Refrigerate leftovers in separate shallow, covered containers within 2 hours, or within 1 hour if the surroundings exceed 32°C (90°F). Keep at 4°C (40°F) or below and eat within 3–4 days. If the kefir’s use-by date or recommended time after opening is sooner, follow that limit. Freeze the pork and gravy for longer storage. Reheat the pork to 74°C (165°F) throughout and bring the gravy to a boil. Keep the cucumber-kefir sauce refrigerated and serve cold.