In honor of my younger son Hillel’s bar mitzvah, we explored a topic regarding which Hillel is quite passionate: the great debate concerning opening containers on Shabbat and Yom Tov. There is a rich discussion about this issue regarding which Hillel and I wish to share our thoughts. Hillel, who believes that the lenient view is most compelling, is quite the competitor, from the ball fields to the chessboard to (most important) practical Halacha. Therefore, he will be making a strong case supporting the lenient view.
Last week we began by laying the groundwork for the 20th and 21st-century debates from the Gemara and Rishonim to the Shulchan Aruch and its commentaries and through the late 19th-century halachic codifiers.
The mainstream view permits opening only poor-quality containers (mustiki) on Shabbat and Yom Tov. However, a significant view permits opening even standard-quality and -sized containers on these holy days. The latter view may be relied upon as an adjunct to a lenient view.
Now that Hillel and I have set the groundwork for the modern-day debate about opening containers, we are ready to present the opinions of the great modern-day poskim on this topic.
Cans: Four Approaches
Poskim have debated the issue of opening cans on Shabbat and Yom Tov for many decades. Four basic approaches have emerged. First, the Tehillah LeDavid (314:12) believes that cans constitute sturdy vessels, which are forbidden (on a rabbinic level) to open, lest he fashion a proper opening.
On the other hand, many poskim (Kaf Hachaim 314:38; Rav Shlomo Zalman Auerbach, cited in Shmirat Shabbat Kehilchata 9: footnote 10; Rav Ovadia Yosef, Teshuvot Yechave Daat 2:42; Rav Yosef Dov Soloveitchik, quoted by Rav Yosef Adler) regard cans as a mustiki, since almost everyone discards them after use. We stress that even these authorities prohibit opening a can if one intends to use it for storage after removing its contents. Moreover, these authorities urge accommodating the stricter opinion and opening cans before Shabbat.
Additional support for the many poskim who reject the Tehilla L’David’s approach is the many Rishonim and the Vilna Gaon who rule that one may break open even a proper vessel to procure the food contained within it. Nonetheless, even those who adopt the lenient view, beginning with the Kaf HaChaim, write that it is preferable to avoid the question altogether and open cans before Shabbat.
The Chazon Ish (O.C. 51:11) adopts a most creative position regarding cans. He believes that a sealed can is not the halachic equivalent of a barrel, which is forbidden to open only on a rabbinic level. He argues that a can, unlike a barrel, does not have the halachic status of a vessel (kli). Therefore, the Chazon Ish asserts that when one opens a can he “transforms a [functionless] sealed item into a functional kli.” Hence, the Chazon Ish believes that opening a sealed can violates the biblical prohibition of binyan (building) on Shabbat. Rav Shlomo Zalman Auerbach (Shmirat Shabbat Kehilchata 9: footnote 10) argues that binyan occurs when sealing the cans in the factory. It seems counterintuitive to Rav Auerbach that sealing the cans constitutes an act of soter when one’s intention in sealing the cans is solely to facilitate shipment and preserve the long-term integrity of the food contents.
Most poskim do not subscribe to the Chazon Ish’s view. It is difficult to distinguish between a sealed barrel, which the Gemara permits opening for food, and opening a metal can, which the Chazon Ish classifies as boneh.
Rav Moshe Feinstein (Teshuvot Igrot Moshe O.C. 1:122) wrote a lengthy responsum on this topic. (Interestingly, Rav Moshe wrote this teshuva in 1935 when the Soviet police placed him under house arrest because he served as a community rabbi. Ironically, this teshuva explores this issue in great depth, likely due to Rav Moshe’s extra time to concentrate on his writing because of the Soviet authorities’ limitation on his activities outside the home. Similarly, Shemot 1:12 records that the more they try to hurt us, the more we flourish).
Rav Moshe writes that it is theoretically permissible to open cans that people customarily discard after emptying them. He believes that opening these cans is analogous to cracking open a nut or peeling a banana (see Shulchan Aruch O.C.314:8). Rav Moshe argues that even Tosafot, Rosh, and Shulchan Aruch would permit opening this type of can since there is no concern for fashioning an opening. However, Rav Moshe writes that it is forbidden to open those cans that some people use after emptying their contents. Regarding these cans, there is concern that one will create a functional opening. Rav Moshe also believes that when one intends to use a can after emptying its food contents, he establishes a kli. Rav Moshe believes that the can is not a kli because people intend to use it only once. Only when one wants to reuse a can does it attain the status of a kli.
Rav Moshe writes that in practice one should not even open cans that people customarily discard. He expresses concern that unlearned people will be unable to distinguish between cans that we may open and those we may not. He cites as precedent Shabbat 139 where the Gemara forbids certain permissible activities for communities where the people are not scholars. Rav Moshe notes the lack of Torah scholarship and the prevalence of chillul Shabbat in our generation. Hence, he refrains from issuing a lenient ruling that he feels will ultimately lead to chillul Shabbat.
Nearly one hundred years after Rav Moshe composed this teshuva, circumstances have changed dramatically. It is far less common to reuse cans after emptying their contents, and learned Jews are dramatically more common, baruch Hashem.
Conclusion
The consensus view follows the straightforward approach to permit the opening of food cans on Shabbat. Nonetheless, poskim agree that the best policy is to survey the situation at home on Erev Shabbat and open any cans that one might need on Shabbat. If one did not do so, Rav Yitzchak Yosef (Yalkut Yosef Orach Chaim 314:24) rules that baseline halacha permits opening the cans. However, he adds that it is proper to open the can on both sides to destroy the can entirely, to avoid the Chazon Ish’s stringent concern that by opening the can, one violates boneh.
Rabbi Haim Jachter is the spiritual leader of Congregation Shaarei Orah, the Sephardic Congregation of Teaneck. He also serves as a rebbe at Torah Academy of Bergen County and a dayan on the Beth Din of Elizabeth.