Grinding, the av melachah of tochen, is forbidden on Shabbat. The purpose of grinding is to break a large object into smaller pieces which can serve a new or better purpose.1 Any act which yields this result is included in the melachah of tochen, with some exceptions:

  • Food which does not come from the ground and can be eaten without further preparation is not included.2 For example, one may shred cooked meat or slice a block cheese.
  • Food which is being prepared for a meal that will soon follow (even if the preparation takes a long time) does not fall under the melachah of tochen.3 One may not, however, use utensils which are made to grind foods, like a grater or masher, even if the food will be eaten immediately.4
  • Something which has been previously crushed and then reformed into a mass may be crushed again.5 For example, one may crush a cookie into crumbs, because the flour, which is the primary ingredient, was previously a grain of wheat which was crushed itself.
  • In certain cases, tochen will be permitted if it is done differently from how it is usually performed.6 For example, one may mash a banana with a spoon since a fork would typically be used. One can prepare food this way even if the meal does not immediately follow.

Grinding in the Mishkan

Various dyes were needed for textiles in the Mishkan. The dyes were made by grinding herbs into a powder and mixing it with water.7 Others trace the melachah to the grinding of wheat for the lechem hapanim, the showbread, which was baked fresh in the Mishkan each week.8

Toladot of Tochen

  • Breaking logs of wood into smaller chunks/pieces, for firewood9
  • Cutting strips of material from a cloth
  • Crumbling a lump of earth
  • Dicing vegetables finely10

Rabbinic Prohibitions: Medicine

In Talmudic times, medicine was produced by grinding the necessary substances, usually various herbs and plants, into powder. Since this process involves tochen, halachic authorities forbade the use of most medicines on Shabbat.11 This prohibition includes any exercises, remedies, or therapies which improve one’s health, even if they do not include the intake of actual medicine, provided that they are for relatively mild ailments. Serious illness and extreme pain were never included. Certainly, to save a person’s life, any and all medicines are not only allowed but required.12

Common Activities to Avoid

  • Cutting up a salad early Shabbat morning for a meal that will take place much later in the afternoon.13
  • Using a grater or masher (even if one intends to eat the food right away).
  • Taking certain medications (consult with a rabbi before Shabbat).