How long is it safe to keep condiment packages from restaurants?
Most condiment packages from restaurants last 1-2 years. Honey, vinegar, salt, and sugar can last indefinitely. Artificial sweeteners you can eat at your own risk.
The ancient Romans used a condiment called garum, which consisted of salt and the entrails of fish, which after being allowed to sit for a long while, became a strongly flavored condiment, used somewhat like relish on various foods. It was not spoiled fish, but the flavor must have been indescribable