Because most condiments have a nearly indefinite shelf life when unopened, the printed dates go entirely out the window once opened and refrigerated. While every condiment has a different threshold, a visual check for changes in consistency and color as well as a sniff test should keep you and your family safe. You should be safe with these foods that won’t ever expire, however.
While the plastic packaging might appear to keep your sandwich fixings fresh, as soon as the slices are separated at the deli counter, their freshness begins to wane. Most sliced meat producers, including Boar’s Head Brand, recommend that their products be consumed within three to five days of purchase, though it should be safe to eat them within 7 to 10 days of the sell-by date. Signs it’s gone bad: If it feels extremely slimy, if it smells remotely of vinegar, ammonia, or yeast, or if there’s any mold or other growth on the meat or the package.