Tochen

Definition

1. The melacha is defined as the constructive reduction of a large singular entity into small parts whereby it serves a new purpose. Examples include chopping wood into small chips for a fire, shaving down a metal rod to form small strips or dicing vegetables to cook them.
2. There is a biblical violation of grinding when grinding wheat, barley, spices, spices, and the like. Similarly, it’s biblically forbidden to saw wood for the sawdust.
3. The prohibition of Tochen (grinding) includes chopping, grating, crushing, mashing, shredding, or breaking something into small pieces.
4. Tochen also applies to non-foods. For example it's forbidden to crush a clod of dirt, shave splinters off a piece of wood, sawing wood with intent for the dust.

In the Mishkan

1. Tochen (grinding) was performed in the mishkan in the process of crushing herbs to make dyes.

Utensils designed for grinding

1. Any tool which is designated for crushing or the like such as a mortar or a knife used only for dicing may not be used in any manner even if it doesn't involve any prohibition of Tochen.
2. One should not use an onion slicer (a machine which is made of a set of knifes that surrounds the onion and dices it).
3. A vegetable chopper (with blades fitted with springs on an axis) is forbidden since it chops vegetables thinly.
4. An egg slicer (with equally spaced wires that slice the egg when pressed) is permitted.
5. A special cheese knife isn’t a utensil designated to be used for chopping finely.
6. One may cut bread in a machine (manual, non-electric) which cuts slices of bread.
7. It’s forbidden to grind coffee beans it a grinder meant for it.
8. It’s permissible to cut vegetables on a cutting board even if it makes line in the board.
9. It’s permissible to use a peeler to peel vegetables on Shabbat.

For immediate consumption

1. Since there are some who hold that it is permitted to cut up raw vegetables or fruit for "immediate" consumption, and there are others who forbid, many poskim write that one should only cut up the vegetables or fruit with a knife into somewhat large pieces for "immediate" consumption. Sephardim hold that for immediate consumption it is permitted to cut up a vegetable even into small pieces. However, it is praiseworthy to be strict to only cut it into big pieces. The above leniency is only if one uses a regular knife but not a special grinding utensil.
2. It is also considered "immediate" if one makes the salad right before beginning the meal in which it will be eaten.
3. The above leniency applies whether one is preparing for one's own immediate consumption or another person's immediate consumption.
4. If one made a salad for one meal and there was left over one is allowed to eat it in another meal.
5. For a child or someone who can't eat large pieces there is what to rely on to cut it up into small pieces as long as one does so right before the meal.
6. It's forbidden to crush a banana or avocado unless it's already so soft that when one pulls a part of the fruit, that part separates from the rest of the fruit.
7. There is a debate amongst the Poskim if the prohibition of Tochen applies to fruit or vegetables such as bananas and avocados which when mashed do not separate into individual pieces but rather just change shape and remain one large mass. Therefore, it is better to do so with a shinui.

Cooked fruit or vegetables

1. Fruits or vegetables which were cooked to the point that it's easy to crush may be crushed on Shabbat.
2. Potatoes or vegetables which were cooked may not be put through a strainer in order to puree it (as the strainer is designated for that purpose) but one is permitted to crush it with a fork (even the prongs) as long as it was cooked to the point that it's easy to crush.

Pre-crushed food

1. Food which was made from crushed particles may be crushed on Shabbat (not using a utensil designated for crushed but rather a regular knife) if one is going to eat it on Shabbat. For example, one may crush matza, bread, crackers, chocolate, and sugar.
2. Salt granules which solidified because of a moisture may be crushed on Shabbat, however, one may not crush salt crystals (looking like blocks) or any other spice which has never yet been crushed unless one does two Shinui's (changes) by using the handle of the knife or fork on a plate or the table.
3. Food which was crushed very well before Shabbat or on Shabbat in a permissible may may be further cut on Shabbat even in the normal fashion.
4. One may pour hot water (even from a Kli Rishon) onto farina, rice porridge, or corn flour and mix it around even crushing the clump with a spoon.

Cooked fruits and vegetables

1. There’s no prohibition of grinding concerning fruit or vegetables cooked to the extent that it’s soft and easy to mash such as jam.
2. One shouldn’t use a fork to mash a cooked fruit or vegetable unless it was partly crushed out of shape before or during the cooking and is easily mashed.
3. One shouldn’t use a strainer to puree or cream a cooked fruit or vegetable since the strainer has a designated purpose of being used to mash.

Foods which don't grow from the ground

1. Even though there is an issue of tochen on non-food items as well as food items, foods that do not grow from the ground such as meat, eggs, and cheese are not subject to the prohibition as long as one plans on eating them that Shabbos.

Grinding for a small child

1. One can be lenient to cut a food very small for a small child to eat so long as it’s immediately prior to the meal.
2. It’s forbidden to mash or squash a fruit or vegetable such as a banana or tomato. If one has to mash a banana for a small child one should do it with a variation such as using the handle of a fork or a spoon.

Slicing

1. There is a machloket amongst the poskim if the prohibition applies only if the food is being cut very small in all dimensions or if it even applies if one is slicing in one direction such as an egg or tomato.

Toladot

1. Cutting up vegetables into small pieces in order to cook them and shaving down a metal rod are examples of toldot of Tochen.

Related Pages

1. Taking Medicine on Shabbat (which is a rabbinic decree because of grinding)

==Links==# The Shabbos Kitchen: Slicing and Dicing (Tochen) by Rabbi Shalom Rosner# Back to the Grind on Jewish Pathways