Combating what is disliked
In addition to changes being made in Torah laws to add stringencies, to remove offensive material from the Torah text, changes were introduced into Judaism to combat the views of non-Jews and Jews who do not practice what the rabbis consider correct, and to disassociate Jews from them. The law about mixing meat and milk is an example. The Torah repeated the prohibition “You should not boil a kid in its mother’s milk” in Exodus 23:19, 34:26, and Deuteronomy 14:21 using the same language in the three sources.
Maimonides explains in his Guide of the Perplexed 3:48. “Meat boiled in milk is undoubtedly gross food, and makes one overfull; but I think that most probably it is also prohibited because it is somehow connected with idolatry, forming perhaps part of the service or being used on some festival of the heathen. I find a support for this view in the circumstance that the Law mentions the prohibition twice after the commandment given concerning the festivals ‘Three times in the year all thy males shall appear before the Lord God’ (Exod. xxiii. 17, and xxxiv. 73), as if to say, ‘When you come before me on your festivals, do not seethe your food in the manner as the heathen used to do.’ This I consider as the best reason for the prohibition.” While it was clear to Maimonides that the Torah was only prohibiting the involvement in a pagan religious practice, the rabbis changed the law to a prohibition against eating meat together with dairy products.
Tzvi H. Adams in a comprehensive, very learned article “Waiting Six Hours for Dairy- A Rabbanite Response to Qaraism,” which was posted on the website Seforim Blog, informs readers how the rabbinic expansion of the Torah rule, which originally grew into a mandate that only prohibited eating the two foods together, later developed into a law to wait six hour between eating meat and dairy products as an opposition to Karaites (also spelt Qaraites).
Tzvi H. Adams tells readers that “Scholars have noted that many minhagim [customs] began as a response to the Qaraite movement. For example, the recital of bame madlikim on Friday evening after davening was started in the times of the Gaonim to reinforce the rabbinic stance on having fire prepared before Shabbos, in opposition to the Qaraite view that no fire may be present in one’s home on Shabbos. There is evidence that the reading of Pirkei Avos on Shabbos afternoon, which began in Gaonic times, was to emphasize to the Jewish masses that the Oral Law was passed down since Moshe Rabbeinu as stated in the first Mishna of Pirkei Avos.” The Karaites denied the rabbinic teaching that God revealed both written and oral Torahs, and that many of the rabbinic teachings were divine commands contained in the oral Torah, which like the written Torah was promulgated by God.
Adams points out that the Karaites interpreted the law about boiling a kid in its mother’s milk literally as Maimonides did, and insisted that the law to separate meat and dairy products was only a rabbinical enactment that they did not have to accept.
The Karaites are a movement within Judaism that began around the eighth century CE. When the Karaite movement began, its adherents refrained from eating meat and drinking wine as an ascetic mourning for the destruction of the temple in 70 CE. Thus, for the first couple of centuries of its existence, because they did not eat meat, no issue arose concerning the rabbinic interpretation to the three verses. However, after a couple of centuries, the Karaites relaxed their mourning restriction, and because of their literal reading of the three verses had no hesitations against eating meat and dairy together.
“In the middle of the tenth century, Qaraite lawmakers gradually adopted a more lenient worldly approach, allowing meat consumption. With authorization to eat meat, Qaraites did so with no compunctions about preparing the meat with dairy. This Qaraite breach of the Oral Law earned them the nickname ‘the eaters of meat with milk.’ This transgression of the Qaraites became symbolic of the entire conflict between the Rabbanite and Qaraite camps. Throughout this period, the two camps were very connected socially, politically, and economically. There were Rabbanite-Qaraite marriages, joint business ventures, and joint communities. The lines between the two camps were not as distinct as we may imagine. At some point in the early eleventh century, the Rabbanite rishonim [early rabbis] devised a way to create greater division and social split between the two camps. Choosing the very topic which represented the heart of the schism, they [for the first time] reinterpreted Talmudic passages in a manner which requires waiting six hours between eating red meat and dairy products, further separating the Rabbinites from the Qaraites both halachically and socially.”
Adams stresses that this six-hour rabbinic enactment only required separating meat and dairy products. But not fowl; one could eat chicken together with cheese. “However, Rabbinites and Qaraites could still enjoy a poultry-dairy meal together during community gatherings or business meetings.” Adams reveals that “Maimonides was the first to attempt to further widen the gap [between Jews who accepted rabbinic teachings and the Karaites who denied their validity] by including poultry in the six-hour wait category. He was quickly attacked by other Talmudists such as Nachmanides and R. Aaron HaLevi for contradicting the Talmud’s legal allowance. However, in time even Maimonides’ expansion” was accepted by Judaism.
In short, we see a three tiered development of changes in biblical law. First, the rabbis interpreted a scriptural rule to disassociate Jews from pagan worship by expanding the law not to boil a kid in its mother’s milk to prohibiting eating meat together with dairy products. This rabbinic act enacted to distance Jews from non-Jews is similar to the rabbinic command not to eat non-Jewish bread and not drink non-Jewish milk and wine even though these foods may be kosher.
Second, in the middle of the eleventh century, the rabbinic meat-milk prohibition was expanded by Rabbenu Chananel to require a separation of six hours between consuming meat and dairy. This was enacted to separate rabbinically-oriented Jews who accepted the concept and binding force of the oral Torah from Karaites who did not.
Third, since Maimonides saw that rabbinic Jews ate poultry together with dairy at Karaite feasts, he expanded the law further to include not consuming poultry with dairy to assure that the two groups would not overly socialize with the result of rabbinical Jews being drawn to and accepting Karaite views.
 Translation of M. Friedlander in Guide for the Perplexed.
 Many Orthodox Jews today, but not all, ceased avoiding eating non-Jewish bread and drinking non-Jewish milk, but retain the practice of refraining from non-Jewish wine. It is possible that the latter stringency was retained because it developed from another more ancient rabbinic command while the milk and bread rules do not. There was an earlier rabbinic mandate prohibiting drinking pagan wine because the wine may have been sanctified to use for pagan idol worship. Once idol worship ceased, there was no need for this command. It was replaced by the current decree to abstain from non-Jewish wine simply to separate Jews from non-Jews.
Non-Jewish wine that had merely been touched by a non-Jew is not prohibited. Three actions have to take place: touch and movement by a non-Jew when the bottle was already opened. See Shulchan Arukh Yoreh Deah 124:11. The law about closed bottles allowed non-Jews to ship wine. Since this law was an expansion of the law prohibiting the use of wine used by pagans at their idol sanctuaries, and since the pagans did not use whiskey and beer in their ceremony, it seems that this was why the new law did not include liquors and beer. The rabbis only applied this rule to bona fide wine, not wine that was pasteurized or cooked (called yayin mevushal) because boiled wine was not used for idol worship. They also allowed non-Jews to carry an open bottle of wine if the bottle was wrapped in a cloth. Since the prohibition does not include whiskeys and beers and since it has other ways of avoiding the prohibition, it seems that the current rule which is designed only to disassociate Jews and non-Jews is only symbolic, and it is therefore not surprising that just as many Orthodox Jews ceased following the laws concerning non-Jewish bread and milk, the Conservative Movement also ceased following the rule about non-Jewish wine.
Since boiled wine was not considered real wine and since only non-boiled wine was used in the temple service, Rabbi J. B. Soloveitchik suggested that we use non-boiled wine for Kiddush on Shabbat.
 He was born in 990.
 The rabbis allowed eating meat after dairy if one cleaned one’s mouth.