One of the oft asked questions is whether our Drippin' Sauce Ketchup needs to be refrigerated or not.
The technical answer is no, refrigeration is not required. However, the recommendation is that you DO refrigerate ketchup after opening the bottle.
Ketchup, more specifically tomato ketchup, is made with vinegar and tomatoes among other ingredients. The acidic (pH) nature and the lengthy cooking at or near the boiling point should prevent the growth of any bad stuff. The pH when bottled is at 4 +/- a small tolerance. That's acidic.
Our ketchup (as with all commercially available ketchups -- or catsup if you want) has been tested by an independent lab for "shelf life". Shelf life is literally "long".
Clearly, the unopened bottle does not require refrigeration...it can be left in the pantry until you are ready to use it.
The major difficulty ketchup encounters is oxidation...air causes that dark red semi-dry stuff you see around the cap. Any ketchup can oxidize (even that stuff you see on tables in burger joints.) So keep the lid on the bottle either in or out of the fridge.
The reason we recommend refrigeration after the bottle is opened is to retain the complexity and richness of our ketchup with a flair for flavor...keep the flair!