One of the 39 Melachot. This includes all activities where food is separated from its inedible portions by means of the wind.

The prime example is winnowing grain, where it is thrown up in the air, allowing the chaff to blow away.

<< Prev Full Next >>

Most of this information is taken from the book "SABBATH Day of Eternity" by Rabbi Aryeh Kaplan, published by NCSY. In the book itself, there are notes that refer the reader to detailed footnotes. I am lucky to have found such a clear, concise manual with these brief overviews of laws so vast and complex there are Rabbis that specialize in them.