Refrigerate the buns in a shallow container at 4°C (40°F) or below within 2 hours of baking, leaving the lid loose until chilled, then covering tightly. If the room is above 32°C (90°F), refrigerate within 1 hour. Eat within 3 days. For longer storage, freeze for up to 3 months and thaw in the refrigerator. Reheat in a 150°C (300°F) oven, using a food thermometer to check that the centre reaches 74°C (165°F).