Ricyness in cauliflower is due to

Riceyness is a premature initiation of floral buds in cauliflower characterized by riceyness. In this case, the peduncle elongates and the curd becomes granular and loose.
Curds of the flowers become loose, velvety, appearance, elongation of pedicel and formation of small white flower bud at the curdling stage. the main factor responsible for this is the fluctuation of temperature.