Because I just used up the bottle that’s been sitting on the counter all year and noticed its label says “refrigerate after opening.” I opened a new bottle – different brand, but both are pretty much just vinegar and pepper – that just says “shake well.”
I’ve always been taught that sufficient hotness was used to preserve food. Are there oils and stuff in it that could go bad? Unless it’s bloated by some sort of fermentation I would guess the answer is “absolutely nothing”?
Pretty sure I’ve eaten hot sauce from ancient Rome in my pantry