גדר בישול מים – 09

And one who boils - Whether he cooked food, or spices, or water, and whether he cooked bread –– it's all one thing. And one who soften one of the types of metals any amount or he heats the metal until it becomes a coal –– he has violated a subcategory of bishul. And someone who dissolves wax, or fat, or pitch, or cyprus flower, or sulphur, or anything similar –– he has violated a subcategory of bishul. And, so too, someone who boils dirt until it becomes pottery –– he has violated bishul. And, so too, someone who puts pieces of wood in the stove in order to dry them, and he knows that at first they are most, but that the moisture will come out of it –– he has violated bishul. The rule is: Whether it's the burning of something hard in the fire or that it is hardening something soft –– he is violating bishul. Therefore, you should be very careful to not place moist wood over a stove to dry them.

A person who bakes [an amount of food] the size of a dried fig is liable. Just as a person is liable for baking bread, he is liable for cooking food or herbs, or for heating water. These are all one type [of activity]. The minimum amount of water for which one is liable for heating is an amount sufficient to wash a small limb. The minimum amount of herbs for which one is liable is the amount required to serve the purpose for which they are being cooked.

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One who grinds the size of a dried fig is obligated.... All of these sizes are by melacha by food [as apposed to liquid] that they are equal and the size of a grogros. And in perek "Klal Gadol" it give the case case of harvesting and grinding the size of a fig. And this is clear.

A person who melts even the slightest amount of metal or who heats a piece of metal until [it glows like] a coal performs a derivative [of the forbidden labor] of cooking. Similarly, a person who melts wax, tallow, tar, brown tar, or pitch, and the like performs a derivative [of the forbidden labor] of cooking and is liable. Similarly, a person who heats an earthenware utensil until it becomes hard clay is liable for cooking. The general principle is: Whether one softens a firm entity with fire or hardens a soft entity, one is liable for cooking.

Rav Yehuda said that Shmuel said that the halakha is: With regard to both oil and water, heating either one to the point where the hand spontaneously recoils from it is prohibited. Heating either one to the point where the hand does not spontaneously recoil from it is permitted.

If the water becomes yad suledes it has changed and is no longer water.

(3) A person who breaks open an egg over a warm cloth, over sand, or over the dust of the roads that are heated by the sun is not liable even though it becomes roasted, for the derivatives of the heat of the sun are [governed by] different [laws than those governing] the derivatives of fire. Nevertheless, the Sages instituted a decree forbidding cooking with [the derivatives of the heat of the sun], lest [one cook with] the derivatives of fire. Similarly, a person who cooks using the [hot] springs of Tiberias and the like is not held liable.
A person who cooks food that has been completely cooked, on a fire, or who cooks food that does not need to be cooked at all is not liable.

(4) 4. Fruit that is usually eaten raw is permitted to be place around the pot, even though there is not sufficient time for them to roast [completely] before dark. However it is necessary to be careful not to return the cover if it is close to dark and not to add to it because one will be hastening [the fruit’s] cooking on Shabbos.

(6) A person who melts even the slightest amount of metal or who heats a piece of metal until [it glows like] a coal performs a derivative [of the forbidden labor] of cooking. Similarly, a person who melts wax, tallow, tar, brown tar, or pitch, and the like performs a derivative [of the forbidden labor] of cooking and is liable.
Similarly, a person who heats an earthenware utensil until it becomes hard clay is liable for cooking. The general principle is: Whether one softens a firm entity with fire or hardens a soft entity, one is liable for cooking.