Oven Kashrus: For Yom Tov Use

Yom Tov celebrations could never be complete without the traditional piping hot delicacies from past generations. However, the kosher homemaker must be well educated on how to prepare Yom Tov meals without fear of transgressing a Torah or rabbinic prohibition.

When mentioning the prohibition of work on Shabbos the Torah writes, “Do not do any melacha (work prohibited on Shabbos).”1 This prohibition applies to melacha performed for food preparation, as well as other non-food purposes. In stating the prohibition of melacha on Yom Tov the Torah writes, “You shall not do laborious work.”2

In addition, when giving the initial command about the Yom Tov of Pesach, the Torah writes, “No work may be done on them (first and seventh day of Pesach), except for what must be eaten for any person, only that may be done for you.” (Shmos 22:16) The Ramban explains that the contrast of terms (work versus laborious work) used for Shabbos and Yom Tov indicates the difference between melacha in general and meleches hana’ah. Meleches hana’ah is work done for food and similar necessary pleasures. Where the Torah commands us about the laws of Pesach, the term meleches avodah is not used in the prohibition. However, the Torah immediately includes the clause allowing melachah for food preparation.

This being said, please note that not every melacha may be performed for the purpose of food preparation. Only those melachos which could not have been done before Yom Tov with the same result may be done on Yom Tov. Therefore, one may not originate a flame on Yom Tov since one could have left a fire burning from before Yom Tov. The prohibition of starting a new flame is referred to as molid, giving birth to a new entity.

Melachos which are commonly performed for bulk processing of food (i.e., harvesting and grinding) are prohibited on Yom Tov. We commonly associate those melachos regarding the processing of bread, from the kneading of the dough and onward, as permitted on Yom Tov; those processes that occur before kneading (i.e., sifting and grinding) are prohibited. The focus of this article deals primarily with melachos associated with cooking on Yom Tov (i.e., cooking, burning of a flame) and extinguishing a flame.

It is important to note that melachos permitted for food preparation or other Yom Tov necessities may be done only if the intent is to derive benefit from this action on Yom Tov. One may not cook food on Yom Tov for use after Yom Tov. In fact, one may not cook food on the first day of Yom Tov for consumption on the second day of Yom Tov. This is because the second day is a holiday by rabbinic law only. Therefore, one must be sure not to do any melacha for the second day until the first day has passed and the next night has begun.3

When Yom Tov falls on a Friday, one may cook for Shabbos only if he had already prepared some of the Shabbos food before Yom Tov. This food which is set aside is called Eruv Tavshilin.4 An Eruv Tavshilin is required in preparation for a Shabbos that follows either the first or last days of Yom Tov. With this in mind, let’s take a look at how these rules apply when we set the controls of our ovens and cooktops for Yom Tov.

ELECTRIC COOKTOP

Turning on an electric stovetop to warm food will initiate the flow of electricity to the burner. This is called molid. Halachic authorities have determined that electricity used as heat or light is considered fire. Therefore, by turning on the burner one is creating a new fire. This action could just as well have been done before Yom Tov and is prohibited because of molid.

Turning the dial on an electric stovetop may also initiate a light or icon on a control panel which would otherwise be turned off. This may be a transgression of the melacha of kosev, writing, as well as molid. Even when the electric burner is left on from before Yom Tov, if one wishes to adjust the temperature of the burner there is further reason for concern. This is because as a rule one does not know if there is an electric current running to the element at the time he makes the adjustment.

Even when there is an indicator light showing that a burner is turned on, this may not be an indication that electricity is flowing to the burner at that moment. Rather, it is indicating that the element is set to maintain the desired temperature adjustment by turning on and off at pre-determined intervals. As a result, when one adjusts the temperature upwards on Yom Tov he may be initiating the flow of electricity at a time that it was otherwise not flowing. As mentioned earlier, this would be prohibited due to molid.

To circumvent this prohibition, an electrician can install an indicator light which is attached to the actual flow of electricity to the burner.5 This will indicate when there is a current flowing to the burner. When there is electricity flowing, one may raise the temperature in order to enhance cooking.

Lowering the heat setting on an electric stovetop on Yom Tov is also not without its halachic ramifications. We know that extinguishing a burning log is the melacha of kibui.

Lowering the heat setting of a stove on Yom Tov may be associated with the melacha of kibui. Therefore, this can be done only when it is for the benefit of the food so that it will remain warm but not burn. One may not turn the burner off completely. However, if there is an indicator light showing when power is flowing to the burner, one must be careful to lower the burner only when the indicator light is off.

Note: Most stovetops that come with the Sabbath Mode ovens have not been engineered to allow the adjustment of the stovetop temperature. The stovetop must be treated like a conventional oven, as described above. (See specific model listings for some exceptions.) Induction cooktops use electricity to create a magnetic field that will heat ferrous metal. These units react to the placing or removing of a pot onto the cooking surface and, therefore, cannot be used on Shabbos or Yom Tov.

GAS COOKTOP

Not so long ago, the standard gas cooktop had a pilot light which was a constantly burning flame from which the burner drew its fire. If one has such a cooktop, he may turn on the stovetop during Yom Tov without concern of initiating a flame. Due to safety concerns, the old pilot flames have been basically phased out. Instead, cooktops have been fitted with electronic igniters which spark at the base of the burner to ignite the flame and are prohibited on Yom Tov.

One may turn on a burner only if he can do so without causing the electronic igniters to go on. If it is possible to turn on the gas flow without starting the electronic igniter, the burner may be started by holding a pre-existing flame to the burner (from a candle or a match lit from another burner) when turning on the gas. The easiest option would be to turn on the burner before Yom Tov. It goes without saying that one may increase an existing flame on Yom Tov when it is necessary for food preparation.

As is the case with an electric stovetop, one can only lower the flame on a gas burner when this is done for the benefit of the food. An example of this is keeping the food warm while preventing it from burning. However, one may not turn off the flame completely.

ELECTRIC OVENS

As with cooktops, one is forbidden to directly initiate a fire or heat to an electric coil due to the prohibition of molid. If the oven was turned on before Yom Tov, the temperature setting may be raised as necessary for cooking if one is sure that electricity is flowing to the element at that time or there is no digital readout. Also, one may not cause a light or icon to go on during Yom Tov. If a light goes off and on indicating when power is flowing to the heating element, then the temperature may be raised when the light is on.

Generally speaking, one may lower the temperature only if it is necessary for the Yom Tov’s food and if a light or icon will not be turned off.

If an indicator light displays when power flows to the oven, one may lower the oven temperature when power is not flowing (indicator light is off) even if it is not needed for the food.

Some Sabbath Mode ovens are designed to work on a delay when in Sabbath Mode, the display will not change. In addition, this feature permits raising the temperature on Yom Tov at any time, regardless of when power is flowing to the oven. This is because when one adjusts the dial or keypad, it is not directly causing the temperature of the oven to change. Therefore, this action is considered a grama, an indirect action, which will cause the temperature to be raised. Even with these types of ovens, it is better to lower the temperature only when necessary for food preparation or enjoyment of the Yom Tov. (Other features of Sabbath mode ovens are discussed further in this article.)

GAS OVENS

Older ovens used to be ignited with a pilot light. This is a small flame from which the oven drew its fire when turned on. In halachic terms, this allowed the user to turn on the oven during Yom Tov without a question of transgressing the prohibition of molid.

As with the gas cooktops, new ovens are equipped with electronic igniters most commonly known as a glow plug. When turning on the oven, the power to the glow plug is initiated. When the glow plug is hot enough the gas will begin to flow and start the flame. When the oven chamber reaches the temperature set by the thermostat it turns off the flow of gas and electricity. As the chamber loses heat, the oven will restart the glow plug which in turn restarts the gas in order to bring the chamber back to the required temperature.

Since one may not directly initiate the flow of electricity to the glow plug during Yom Tov, he must turn on the oven before Yom Tov. When raising the temperature of the oven during Yom Tov, one must be sure that he is not initiating the electric current to the glow plug. Therefore, if one sees the glow plug glowing (it gives a bright orange light, which can be seen through the side vents on the floor of the oven) or if the flame is on, one may raise the temperature. As discussed earlier with regard to stovetops, one may lower the oven setting only when needed in order to benefit the food.

It is important to note that some ovens will display a digital readout of the temperature when it is raised or lowered. This would pose a halachic question of writing and erasing, both of which are prohibited acts on Yom Tov.

SABBATH MODE OVENS (the following applies to Yom Tov only)

Sabbath Mode ovens are designed to bypass many of the practical and halachic problems posed by the modern oven. For the Sabbath Mode ovens with the delay feature, one may raise or lower the temperature of the oven without affecting the heating element or glow plug. This is because the computer does not directly react to the change in settings; the oven will adjust the setting only after a delay.

This means that turning on the heating element or glow plug is an indirect result of an action (grama). Therefore, since a grama is permitted on Yom Tov one may actually adjust the temperature on the oven during Yom Tov. For Sabbath Mode ovens without the delay feature, the temperature may be raised only when power is flowing to the oven and lowered when power is not flowing to the oven, as indicated by the readout on the display.6 (Note: The oven will have to be set to Sabbath Mode to prevent issues with the display.

Another issue is that some ovens can be programmed to turn off at a preset time. This feature is known as Timed Bake. In many models, when the time has elapsed and the oven shuts off, it will sound either a bell/buzzer or it will display a readout (such as the word “END”) to indicate that the oven is off. On some models, this buzzer or display will continue until it is manually turned off or until the door is opened, which is not permitted on Yom Tov. On those Sabbath Mode models that include the timed bake feature, the buzzer or readout is eliminated. (Please note that once the timed bake goes off, the oven cannot be used again for that Yom Tov.)

As a safety feature, new ovens are designed to shut off after being on for 12 hours. Although this safety feature is very important, it creates a problem when preparing food for the daytime meal which is more than 12 hours after the onset of Yom Tov. For all types of Sabbath Mode ovens, the 12-hour cutoff is bypassed.

In Sabbath Mode ovens, the door plunger switch is disabled so that it will not directly cause any electronic reaction. On some of these ovens, the cavity light will remain either on or off, depending upon how Sabbath Mode was entered. For other Sabbath Mode ovens, the light must be turned on at the control panel or the bulb must be unscrewed before entering the Sabbath mode.

It is important to note that not all Sabbath Mode models offer the same features. If you have a STAR-K certified Sabbath Mode oven, please check our website at www.star-k.org to see which features are available on your particular model, or contact our office at 410-484-4110.7

Oven Use on Yom Tov: Common Questions and Answers

The following are some commonly asked questions about oven and stovetop use on Yom Tov:

Q. Why is one allowed to push a button on the keypad of a Sabbath mode oven on Yom Tov?
A. Pushing a button on an oven during Yom Tov, when in Sabbath Mode, starts a process internal to the computer without any heat, light, sound, movement or anything tangible that can be perceived. This is not considered a melacha and is permitted on Yom Tov. When a melacha is finally accomplished, namely turning on the heating element in the oven, it is done so through a grama (an indirect act) because there is a delay of 15-25 seconds before the heating elements can be activated. This grama is permitted on Yom Tov, but not on Shabbos.

Q. Can one turn on a Sabbath Mode oven on Yom Tov or Shabbos?
A. No. This is because it directly causes the display to change, which is prohibited.

Q. Can I set the Timed Bake feature on Yom Tov?
A. For those ovens that have the Timed Bake feature included in the Sabbath Mode, it can be set before Yom Tov only. This will allow for one-time usage. Once the oven shuts off, it cannot be used again for that Yom Tov. One may not set the Timed Bake mode on Yom Tov (and certainly not on Shabbos).

Q. May one turn off the stove or oven to conserve energy on Yom Tov?
A. No. One is permitted to lower the setting only when it is necessary for the preparation of food for the Yom Tov.

Q. May one lower the setting on a Sabbath Mode oven even when it is not for the benefit of the food?
A. Sabbath Mode ovens that are equipped with a delay may be lowered on Yom Tov. This is because the reaction of the oven in lowering the temperature is the result of a grama (indirect action). Although we permit extinguishing or lowering a flame only when it is needed for food, this applies where one actually performs the action. In this case, when the computer will lower the temperature later on as a reaction to one’s instructions, it is called gram kibui and it is permitted.

Q. Can I open and close a standard oven door at any time on Yom Tov?
A. On Yom Tov, one may open and close the door of an oven in order to process the food as needed if this does not cause a light or icon to go on as a direct result. On Shabbos, there is a problem with opening the oven door because it will cause additional burning in the oven. This is prohibited on Shabbos8 but permitted on Yom Tov.

Q. Must I wait until I see the glow plug glowing before opening the door to my gas oven on Yom Tov?
A. As a rule, the oven will not immediately go on due to the reduction of heat created by opening the door. Therefore, even though the oven will eventually go on because its door was opened, this is not a direct result of your action. This additional burning is permitted on Yom Tov.

Regarding raising the temperature of a gas oven on Yom Tov, one may not do so unless he knows that the glow plug is glowing (and the display will not change). This is because raising the temperature setting will directly cause the glow plug to go on if it is otherwise off, creating a problem of molid. However, if the oven is Sabbath Mode certified with a built-in delay feature which was initiated before Yom Tov, he may adjust the temperature on Yom Tov.


  1. Shmos 20:9, D’varim 5:13
  2. Vayikra 23:7
  3. We consider it to be right after tzeis hakochavim.
  4. The eruv should consist of one cooked and one baked food. Each food type should be a minimum of a kezayis (an average egg). A blessing and statement are recited as these foods are set aside before Yom Tov. By setting aside this food for use on Shabbos we are in essence saying that we have some food prepared for Shabbos. Therefore, that which we cook on Yom Tov for Shabbos is only to add to this mix of prepared food for Shabbos. In addition, it is best to cook early on a Friday Yom Tov, so that the food for Shabbos is ready on Yom Tov. In essence you are also saying that the food is for Yom Tov, and if you would have visitors on Friday this food could be served to them.
  5. Please note that this may nullify a warranty.
  6. Check the appliance section of our website at www.star-k.org/appliances, or contact our office at 410-484-4110 to determine if your model has the delay.
  7. Please be aware that some companies advertise their ovens as having a Sabbath mode, when in actuality the only feature that the oven has is the 12-hour cut-off override. If it does encompass more than the 12-hour cut-off override, check to make sure there is a competent halachic authority behind the Sabbath mode to endorse it.
  8. On Shabbos, while the oven is operating, the door may be opened once and all the food removed; the door may then be closed. For further information about oven usage on Shabbos, see Oven Kashrus: For Shabbos Use on our website.