noun
30% polished rice; rice milled to 70%
Technical term for rice that has had 30% of the outer bran layer removed, leaving 70% of the grain. Used in contexts like sake brewing or health food.
三分搗き米は、白米より栄養が多い。
Rice milled to 70% has more nutrients than white rice.
70% polished rice (only 30% of bran remains).
Fully polished white rice, with almost all bran removed.
Compound of 三分 (さんぶ, 'three parts' or '30%') and 搗き (つき, 'polishing' or 'milling'), from the verb 搗く (つく, 'to pound' or 'to hull').