By Rabbi Chaim Hillel Raskin
There are three possible melachos involved in opening a can:
- (1-2) Binyan, Stira: Chazal say that in some instances the melachos of building and destroying apply to vessels.1 Some rishonim limit this to stable vessels made for long-term use, but not to flimsy containers.2 Others limit the prohibition to when the vessel is extremely large that it can contain 40 se’ah (approx. 387 liter).3 Both opinions are quoted in halacha, and thus one may only break a small-sized flimsy vessel.4
- (3) Makeh b’patish: Fashioning a “nice opening” to a vessel constitutes completing it, which is prohibited. This prohibition only stands when one intends to fashion a nice opening (i.e. for repeated use), otherwise it cannot be said to be “completing a vessel.”
- Regarding a can, some poskim say that since it is sturdy and holds its contents for a long time, opening it is a prohibition of stira, destroying.5 However, many poskim suggest that since food cans are disposable and not intended for reuse they are considered “flimsy” and there is no destroying.6 Additionally, since one has no intention of reusing it, if he doesn’t care to create a “nice opening” and there is no makeh b’patish either.7 (Regarding a sturdy container, creating any opening is forbidden, as a concern that one will intend to create a nice opening.)
- Since on occasion some people will reuse a can, some contemporary poskim insist that for the can to be truly considered disposable it is necessary empty out all its contents upon opening it. This demonstrates that the can is like a “wrapper” for the food, and not a vessel to be used.8
- Some acharonim9 claim that the problem with opening is not the demolition of the can (stira), but the creation of a container (binyan). To circumvent this problem, some recommend puncturing a hole in the bottom of the can before opening the top. Thus he did not create a usable vessel.10
- Practically, one should endeavor to open all such cans before Shabbos. If not, one may open the can and spill out the contents right away. One who wishes to be scrupulous should puncture a hole in the bottom side before opening the can.
Reprinted with permission from Lmaan Yishmeu – a project of Merkaz Anash. To see more articles visit Merkazanash.com
- ראה שבת קכב ע”ב ועירובין ל”ד ע”ב.
- רא”ש עירובין פ”ד ס”ה.
- ר”ן שבת ס”א ע”ב ד”ה שובר.
- שוע”ר או”ח סי’ שי”ד ס”א.
- וראה תהל”ד סי’ שי”ד ס”ק י”ב, וממלכת כהנים סי’ כ”ד שהכריעו לאסור
- כף החיים סי’ שי”ד סקל”ח.
- מנחת שלמה ח”ב סי’ ל”ב. ראה ספר להלכה ח”ב עמ’ רל”ד.
- ראה קצוה”ש סי’ קי”ט בדה”ש סק”ז (וראה קצוה”ש שם סי”א).
- ראה בארוכה ארחות שבת פי”ב הע’ ו’ שדן בזה באריכות.
- ראה שש”כ פ”ט אות ג’ וראה מנח”י ח”ד סי’ פ”ב שרעיון זה מועיל גם לזה שמוכיח שיש לכלי דין מוסתקי.
