Waiting Between Milk & Meat
How long after must I wait between eating milk and meat? And why?
The Aish Rabbi Replies:
After eating meat (or fowl), you must wait 6 hours before eating any dairy products. (This is measured from the last bite of meat, even if the meal continued longer.)
The issue of waiting between meat and dairy comes from the Talmud (Chulin 105a), and the reason is discussed by the two great Torah commentators:
Maimonides says that we are concerned about strands of meat being stuck between the teeth. After 6 hours, however, that meat has undergone a sufficient enough process of "digestion" whereby it becomes "pareve." (Laws of Forbidden Foods 9:28)
Rashi, on the other hand, says the 6-hour wait is based on the fatty nature of meat. Not only does meat leave a residue in one's mouth and throat, but when meat is in your stomach, the fatty gasses can escape (through burping, for instance) and cause a "meaty flavor" in one's mouth. If a person would eat dairy during this time, they would have the combined flavor of milk and meat in their mouth, which is prohibited. (see Rashi – Chulin 105a)
In cases of a health concern, or for children under the age of six, a one-hour wait is sufficient.
By the way, these laws due not apply in the reverse case: After eating dairy, there is no necessity to wait six hours before eating meat. It would suffice to wash the hands and mouth. (Some are stringent to wait following hard cheese.)
To learn more, read "The Laws of Kashrus," by Rabbi Binyomin Forst (artscroll.com)