When is a Minhag no longer a Minhag?

Question

It can be all too easy for people to underestimate the halachic significance of minhagim (traditions/customs). While there are, as I understand it, a variety of halachic issues/differences of opinions, when all is said and done minhagim can and do become halachiclly binding in certain circumstances.

There are certain minhagim, however, which are mentioned in the Gemara as [at least practically speaking] universal, but today are not observed by significant communities of observant Jews and have not been for generations.

It would seem to me that while it may not be permitted to discontinue a certain minhag there comes a point that "bediavad" (after the fact) is can no longer be considered "customary" to observe a certain practice.

Are there any sources which explicitly discuss the status of discontinued minhagim and whether there comes a point when they loose their status as halachicly binding and if there is any mitzvah to re-establish a kosher minhag which lost its status as halachicly binding, whether as an individual or a community?

Answer 1

The question where the custom simply fell into disuse is an interesting one. In theory, even a Rabbinic enactment can be voided if it falls into complete disuse (though this may require a Sanhedrin). See Rambam Hilchos Mamrim:

ב,יא [ו] הרי שגזרו בית דין גזירה, ודימו שרוב הציבור יכולין לעמוד בה, ואחר שגזרו אותה, פיקפקו העם בה ולא פשטה ברוב הציבור--הרי זו בטילה, ואינן רשאין לכוף את העם ללכת בה.‏

ב,יב [ז] גזרו ודימו שפשטה בכל ישראל, ועמד הדבר כן שנים רבות, ולאחר זמן מרובה עמד בית דין אחר, ובדק בכל ישראל וראה שאין אותה הגזירה פושטת בכל ישראל--יש לו רשות לבטלה; ואפילו היה פחות מאותו בית דין הראשון בחכמה ובמניין, יש לו לבטל. [ח] וכל בית דין שהתיר שני דברים, אל ימהר להתיר דבר שלישי.‏

I'm sure there are cases discussed regarding customs, but none coming to mind at the moment.

You'll also occasionally see customs developed that rabbis strongly felt were wrong, and successfully suppressed (abrogated?). That's a different category.

But here's an easy case: what happens to local customs when a community relocates? The Chavos Yair was asked regarding a Jewish community that had certain customs (certain additional fast days; certain foods that normally don't require a hechsher, but in this town did). Due to the latest war (probably involving this guy), the people scattered and fled to other towns. Now that the war is over, if these citizens all returned to the original town, would the customs still be in effect?

Rabbi Bachrach replied that if in fact everyone had fled the town "for good", then its old customs would have been voided, even if people later returned there. However in this case, the state of the world was to go through a war every so often, and life went on. The people hadn't fled the city for good, they just temporarily evacuated it (even leaving the Torah scroll hidden so they could return to it). So the town customs remain in force.

(Citing this, Rabbi Moshe Feinstein observes simply that when the Jews left Poland around World War II, they left for good.)