Seeds Concentrate Cooking Liquids

Because grains and beans are dry and soak up water, they remove water from the liquid they’re cooked in, and therefore effectively concentrate other materials in the liquid. In this way they create a sauce for themselves. When rice or polenta is cooked in milk, for example, the liquid between the grains becomes richer in both milk proteins and fat globules, and so more like cream. When grains are cooked in a meat stock, the stock become more concentrated in gelatin, and so comes to resemble a reduced stock or demiglace.