If a Torah observant Jew eats Chalav Akum, may another Jew who only eats Chalav Yisrael accept the invitation to eat at their house? Assuming the kitchen is kosher in every other respect, does Chalav Akum pose a barrier to eat at the friend’s house? Does Chalav Akum change the status of pots and pans for Chalav Israel eaters (may one eat cooked food if it excludes milk in the dish or if milk is bitul b’shishim)? Finally, can eating Chalav Akum affect the trustworthiness of a Jew (i.e., to be a witness for a wedding, testify that a certain food without an hechsher is kosher, etc.)? Thank you for your time and your greatly respected wisdom.
Shalom, From your question it is clear that you are well aware of the argument between the Rabbis about the acceptability of government supervision of milk. Many Jews, and kashrut organizations, rely on Rabbinic opinions that allow the use of such milk, whilst many Jews refrain. In order to answer your question one first must reach an understanding as to their view of chalav akum today. (I assume you are referring to milk from countries where the local kashrut authorities rule that the local milk is under enough government supervision as to be considered kosher by the lenient opinions, such as Rav Moshe Feinstein zt"l and the Chazon Ish zt"l, and not classic chalav akum, from a Bedouin trader in the desert for example). If one holds that the lenient halachic opinions are totally baseless, then the answer is quite simple - a kitchen that freely uses such milk is not kosher on the dairy side (see Shulchan Aruch, Rema, Y.D. 115,1). Though there is room for a discussion about whether post-facto such milk is nullified by 60 times its size, or just a majority (see Darchay Tshuvay ibid,19), and whether non-milk food may be kosher after the fact - one must certainly refrain from accepting an invitation to eat in such a situation. If one holds such an opinion then one should discuss with a Rabbi what to do in cases of need, or when not eating at such a house may cause strife (just as one should discuss such an issue if the friend's house has other problematic kashrut issues, such as non-kosher wines or cheeses etc.). However, many Rabbis rule that one may certainly rely on the lenient opinions about chalav akum today, at least when it comes to the question of eating non milk products on such dishes. This is because one has several halachic doubts that join together to create a lenient ruling. See Rav Ovadya Yosef's Yechavay Daat, volume 4, 42 where he rules leniently on this issue in times of need. Other Rabbis rule leniently at all times. In my humble opinion, one may rely on these rulings to eat non-milk products in such a house, even if you personally refrain from eating chalav akum normally. A Jew who relies on the rulings of great Torah sages and drinks standard government-supervised chalav akum today is certainly a kosher Jew and acceptable as a witness. Many fine and G-d-fearing Jews and Torah scholars eat such foods and one should relate to them with all the respect and honor shown to all upright religious Jews. Blessings, D. Sperling.