The view closest to the truth is that adopted by the author. The evidence is the Prophet’s ﷺ statement: “No zakat is due on less than five wasqs.” (1) This indicates that measurement by wasqs is to be taken into account. Tawsīq means loading, and a wasq is a load. It is known that a wasq is sixty sāʿs according to the Prophet’s ﷺ sāʿ. According to the measurements of our shaykhs, this amounts in our sāʿs to two hundred and thirty sāʿs plus one prophetic sāʿ. Based on the weight we have adopted—taking a sāʿ as 2.04 kilograms—three hundred sāʿs of sound, high-quality wheat equal 612 kilograms. A container holding this amount by weight, or several containers, may therefore be used as a standard for measurement.
In summary, zakat is due on grains and fruits, on condition that they are customarily measured by volume and stored. If they do not meet these conditions, no zakat is due on them. This is the view closest to the truth and the relied-upon position, Allah willing.
Issues:
First: The scholars, may Allah have mercy on them, differed concerning grapes that cannot be made into raisins, for some grapes do not become raisins no matter how much they are dried.
Some said that no zakat is due on them, because they are treated like other fruits and are eaten as fruit.
Others said that zakat is due on them even if they cannot be made into raisins, just as dates may be such that they can only be eaten fresh. This is the practice of people today: they collect zakat from grapes even when they cannot be made into raisins.