Why should you soak your beans? Because it is better for your health, comfort and pocket!
Many think the main reason to soak beans is to minimize gas, and while it’s true that soaking does help to remove the indigestible complex sugars (oligosaccharides) from the outer coating of the beans, it’s certainly not the primary reason to soak.
Probably the most important reason for soaking is that it that preserves the most nutrients because it requires less 
time to cook, so you get the benefits of all the proteins, vitamins and minerals in the beans and maximize their food value. According to the California Dry Bean Advisory Board, there’s no need to worry that soaking is going to remove the proteins, enzymes or other nutrients that are stored within the beans.
Soaking also allows beans to slowly absorb the liquid they need to cook evenly and completely so they don’t split open, lose their skins, or cook only the outer surface while the middle remains hard.
Soaking cuts the cooking time by as much as 70%, so most soaked beans will pressure cook in as little as 8 to 15 minutes. That saves you — and your wallet — a bit of cash in using less cooking fuel, and that in turn, means that you can help the environment by using less energy with shorter cooking times. If you fail to soak the beans first, a large part of the cooking time (and energy expense) is wasted while the beans rehydrate to the point where they actually can begin to cook and soften, extending the cooking time to 40-60 minutes.
And lastly, soaking helps further break down those pesky oligosaccharides, the indigestible sugars that cause gas in beans, as well as removing tannins, phytic acid and tryspin inhibitors.
Don’t use the soaking water to cook the beans in, not only does it contain all the gas causing, indigestible complex sugars of oligosaccharides that have leached off the outer coating of the beans, but also all the other stuff that came off the beans.
Doesn’t sound so yummy if you stop and think about it, does it? So let’s drain off the old dirty water the beans have been soaking in, and give them one final rinse before putting them in the pan and adding more fresh, cold water for cooking.
I like to use a glass bowl to soak beans because small amounts of metal can leach into the water when using metal bowls or cookware like a the pressure cookers. Plastic containers often have a sticky, hard to clean and unseen residue of accumulated oil and fats that may impart unwanted odors and taste.
Soaking is really simple. All it requires is time really. You don’t have to watch them soak. Just put them in the bowl and go about your day. I will put them to soak before I go to bed and then rinse it in the morning or put them to soak while making breakfast or after doing lunch dishes so they can get 4hr or more of soaking if I am making them for lunch or dinner.
Most beans require 4 hrs to soak. The harder the bean the longer it should soak. Garbanzo beans for example should soak for at least 8 hrs, so overnight is the best.