Halakhah for Shabbat 22:3
שׁוֹבֵר אָדָם אֶת הֶחָבִית לֶאֱכֹל הֵימֶנָּה גְרוֹגָרוֹת, וּבִלְבַד שֶׁלֹּא יִתְכַּוֵּן לַעֲשׂוֹת כְּלִי. וְאֵין נוֹקְבִים מְגוּפָה שֶׁל חָבִית, דִּבְרֵי רַבִּי יְהוּדָה. וַחֲכָמִים מַתִּירִין. וְלֹא יִקְּבֶנָּה מִצִּדָּהּ. וְאִם הָיְתָה נְקוּבָה, לֹא יִתֵּן עָלֶיהָ שַׁעֲוָה, מִפְּנֵי שֶׁהוּא מְמָרֵחַ. אָמַר רַבִּי יְהוּדָה, מַעֲשֶׂה בָא לִפְנֵי רַבָּן יוֹחָנָן בֶּן זַכַּאי בַּעֲרָב, וְאָמַר, חוֹשְׁשָׁנִי לוֹ מֵחַטָּאת:
It is permitted to break a jug (on Shabbath), [this being "mekalkel" (damaging)] in order to eat figs from it, so long as he not intend to make a vessel [i.e., to make a nice opening for it]. And it is forbidden to puncture a stopper of a (wine jug) [i.e., the stopper which is sealed onto the mouth of the jug; but he removes it all, for puncturing the stopper is (considered) fashioning an opening.] These are the words of R. Yehudah. R. Yossi permits it, [this not being the conventional opening. The halachah is in accordance with R. Yossi.] And he may not puncture it from its side. [That is, R. Yossi permits puncturing it only from the top, at the head of the stopper, it not being customary to fashion an opening there, but rather to remove the entire stopper. But, on the side, sometimes one does puncture the side of the stopper to make an opening (not wanting to open it on top so that pebbles or sand not fall into the wine.)] And if it were punctured, he is not permitted to place wax upon it, this being memareach ("smearing") [forbidden by reason of memachek ("erasing")]. R. Yehudah said: Such an instance [placing wax, etc.] came before R. Yochanan b. Zakkai in Arav, and he said: "I fear that he might be liable for a sin-offering" [if he smeared wax to fasten it to the walls of the vessel around the hole.]