When you make some kind of porridge by boiling either ground cereal seeds (i.e. some kind of coarse cereal meal, e.g. cornmeal or semolina) or whole cereal seed

When you make some kind of porridge by boiling either ground cereal seeds (i.e. some kind of coarse cereal meal, e.g. cornmeal or semolina) or whole cereal seeds (e.g. of rice or wheat or barley), they will absorb a quantity of water of at least four times the mass of the cereals. Therefore the cooked food will be much more voluminous than the original cereals. Both Pyrocystis noctiluca and the boiled cereal seeds increase their volume many times by absorbing water, but Pyrocystis noctiluca keeps the water in internal vacuoles, while in the boiled seeds the water is incorporated in their starch granules. All starchy seeds absorb water when boiled, but most of them do not absorb so much water as the cereal seeds, so their increase in volume is lower.