Alms Tax: Zakat on Mixed Quality Produce

Practical Laws of Islam as per the teachings of Ayatullah Sistani

Ruling 1911

If some of the wheat, barley, dates, and raisins on which zakat has become obligatory is of superior quality and some of it is of inferior quality, the obligatory precaution is that one must not use inferior quality produce to give zakat that is due on the superior quality produce.

-Ayatullah Sistani, Practical Laws of Islam, Alms Tax (Zakat)