Most consumers have at some point played the 'sniff test' game with food that is slightly past its date, but this practice can be dangerously misleading for certain items. While a 'best-before' date indicates peak quality, a 'use-by' date on highly perishable goods is a hard deadline for safety. Beyond this point, invisible and harmful bacteria can multiply to dangerous levels, even if the food appears and smells fine.
The Crucial Difference: 'Use-By' vs. 'Best-Before'
Understanding the subtle but critical difference between these labels is your first line of defense against food poisoning. The label manufacturers apply is determined by the potential risk of the food.
What 'Use-By' Means
A 'use-by' date is a safety warning. It is the last day a manufacturer recommends a product be consumed to ensure it is safe. This applies to highly perishable items that can host dangerous pathogens like Listeria, Salmonella, or E. coli. You should never consume food after this date, regardless of its appearance or smell, as these pathogens can't be detected by your senses.
What 'Best-Before' Means
A 'best-before' date indicates peak quality, not safety. Food may begin to lose its optimal flavor, texture, or nutritional value after this date, but it is not necessarily unsafe. Many shelf-stable and non-perishable foods carry this label, and you can often rely on your senses to judge their quality after the date has passed.
High-Risk Foods to Avoid After the Expiration Date
Certain foods are magnets for bacteria and should be discarded immediately once they pass their 'use-by' or expiration date, even if they look and smell normal.
Deli Meats and Cured Products
Deli meats are a common source of Listeria, a bacterium that can grow even in refrigerated conditions. Consuming contaminated cold cuts can lead to listeriosis, a serious illness, particularly risky for pregnant women, older adults, and those with weakened immune systems. The USDA recommends discarding opened deli meat after five days, regardless of the date on the package.
Soft Cheeses and Unpasteurized Dairy
Soft cheeses like brie, feta, and ricotta are moist environments where harmful bacteria such as Listeria can flourish. Unlike hard cheeses, where mold can sometimes be trimmed, the mold in soft cheeses can penetrate the entire product. Similarly, unpasteurized or 'raw' milk poses a serious risk of contamination with dangerous pathogens and should be discarded past its use-by date.
Fresh and Ground Meat
Raw ground beef, chicken, and other fresh meats should never be consumed past their expiration date. Grinding meat increases the surface area exposed to bacteria, making spoilage happen faster. Pathogenic bacteria like E. coli and Salmonella are common contaminants in raw meat and can cause severe foodborne illness. A sour smell, slimy texture, or grayish color are definite signs to throw it out.
Raw Fish and Seafood
Seafood is highly perishable and can harbor bacteria that cause botulism, a serious and potentially fatal form of food poisoning. Signs of spoilage include a strong, fishy or ammonia-like odor, a slimy texture, and cloudy eyes. Once fresh seafood is past its prime, it should be discarded immediately.
Restaurant Leftovers
While not labeled with an expiration date, restaurant leftovers should be treated with extreme caution. They often contain multiple ingredients with varying shelf lives and have been exposed to room temperature during transportation. Dietitians recommend consuming leftovers within three to four days to be safe.
High-Risk vs. Lower-Risk Expired Foods
| Feature | High-Risk Expired Foods | Lower-Risk Expired Foods |
|---|---|---|
| Examples | Raw meat, seafood, deli meats, soft cheeses, unpasteurized dairy, infant formula. | Canned goods, dried pasta, rice, flour, crackers, spices, honey. |
| Expiration Label | Typically 'Use-By' for safety. | Often 'Best-Before' for quality. |
| Primary Danger | Growth of pathogenic bacteria (e.g., Listeria, Salmonella, E. coli). | Loss of quality (e.g., staleness, diminished flavor), rarely unsafe unless packaging is compromised. |
| Sensory Test | Unreliable. Pathogens are often undetectable by smell or sight. | Can be reliable. Check for mold, off odors, or stale taste. |
| Course of Action | Throw it out. Do not consume under any circumstances. | Assess quality. If no signs of spoilage, often safe to consume. |
Infant Formula: The Critical Exception
Infant formula is the only food product where federal law mandates a 'use-by' date for safety. Past this date, the nutrient levels in the formula may decline, which is a serious issue for an infant’s development. Always discard infant formula after its expiration date to ensure it meets the labeled nutrient specifications.
The Bottom Line: When in Doubt, Throw It Out
While reducing food waste is an important goal, your health should always be the top priority. For highly perishable items, particularly those with a 'use-by' date, the risk of foodborne illness is simply not worth it. For pantry staples and products with a 'best-before' date, use your best judgment based on sight, smell, and taste. For more information on safe food handling, you can consult the official guidance from the USDA.
Conclusion
Navigating expiration dates requires an understanding of what the labels mean and which foods carry the most significant risks. Focusing on a 'zero-tolerance' approach for high-risk, perishable items like deli meats, soft cheeses, raw seafood, and infant formula is the safest strategy. By being an informed consumer, you can make smarter choices, protect your family from foodborne illness, and reduce waste on lower-risk items without compromising safety.
