Cover leftover soup, eggs and potatoes and refrigerate promptly at 4°C (40°F) or below. Eat within 2 days, or sooner if an ingredient’s use-by date or instructions after opening require it. Avoid freezing: kefir can separate and cucumber loses its crunch. Discard perishable food left out for more than 2 hours, or more than 1 hour above 32°C (90°F).