According to the 'Standard for dried buckwheat noodles' under the 'Japan Agricultural Standards (JAS) for Dried Noodles,' soba with a minimum of forty percent buckwheat flour content is rated as standard quality and that with a minimum of fifty percent buckwheat flour content is rated as superior quality.
「乾めん類の日本農林規格」(JAS)の「干しそばの規格」において、蕎麦粉の配合割合が40%以上の麺を標準品、50%以上の麺を上級品としている。