Kosher Milk

Background

1. It is rabbinically forbidden to drink milk that was milked from a cow by a non-Jew without a Jew watching out of a concern that he might mix in milk from a non-kosher animal
2. In a country where there is a law that makes it illegal to mix milk from other animals into cow milk and sell it as milk, some poskim say that it is permitted to drink kosher milk which isn't chalav yisrael. Other poskim hold that it is forbidden and so it is proper to be strict except for someone who is sick or a baby. Those who live in the diaspora and it is difficult to be strict on this, have what to rely upon if they are lenient.

Powdered Milk

1. According to some poskim, even powdered milk is included in the rabbinic prohibition of drinking milk when the milking process wasn't supervised by a Jew throughout.

Further Reading

General

• Butter (OU Kosher) - a discussion of modern butter making and its kashrut challenges
• Milk from a Possibly Treif Cow (OU Kosher)
• Is our Milk Kosher? - A Halachipedia article on the Kashrut of milk nowadays

Milk Products

• What In the World is Whey? - (OU Daf HaKashrus [Issue 10, Shavuos 5776])
• THE KASHRUS OF BUTTER (OU Daf HaKashrus [Issue 18, Shavuos 5778])
• EATING HER CURDS? NO WAY (Star-K Kashrus Kurrents), regarding the making of cheese, whey, and casein products
• Kashrus of Milk (Rav Tzvi Sobolofsky)

Chalav Yisrael

• Chalav Yisroel (OUKosher)
• Rav Moshe zt”l’s Heter of Cholov Stam Revisited (OUKosher)
• CHOLOV YISROEL: DOES A NESHAMA GOOD (Star-K)
• Halachically Speaking: Cholov Stam and Cholov Yisroel
• Chalav Yisrael Part I (Rav Chaim Jachter)
• Cows, Camels, and Chalav Yisrael (Rav Yona Reiss)