Work Category 8, Grinding
טוחן

The prohibition of grinding includes all activity by which a substance is reduced to smaller particles for improved utilization.

This law operates under four variables:

1. The type of implement being used:

A) It may be an implement specifically designed for grinding, grating or chopping, such as mill-stones, mortar and pestle, grater or chopper or,

B) the implement may be one not specifically designed for this purpose and yet is being used to accomplish the same task, such as, using a knife to reduce food to particles.

2. The type of substance being reduced.

A) The substance may be something which grew in the earth, such as corn, coffee, onions, vegetables, or fruits or,

B) it may be a food product not grown, such as cheese, meat or salt or,

C) it may be a non-food product such as wood, metals or mud.

3. The size that the product is being reduced to:

A) The particles may be reduced to a size that product is usually reduced to (henceforth called normal size) or, B) the particles may be reduced to a size larger than the normal size.

4. The intended time when the reduced product will be used:

A) It may have been reduced for immediate consumption or for consumption at the present meal under preparation or,

B) it may have been reduced for use at a later period of time.

The laws governing these variables operate in the following manner:

1. The use of an implement which is specifically designed for grinding, grating or chopping is always prohibited even for immediate consumption. (refer to 1A & 4A).

2. There is a dispute among the Sages if it is prohibited to use an implement not designed for grinding, grating or chopping, to reduce food grown in the earth to normal size even for immediate consumption. The Mishna Berurah rules that the stricter opinion - to prohibit - should be followed. (refer to 1B, 2A. 3A, and 4A).

3. It is prohibited by all in the instance just mentioned to reduce the food for use at a later period of time (refer to 1B, 2A, 3A, and 4B).

4. It is prohibited to use an implement designed for grinding, grating or chopping, on a food product not grown in the earth. Some examples of this prohibition are, using a chopper to chop meats or eggs or a grater to grate cheese (refer to 1A and 2B).

5. It is prohibited to reduce a non-food product under all circumstances. Some examples of this prohibition are planing wood, filing metals, and crumbling decayed wood or sod.

Scraping or rubbing off dry mud or excrement from clothing or shoes is prohibited because of grinding.

The Sages permitted a Jew to ask a non-Jew to scrape off mud or excrement from the Jew's clothing or shoes because of human dignity. (This permission to ask a non-Jew to scrape the mud would logically apply only if the Jew cannot change into another garment or shoe as, for example, if the Jew is away from home, or is at home but has no other garment or shoe).

Reducing a substance is permitted only under the following conditions: 1. It is permitted to use an implement not designed for grinding, grating or chopping to reduce food grown in the earth to larger than normal size particles for immediate consumption or for consumption at the present meal under preparation. (refer to 1B, 2A, 3B, and 4A). 2. It is permitted to use an implement not designed for grinding, grating, or chopping, to reduce a food product not grown in the earth to normal size particles even for later use on Shabbos (refer to 1B, 2B, 3A, and 4B).

It is prohibited to reduce a substance grown in the earth which cannot otherwise be eaten by a person for reasons of age or infirmity. Some prohibit mashing a banana for an infant who cannot eat it as a solid. But it would be permitted to mash the banana through an unusual method as, for example. to use the handle of a fork to mash it instead of the tines.

Medicine:

The Sages prohibited taking medicine on Shabbos. (Medicines are made by pounding and grinding, and the Sages feared that people would violate the prohibition of grinding. They prohibited the use of medicine even, where grinding is not necessary).

The Rabbinical prohibition of taking medicine does not apply to cases where a person must remain in bed due to illness and certainly does not apply if there is even a remote danger to life.

A competent Rabbi should be consulted for a decision in specific cases.

Everyone must familiarize himself with these laws before a crisis arises. To search for a Rabbi afterwards would only increase the danger.

Work Category 9, Sifting
מרקד

One who sifts in order to remove worthless matter transgresses this biblical prohibition. Therefore, it is prohibited to sift matzoh meal to remove worthless particles.

It is a Rabbinical transgression to sift in order to break up lumped matzoh meal even though he does not remove any worthless particles.

Work Category 10, Kneading
לש

The prohibition of kneading includes all activity by which small particles of a substance are formed into a dough or paste by the addition of a liquid. The definition of dough or paste is the normal thickness of the mixture of the particular substance as it is generally used. (Of course this excludes a generally loose mixture, which cannot be defined as a dough or paste).

This prohibition includes substances which are normally mixed with liquid such as flour or clay. Some Sages state that one violates kneading as soon as water is added, while others maintain that mixing must be done to incur this violation.

Some Sages state that the prohibition includes mixing a liquid with substances that do not form a paste, such as ashes and sand, and the violation happens immediately when the liquid is added. Other Sages state that these substances are not prohibited even if mixed with liquid.

Since these prohibitions involve a Biblical transgression, the stricter views must be followed. No liquid should be added to a substance whether or not it forms a paste. And surely no mixing should be done to either type of substance.

Some examples of this prohibition are:

1. Mixing or adding flour with liquid.

2. Mixing or adding clay or cement with water.

3. Adding vinegar to mustard, horse radish, and other condiments which did not contain any vinegar.

4. Putting ground matzoh into a liquid.

5. Adding formula, milk, or water, to baby cereals.

In the last three cases (numbers 3, 4, and 5) and similar ones, a transgression may be avoided by preparing the food using all of the following three methods.

A) The first substance to be put into the vessel must be the opposite of the one normally put in first, during the week. For example, if the first one normally put in is the cereal, then reverse it by putting in the milk and then adding the cereal.

B) Do not use the normal method of mixing which is a haphazard or circular motion. Instead, use a cross stroke (east to west, north to south or the reverse).

C) Do not make the mixture as thick as it would normally be.

NOTE: This is not a situation where one may choose one or two of these methods. All three methods must be employed in preparing the mixture to avoid the prohibition of kneading.

Work Category 11, Baking
אופה

The prohibition of baking includes all instances where a substance is improved by fire or heat.

One is guilty of baking by placing a substance in direct contact with a flame or by placing the substance into an oven. It is even prohibited to place the substance into something which has been heated but is not a source of heat. For example, to place an egg into a heated cloth.

Some examples of this prohibition are:

1. Baking

2. Cooking

3. Frying

4. Roasting

5. Melting (wax, fats, pitch, metals, etc.)

6. Placing wood in an oven to dry.

The degree of heat necessary to violate this prohibition is of a temperature defined as "Yad Soledes Boh." Some Sages define this as 125 degrees F = 51.66 degrees C. Others define this as a degree of heat which would scorch an infant's stomach. Since we do not know the exact temperature, we must be careful not to use any fire of a temperature which would make one recoil his hand.

It is prohibited to stir or turn over food in a pot on a fire. The food at the top of the pot may not be fully cooked and by stirring or turning it over, the side that was opposite the heat will now be facing the heat and will cook better, or it may fall to the bottom and may cook faster.

Removing food from a pot while it is on the fire has the same effect in many cases as stirring.

If the food is completely cooked one may remove the pot from the fire and then remove the contents of the pot.

NOTE: Once the pot containing food is removed from the fire it may not be returned to the fire under most circumstances. (The particulars of returning a pot will be discussed later in this chapter). Therefore, in order to avoid the problems of stirring or turning over food, and of returning a pot to the fire, it is best to keep the Friday night and Saturday noon meals in separate pots.

The following terminology must be defined before the relevant laws of baking are discussed.

The contents of a vessel cooking over a fire are called the "first vessel" (K'lee Rishon). When the contents of the "first vessel" are poured into another vessel which is not over the fire the contents of that vessel are termed the "second vessel" (K'Iee Shane). When the contents of the "second vessel" are poured into another vessel which is not over the fire, the contents of that vessel is termed the "third vessel" (K'Iee Shleshe), and so forth.

Some Sages state that only pouring from vessel to vessel lowers the temperature, and renders the contents of the "first vessel" that of a "second vessel" etc. But if a ladle is put into the "first vessel" the contents of the ladle are still considered as a "first vessel" because no pouring took place.

We shall now discuss the laws applicable to this terminology:

1. The law considers a "first vessel" as capable of cooking even after it was removed from the fire, as long as it retains the temperature of "Yad Soledes Boh." It is therefore prohibited to place food in a "first vessel" or to pour from a "first vessel" (that is "Yad Soledes Boh") onto a food which could be cooked.

2. The same law as a "first vessel" applies to a "second" vessel" in cases where the solid or liquid is being cooked or boiled for the first time. If, however, the solid or liquid was once fully cooked or boiled then it may be reheated in a "Second vessel" (but not in a "first vessel"). Therefore, a baby bottle containing milk or food may be steeped but not completely submerged in a "second vessel" to be warmed (since milk was once cooked during pasteurization).

3. One may put food into a "third vessel" or pour from a "third vessel" on food without fear of cooking.

The Sages prohibited placing food on fire or coals before Shabbos to cook on Shabbos. They feared that a person may stir the coals or enlarge the fire to hasten the cooking. This prohibition applies to gas and electric burners as well.

The following procedures may be done to prevent a person from forgetting and adjusting the fire. If any one of these procedures is done then the prohibition of the Rabbis does not apply.

1. The coals or embers are removed or,

2. The coals or embers are covered with sand or,

3. The fire is covered (for example, with a metal "Blech") and the adjusting knobs of the range are made temporarily inoperable (for example, by covering the knobs with the tin or pulling out the knobs). Some Sages state that covering the fire with a "blech" and not making the knobs inoperable is sufficient because the person will not see the fire and will have no thought of adjusting the fire. But many Sages require the knobs to be made inoperable (as stated above). In each of these three cases the Rabbinic fear that a person may forget and adjust the fire no longer exists because the means of adjusting has been removed. Therefore, consult a competent Rabbi on which procedure to follow.

4. The food cooking on the fire is of a kind that will take a long time to be cooked. Therefore, since the food will not be ready for the Friday night meal, there is no fear of adjusting the fire to hasten cooking.

5. The food to be placed on the fire was cooked sufficiently before Shabbos to be considered edible. Since it is edible, the Sages no longer feared that a person would forget that it is prohibited to adjust the fire on Shabbos. The Sages defined the minimum amount of cooking needed to be considered edible as one-third of the cooking process. For example, if a certain food needs one hour of cooking to be completely cooked, then twenty minutes (one-third) of cooking is considered edible. Therefore, if the food was cooked prior to Shabbos for twenty minutes it may then be put on the fire or burner before Shabbos. If food is being cooked in a liquid, it must be noted that the cooking time starts after the water has been heated. Therefore, in the above example, the full cooking time is one hour after the water was heated.

It is forbidden to completely conceal warm food in insulating material including aluminum foil, if the material touches the food, or the food's container, on all sides, if his intention is to preserve the warmth of the food. However, he is permitted to wrap it in aluminum foil if he does not need it to preserve the heat, but in order that the food does not dry out, or to keep it clean.

Some examples of this prohibition are:

1. Completely submerging a food packet or a baby bottle in warm water. The water level must remain below the height of the food that is in the container.

2. Putting warm food or warm liquid in a thermos bottle if the food reaches the cover.

If the food was concealed in insulating material before Shabbos and was removed on Shabbos, it may be returned there on Shabbos.

It is permitted to put food in an oven warmer that is not thermostatically controlled because the oven does not touch the food on all sides.

If he poured the food from the original pot into a different pot, then it is permitted to conceal the second pot with insulating material.

If the food was not warm, he may conceal it with insulating material to prevent it from becoming cold.

If the food is wrapped in insulating material it is forbidden to put it on a hot-plate or a hot "blech" even before lighting the candles of Shabbos. The proper way to do it is to leave the wrapping somewhat open on one side before placing it on the heat.

There are certain insulating materials that are forbidden to conceal in them food even before Shobbos, even if the food is cold, even if it is not in its original container wherein it was processed, and even if it is only partially covered with this material and the rest of it with regular insulating material.

Some examples of these insulating materials are:

1. Sand

2. Salt

3. Straw

4. Lime

5. Raw wool or cotton

It is permissible to recook, or reroast or rebake solid food. But it is prohibited to cook roasted food, or roast cooked food or bake cooked food. Therefore, a cooked piece of meat should not be placed before a flame because it may become roasted. Piece of meat that was roasted should not be placed in a pot with gravy because it may become cooked.

The Sages prohibited returning cooked, roasted, or baked food to a fire or "first vessel" because of many possible violations of Shabbos including the aforementioned. (That is they feared that cooked food would become roasted, roasted food would become cooked etc.)

However, a pot removed from the fire which has not cooled and has not been put down on a surface may be returned to the fire. If one of these two factors is not present, the pot may not be returned to the fire. For example, if the pot cooled it may not be returned; or if the pot was put down on a surface, even if it has not cooled, it may not be returned.

One custom is to hold the pot over the "blech" when removing some of its contents in order to avoid the problems of cooling down or being put down on another surface.

If a pot with food is on the "blech," and the "blech" is "Yad Soledes Boh" that pot may be moved around on the "blech," even to a hotter spot.

A dry solid or a liquid may be put in a place to warm if the temperature of the food will never become "Yad Soledes Boh." But if the temperature could become "Yad Soledes Boh", even after many days, it is prohibited to place the food there. (This applies even if one intends to remove the food before it heats up to "Yad Soledes Boh.")

It is permitted to place a solid or liquid in the sun to warm. But it is not permitted to warm food with a solar furnace.

It is forbidden to open a hot water faucet because, as the hot water leaves the boiler, cold water replaces it, and is cooked. If he accidently opened it, he must close it immediately unless the water is no longer hot, and if so he is not permitted to close the hot water faucet. On Yom-Tov, it is permitted to open and close the hot water faucet.

Electric kettles that work with a thermostatic control that is constantly turning the heating coils on and off, are forbidden to use on the Sabbath. If it does not work with a thermostatic switch that constantly turns the heating coils on and off, with the exception when cool water is added to the kettle, then it heats the water until it reaches a fixed temperature and thereafter the heating coils remain at a non variable fixed heat level all the time, and furthermore, it must not have a functional water level indicator, then it is permitted to pour water from this kettle but it is forbidden to add water to it.

It is forbidden to put dirty dishes into a dish-washing machine that is set to turn on, on Shabbos, because the hot water pours directly onto the food stuck to the plate and cooks it.

It is forbidden to cook with a microwave oven even if it is set by a timer because the microwaves are considered a secondary source of heat, which is Biblically prohibited.