Generally, it's best to consume leftovers within 3-4 days when refrigerated properly. Whether leftovers are safe for tiffins two days later depends on how they were stored and the type of food.
The safety of using leftovers for tiffins two days later hinges on several factors. First, consider how quickly the food was cooled after cooking. Bacteria thrive in the 'danger zone' between 40°F and 140°F (4°C and 60°C). Leftovers should be cooled to below 40°F within two hours. This can be achieved by dividing large portions into smaller containers.
Second, proper refrigeration is crucial. Ensure your refrigerator is set to 40°F (4°C) or below. Store leftovers in airtight containers to prevent contamination and maintain freshness.
Third, consider the type of food. Some foods are more prone to bacterial growth than others. Cooked rice, for example, can harbor Bacillus cereus, which produces toxins even after reheating. Similarly, foods containing dairy, eggs, or seafood require extra caution. If the leftovers contain any of these ingredients, it's best to err on the side of caution and consume them sooner rather than later.
Finally, when packing the tiffin, ensure it's kept cool. Use insulated lunch bags and ice packs to maintain a safe temperature until lunchtime. If there's any doubt about the safety of the leftovers, it's always best to discard them.
To extend the shelf life of leftovers, consider freezing them immediately after cooling. Frozen leftovers can be safely stored for much longer and thawed when needed for tiffins. Just ensure they are thoroughly reheated before consumption.