as well as the nutrients of other foods you may consume along with them). Soaking, sprouting or fermenting these items neutralizes some of the phytates and anti-nutrients, rendering them more digestible and nutritious. Our ancestors didn't know the word "phytate," nor had they ever peered at their food under a microscope. However, their traditional wisdom included the practice of properly treating grains before consuming them, and we have almost completely lost that wisdom. Consuming grains that have not been properly treated can lead to serious vitamin, mineral and enzyme deficiencies. To reduce your risk of harmful levels of phytates and anti-nutrients, follow the basic guidelines from Nourishing Traditions, by Sally Fallon:

Whole Grains 
1 cup grain
2 tablespoons of an acid*
warm filtered water, enough to cover

Put all into the cooking vessel you plan to use to cook the grain, and let soak for a minimum of 7 hours and up to as long as 24 hours. Then cook as usual, skimming any foam or scum that develops on top, as it can contain released impurities.

*For the acid, you can use plain yogurt, whey (from milk, yogurt, kefir, etc.), kefir, buttermilk, vinegar, or lemon juice.

Nuts and Seeds
4 cups raw nuts or seeds
1 tablespoon sea salt 
warm filtered water, enough to cover

Leave them to soak in a warm place for 6 to 8 hours - please see the note on cashews below. Drain off the water (do not rinse them), and pat them dry with a towel. Seeds are air-dried at room temperature, and nuts can be air-dried too, or they can be dried in the oven.

Spread nuts out on a cookie sheet and dry them in the oven on the lowest heat possible for 12-24 hours depending upon the type of nut - the temperature should not go above 150°F since it can burn them. They can also be dried in a dehydrator at 150°F or lower. Store nuts and seeds in glass containers with tight fitting lids, and keep them in the refrigerator.

Special Notes:
Almonds are now being irradiated (zapped with radiation) in most countries, which change and damage the body's cells if consumed, so no one should have them.

Candida sufferers should not have cashews, peanuts, or pistachio nuts. Cashews are processed even if they are labelled "raw," and peanuts and pistachios contain mycotoxins (fungal-type toxins).

Nuts and seeds are a wonderful snack and they can also be ground into flour. Always buy raw nuts or seeds that are not toasted or roasted because they contain man-made oils that are damaging to health.

Some nuts, like pecans, only require the oven light to provide enough heat to dry them without burning them - they shouldn't be left in the oven for more than 4 hours, and then they should be air-dried the rest of the way. Some ovens will require the oven door be propped open with rolled towels to keep the heat in and the light on at the same time.

It is better to be cautious when drying nuts in the oven, even when only using the oven light, because they can burn very easily. They can also be dried at room temperature but it will take longer. Ensure the nuts and seeds are totally dried before storing them or they will have more of a tendency to mold. If you aren't sure they are completely dried, put a paper towel in the jar, with the lid on tight, for 24 hours to soak up the moisture, and then refrigerate them.

Cashews are the exception to long soaking time. Do not soak them more than 7 hours. They have already been through one soaking in their initial processing. If they are soaked too long they will be bitter. They may be crisped in the oven at a higher temperature because they have already had their enzymes destroyed by high temperature used during their commercial processing.

There is a great debate and some fantastic scientific information here

A more in-depth article here

"Nourishing Traditions: The Cookbook that Challenges Politically Correct Nutrition and the Diet Dictocrats," by Sally Fallon with Mary Enig, Ph.D., Weston A. Price Foundation (WAPF).