The “Sabbath Mode”


Mr. Jonah Ottensoser, Star-K Engineering Consultant

Appliance manufacturers, with the aid of modern technology have designed kitchen appliances to be safer, more efficient and incorporate various features to enhance operation. However, the incorporation of this technology may pose a challenge to their proper use on Shabbos and Yom Tov.

In 1997, a historic technological project was launched between a major appliance manufacturer and a kosher certification agency. Whirlpool Corporation (manufacturers of KitchenAid) approached the Star-K to help them modify their ovens so they could be used on Shabbos and Yom Tov. Prior to that time many of their appliances did not conform to halachic guidelines for use on Shabbos or Yom Tov. After making adjustments, a successful mode was developed. Whirlpool called this “the Sabbath Mode” and was awarded a patent in 1998 for this concept.

Star-K certification on appliances falls into two categories. The first, Sabbath Mode, includes models that have unique software/hardware designed into them that specifically address our concerns. The second category, Sabbath Compliant, includes models that the manufacturer wanted us to assess for use by the observant Jew. The intention was to help the consumer avoid the unwanted surprise of not being able to use their expensive purchase on Shabbos and Yom Tov. Details of manufacturers in both these categories, listed by company along with the specific model numbers, can be found in our appliance section.


Category One – Sabbath Mode

Note: The Sabbath mode does not allow us to turn these appliances on or off on the Sabbath. The Sabbath mode also does not allow us to use these appliances completely at will on Shabbos or Yom Tov. Rather, it enables us to use these appliances within the guidelines of halacha as delineated in the letters of certification (available from the Star-K office) or as posted in our appliance section.

Ovens with the Sabbath mode on will not shut off after twelve hours of continuous operation. In many cases this mode will prevent the oven light from going on/off as the door is opened/closed. In some models, however, the bulb must be unscrewed or the light left on for the entire period. No lights, digits, solenoids, fans, icons, tones or displays will be activated/modified in the normal operation of the oven.

For these Sabbath mode models, the set temperature can be raised or lowered on Yom Tov (but not on Shabbos) for cooking purposes at any time, because there is a built-in delay between the request for temperature change and its actual implementation.

Category Two – Sabbath Compliant

Ovens certified as Sabbath compliant have the same basic features as those with the Sabbath mode, except no delay is built into the set temperature change process. Therefore, the temperature cannot be changed on Yom Tov. On some models, adjustment of the set temperature may still be possible on Yom Tov. These models do not have a digital temperature readout. They have an indicator light that cycles on/off as power is on/off to the heating elements. One can raise the temperature when the light is on and lower it when it is off. For other Sabbath compliant models which do not have a cycling indicator light, the set temperature chosen before Yom Tov cannot be adjusted on Yom Tov. Our appliance section has details about specific models.

Timed Bake

Many ovens have a timed bake feature that permits one to have the oven go off after a fixed period of time. However, after the time is up, many models chime indefinitely or have an icon or light that is cancelled when the door is first opened. Our appliance section lists those models that have timed bake without these drawbacks when in Sabbath mode.

Warming Drawers

Warming drawers should be treated as standard ovens since they present the same issues. They are thermostatically controlled and their lowest temperature is often above 115°F. As is the case with a standard oven, all food must be placed in the warming drawer before the start of Shabbos.

Power Failures

For safety reasons, most ovens will not recover from a power failure in the ON condition. Some exceptions are noted in our appliance section.


Not to be left out in the cold, refrigerators have also succumbed to the incorporation of modern technology. In addition, old issues such as when to open the refrigerator door on Shabbos, and what to do about heating elements that turn on to defrost the coils, remain to be solved. The Star-K has developed a set of requirements that use modern technology to alleviate these problems.

Refrigerators certified by the Star-K incorporate the technology that solves these issues. After entering the certified mode (called either Sabbath or Holiday mode), the consumer does not have to worry about lights, digits, icons, tones, alarms, solenoids or fans being activated/deactivated when opening or closing the door. A built-in delay prevents the compressor from turning on immediately after the door is opened. The defrost cycle operates solely on clock time without any feedback from consumer usage of the refrigerator. (Current technology is introducing control of the defrost cycle by counting the number and length of door openings which may present a halachic problem.) Finally the ice and coldwater systems will be turned off since they invariably use electrical solenoids and motors to operate. (After a power failure, units will return to the certified mode.)

This article is merely an overview of the application of modern technology to appliances and how it affects the Orthodox Jewish consumer. For certified models, and guidelines for their proper usage, please check our appliance section.