There is a well-known requirement to wait a certain amount of time between eating meat and dairy products.[1] The most widespread custom is to wait six full hours.[2] German Jews generally wait three hours,[3] and Dutch Jews generally wait one hour.[4] There are other customs, as well. The source for the different waiting times between meat and dairy is generally taken from the amount of time, in earlier generations, that passed between one meal and the next.[5] The waiting period is calculated from the time that one actually ceases eating meat even if one continues to eat other foods during the meal.[6] One must always recite Birkat Hamazon (or other bracha achrona, as appropriate) before eating dairy, no matter how much time has passed.[7]

There are those who rule that the custom of waiting “six hours” between meat and dairy does not require six full hours, but rather, a little more than five and a half hours. Some even rule that it is sufficient to merely wait "into the sixth hour."[8] Most authorities, however, insist that the custom requires one to wait six full hours between meat and dairy.[9] There is a view that one can be lenient if one only ate poultry.[10] One who lost track of time or is otherwise unsure if six hours have passed is permitted to eat dairy if it is reasonable to assume that six hours have passed.[11]

One whose family’s custom is to wait six hours may not change to the three-hour or one-hour custom.[12] Similarly, those with no established custom should wait six full hours as it is both the ruling of the Shulchan Aruch, and the most widespread custom.[13] Rav Yosef Shalom Elyashiv was of the opinion that everyone in Israel must wait six hours between meat and dairy regardless of their ancestral custom.[14] A married woman is to follow her husband’s custom.[15]

It is interesting to note that there is an opinion that sleeping a significant amount of time after eating meat allows one to eat dairy upon awakening.[16] Indeed, the Chatam Sofer originally agreed with this approach. He later retracted his ruling, however, when he noticed that his milk would spill every time he tried drinking it after merely sleeping, and not waiting the full six hours. He took it as a sign from heaven that his view was not accepted.[17] In a variation of this custom, Rav Elyashiv holds that one who slept at least three hours after eating chicken (not meat) may eat dairy right away.[18] The halacha, however, is not in accordance with any of these views.[19]

We are required to wait between meat and dairy for two reasons. One reason is that the taste and fatty residue of meat lingers in the mouth and palate for an extended period of time.[20] The other reason is that meat often gets stuck between one’s teeth and it takes about six hours for such meat to decompose to the point that it is no longer considered to be meat.[21] The halacha is in accordance with both explanations. As such, one who vomits after a meat meal must still wait the required amount of time, as must one merely swallowed meat without chewing it.[22]

We see from the above that there is little basis for the theory that the six hour wait is in order to ensure that any meat that one ate has been fully digested.[23] Nevertheless, some suggest that the custom of Dutch Jews to wait one hour was instituted to ensure that digestion has begun, and related considerations.[24] Others suggest that the source for the one-hour custom is a passage in the Zohar that speaks of a prohibition to eat dairy and meat within one hour of each other.[25] There are other theories for the one-hour wait, as well.[26]

One who merely tastes meat, without chewing or swallowing it, is not required to wait any amount of time before eating dairy.[27] One is merely required to rinse one’s mouth before doing so.[28] One who is ill, or is otherwise required to consume dairy products frequently, need only wait one hour after eating meat.[29] Older children should be taught to wait between meat and dairy in accordance with their parents’ custom. Younger children need not be prevented from eating dairy after eating meat if they waited some amount of time, though one should seek rabbinic guidance on this issue. Indeed, children who are too young to even understand the idea of not mixing meat and dairy need not wait any amount of time between the two foods.[30] A pareve food that was cooked together with meat is considered to be meat, and the required waiting time must be observed before eating dairy.[31]

One is actually not truly required to wait any specific amount of time after eating dairy before eating meat.[32] One is simply required to cleanse one's mouth and wash one's hands.[33] One must also be sure to recite Birkat Hamazon (or other bracha achrona, as appropriate) before eating meat no matter how much time has passed.[34] Nevertheless, there is a widespread custom, based on the Zohar, to wait one hour between dairy and meat.[35] Some have the custom to wait half an hour between dairy and meat.[36] There is no waiting requirement after swallowing meat or dairy pills.[37]

[1] Chullin 105a.

[2] YD 89:1.

[3] Rabbeinu Yerucham, Issur V’heter 39; Chochmat Adam 40:12. Note: Many other German authorities rule that a full six hours is required. See: Kreisi U’pleiti, YD 89:3; Noheg K’tzon Yosef, Hilchot Seuda; Chorev vol. 4 Chapter 68.

[4] Rema, YD 89:1. See also Issur V’heter 1:4; Levush, YD 89:1.

[5]Chullin 105a; Rosh, Chullin 8:5; Rambam, Hilchot Ma'achalot Assurot 9:28; Biur Hagra, YD 89:2.

[6] Dagul Mervava, YD 89; Badei Hashulchan 89:7. See Aruch Hashulchan, YD 89:4 for an alternative view.

[7] Rema, YD 89:1; Shach, YD 89:6; Chochmat Adam 40:12; Aruch Hashulchan, YD 89: 6.

[8] Rambam, Hilchot Ma'achalot Assurot 9:28; Yabia Omer 1:4, 3:3; Nishmat Avraham, YD 89:1; Ashrei Ha’ish, YD 1:5:20.

[9] YD 89:1; Shach, YD 89:8; Taz, YD 89:2; Darkei Teshuva, YD 89:6; Badei Hashulchan 89:8.

[10] Yabia Omer, YD 1:4:13.

[11] Darkei Teshuva 89:5; Badei Hashulchan 89:9.

[12] Chochmat Adam 40:13; Aruch Hashulchan, YD 89:6.

[13] Shach, YD 89:8; Rivevot Ephraim 5:513:2.

[14] Ashrei Ha’ish, YD 1:5:20.

[15] For more on this issue see: Tashbetz 3:179; Igrot Moshe, OC 1:158; Yabia Omer, 5:37; Yesodei Yeshurun 6:239-240.

[16] Daat Kedoshim, YD 89:2; Vayaas Avraham (Tchechnov) pg. 333.

[17] Zichron L’moshe p. 65. See here: http://www.hebrewbooks.org/pdfpager.aspx?req=38601&st=&pgnum=155.

[18] Ashrei Ha’ish, YD 1:5:25; Doleh Umashke p. 258 footnote 15.

[19] Teshuvot V’hanhagot 1:431; Mishne Halachot 7:70; Beit Avi, YD 3:108; Shulchan Halevi 1:22:10.

[20] Rashi, Chullin 105a.

[21] Rambam, Hilchot Ma'achalot Assurot 9:28.

[22] Rivevot Ephraim 8:336.

[23] Kreiti Upleiti 89:3.

[24] Chochmat Adam 40:13.

[25] Biur Hagra, YD 89:6.

[26] Taz, YD 89:2.

[27] Darkei Teshuva 89:12, 22; Kaf Hachaim, YD 89:4; Badei Hashulchan 89:16.

[28] YD 89:2; Aruch Hashulchan, YD 89:5; Kaf Hachaim, YD 89:56, Badei Hashulchan 89:16.

[29] Kaf Hachaim, YD 89:7,21.

[30] For this and more on the requirement for children to wait between eating meat and dairy, see: Mishna Berura 343:3; Chelkat Yaakov 2:88,89, 3:147; Yechaveh Da'at 3:58; Yabia Omer, YD 1:4; Teshuvot V’hanhagot 1:435; Ashrei Ha’ish, YD 1:5:24.

[31] Rema, YD 89:3. A pareve food that was merely cooked in a meat pot is considered to be pareve. There is a difference of opinion, however, whether one is permitted to eat such a food together with dairy.

[32] Rambam, Hilchot Ma'achalot Assurot 9:26; YD 89:2.

[33] YD 89:2; Aruch Hashulchan, YD 89:8.

[34] Taz, YD 89:2; Shach, YD 89:6.

[35] Biur Hagra, YD 89:6; Kaf Hachaim, YD 89:30; Teshuvot V'hanhagot 2:390.

[36] Shraga Hameir 7:105:3.

[37] Igrot Moshe, YD 2:26; Rivevot Ephraim 5:517.