In many communities, there is a Minhag of doing Kapparot in the eve of Yom Kippur, what is the best way to do the Kapparot, slaughtering a chicken or with money for charity?

First of all, we need to clarify that there is no Mitsva in the Tora to perform the Kapparot or any kind of animal sacrifice on the eve of Yom Kippur. In the days after the Bet HaMiqdash, as Maimonides explains, “en sham el-la teshuba,” there is nothing else but Teshuba to atone for our sins. Teshuba is a serious mental and emotional process of retrospection, which consists of the admission and confession of our flaws and bad habits, ultimately leading us to improve our behavior.

Kapparot is a practice that was initiated by the common people—not by the rabbis—at the time of the Geonim (800-1000 CE). The Kappara made with a live animal is supposed to help inspire our Teshuba. By witnessing the Shehita (slaughtering) of the chicken, we realize the extreme fragility of our lives, prompting us to do Teshuba and reflect on our own mortality. This is, by the way, the frequent explanation for the effect that the qorban, in the times of the Bet haMiqdash, had on the sinner’s consciousness.

However, soon after the custom of Kapparot became more popular, some prominent Rabbis like Ramban (Nahmanides) raised their voices against this practice. Maran Rabbi Yosef Caro (1488-1575), the author of the Shulhan Arukh, the supreme Code of Law for all Jews, explicitly disapproved of the practice of Kapparot with chickens on the eve of Yom Kippur, and he used very harsh terms. In the first edition of the Shulhan ‘Arukh (Venice 1565), it is written in the title of siman 605, where Rabbi Yosef Caro discusses Kapparot: מנהג כפרות בערב יום כפור מנהג של שטות הוא. “The custom of Kapparot on the eve of Yom Kippur is a foolish custom.” In later editions, the editors erased the last line (see the original edition of the Shulhan ‘Arukh here).

Why such opposition to the Kapparot?

First, as Nahmanides said: mishum darke haemori—”because it is similar to the practice of idol worshipers.” (Even today, many cults like Macumba, Vodoo, etc., use a small chicken as a sacrifice to their deities. You can Google, for example, “Eshu” or “Elleggua,” major idol-warriors of Santeria, who must be worshipped by sacrificing a small chicken).

Second, the fact that the Kappara performance resembles the Korbanot performance made many rabbis very concerned because slaughtering an animal as a sacrifice outside the Bet haMiqdash (haqrabat hutz) is a serious Biblical transgression. For this reason, many rabbis in the past forbade the consumption of the chicken that was slaughtered in this fashion (or intention) of a qorban. The Rishba, while still opposed to Kapparot with chickens, allowed eating the chicken, which was usually given to the poor, because it is not one of the animals that were offered as sacrifices in the Bet haMiqdash.

Third, since so many people want to do Kapparot on the eve of Yom Kippur, the Shehita might not be done with enough care and attention in terms of checking the knives and other ritual details. This is the point brought by Rabbi Obadia Yosef z”l (who in the past supported the Kapparot) to favor the performance of Kapparot with Tsedaqa (see this).

There is yet another problem, which should be of great concern when considering doing chicken Kapparot. Because of the great demand and the short time to slaughter so many animals, the chickens are too often mistreated in the process, left for days in cages without food or water. This is a serious transgression of an explicit Biblical prohibition instructing us to treat animals with respect and avoid unnecessary suffering (tsa’ar ba’ale hayim). The new Ashkenazi Chief Rabbi of Israel, Rabbi David Lau, addressed this issue last year (see here).

Lastly, if the person who does the Kappara would give the slaughtered chicken directly to a poor person, as was done in the past, then we could view this Kappara as a form of Tsedaqa. But people who perform the Kapparot often take seriously the idea of transferring their sins into the chicken, and therefore, neither they nor needy people would eat those chickens “full of sins.” Many of these chickens are not eaten but wasted. If one kills an animal unnecessarily (not to be eaten), one transgresses another explicit Biblical prohibition: bal tashchit, i.e., unnecessary waste of the blessings, in this case, an animal’s life, that God granted us.

In conclusion, the best way to do Kapparot is by giving Tsedaqa (charity for needy people). In this case, none of the above-mentioned problems would apply, and in addition, before Yom Kippur begins, you will be fulfilling the beautiful Biblical commandment of charity. This is a Mitsva with no negative side effects. On the contrary, Tsedaqa was regarded as the most important Mitsvat ‘ase, as Maimonides writes: “We have to care about the Mitsva of Tsedaqa more than [we care about] any other positive commandment” (MT, Matanot ‘Aniyim 10:1). Tsedaqa brings great zekhut (merit) to the giver and great relief to the recipient—וצדקה תציל ממות.

See this video where Rabbi Shelomo Aviner, Rosh Yeshibat Ateret Cohanim, explains the ways of doing Kapparot and mentions, among other things, that Rabbi Kaddouri z”l and Rabbi Shlomo Zalman Auerbach z”l did Kapparot with Tsedaqa instead of chicken (here).