The Rebbe's guidance on kashrus — keeping a kosher home, Cholov Yisrael, and communal kosher supervision:
Why it matters. Non-kosher food harms both body and soul, even if the effects appear only later (IK 2910), and high standards of kashrus shape children's character (IK 6611). Strengthening kashrus affects both physical and spiritual life (IK 9099). Kashrus and Shabbos are both fundamental and neither may be traded for the other (IK 7800). A Jewish home is built on family purity, a kosher kitchen and Shabbos (IK 1705, 2319); when not everything can be done at once, these come first (IK 10972).
Daily practice. Check the kashrus of food when visiting others (IK 6476). Keep kashrus even in hard settings, such as a senior home or aboard ship (IK 1181, 6266). Address kashrus questions at work thoughtfully, without excessive stringency (IK 668). Cholov Yisrael should be maintained, and bringing it to a community is worth persistent effort (IK 3888, 7286). Investigate kashrus questions locally, such as the coatings of pills (IK 7352).
Communal kashrus. Kosher food, like education, requires careful supervision (IK 1414), which rests on rabbinic leadership (IK 8377). Uphold high standards in communal kashrus (IK 6017), stay vigilant because situations can change quickly (IK 8866), and publicly clarify halachic positions to prevent misunderstanding (IK 965). A shochet must be deeply G-d-fearing, and even his public conduct affects his reliability (IK 6838, 8713, 2169). Chaplains and communal workers should ensure kosher food, for soldiers and others (IK 3890, 059), and support kosher kitchens and restaurants in communities that need them (IK 1450, 6471).
See also: Shabbos and holidays – Keeping Shabbos; Marriage – Family purity and mikveh.