Winnowing, the av melachah of Zoreh, is forbidden on Shabbat.1 Winnowing refers to the act of removing chaff from grain, using a tool to throw produce into the air, whereby the wind blows the lighter chaff away from the heavier kernels.

Halachic authorities disagree about what exactly is included in this melachah. Some assert that Zoreh refers to the separation of foods and non-foods, specifically using the wind, as it was done in the Mishkan.2 Others maintain that wind is not required, and Zoreh refers to the separation of food from non-food, specifically at the stage when the kernels are still together with their chaff. All later refinements of the food are not included in Zoreh, regardless of the method.3

The Jerusalem Talmud adds that Zoreh can also include scattering things into the wind that does not involve separating foods from non-foods,4 for example, spitting into the air, causing droplets of saliva to fly all over. The leading halachic authorities adhere to this understanding of the law,5 which provides context to what is otherwise a rather uncommon melachah. Based on this, one shouldn’t shake a tablecloth outside after a meal, nor should one blow dust off a book cover.

Zoreh in the Mishkan

To produce the flour needed for the lechem hapanim (showbread) and some of the sacrifices, grain needed to be winnowed after it was threshed.6 Likewise, plants were winnowed to obtain the seeds that were used to make dyes for parts of the Mishkan.7

Toladot of Zoreh

  1. Winnowing by throwing produce into the air with one’s hands instead of a tool.8
  2. Removing kernels from their chaff by hand.9