But the lunch box prepared like this can't be kept in the refrigerator for a long time, which will lead to its deterioration. And lunch boxes are usually kept in the refrigerator.
Because the water in rice will solidify at low temperature, the rice placed in the frozen layer will become particularly hard and cannot be recovered no matter how it is treated. But the rice placed in the fresh-keeping layer will be the same as fresh rice, so it is generally recommended that you put inexhaustible rice in the fresh-keeping layer or freezer in the future.