As humans have evolved over thousands of years they found numerous ways through trial and error to maximize the nutritional value of their food. We still see some of those practices in place today, like the addition of ash or lime to maize to make masa, or the natural pickling of vegetables like cabbage to soften their fiber and preserve them in sauerkraut or kimchi. One tradition we don’t see very often anymore is the process of soaking grains before cooking them. So why does it matter if we do this? First, we need to understand what grains are and how they behave.
All grains are seeds, and seeds are resilient. Like us, they have evolved to survive and reproduce. They have all the genetic information that their plant requires to grow as well as stored food to get the plant going. For humans to get the most nutrients from consuming those seeds, they need access to that stored food, but it takes some help. In nature, the first step of germination is called imbibition, where the seed absorbs water and swells, breaking the “seed coat”. This process activates the previously dormant seed, including enzymes that break down the stored food into chemicals that can be metabolized. For the evolving human with less secure access to food, activating the seeds before eating them kept them sated longer. If you and I had a cup of grains, and I soaked mine and you didn’t, you would get hungry again before I did. A more formal term for the result of soaking grains is pre-digestion—we are converting the food into something that is easier for our body to digest before we even start to eat, and in turn, unlocking all of those previously stored nutrients.
"If you and I had a cup of grains, and I soaked mine and you didn't, you would get hungry again before I did"