To follow up on the storage of ketchup in particular, many items in cupboards and refrigerators have vinegar listed as a key ingredient. The first things that come to mind are hot sauce, mustard, ketchup. With respect to vinegar as a preservative, is there a rule of thumb in understanding the following:
- how does vinegar work as a preservative; is it solely by virtue of its acidic content?
- aside from the presence of sugars or artificial preservatives, is there a kind of ratio (or other metric) of foods containing, or whose base is, vinegar to know whether something needs to be refrigerated to keep from spoiling?
- what components can act to counteract vinegar's ability to preserve food?
- upon combination, can vinegar stabilize anything that otherwise would spoil? (If yes, you can answer generally, don't worry about a laundry list)
Note: This is asking not about specific jarring/pickling or other long term preservation methods, but rather to the on-use storage of food items in the kitchen and their ability to keep outside of refrigeration without spoiling.
Best Answer
Yes, not a lot of biochemistry is happy living at pH 2 - and the stuff that can live there is already happily living in your gut with a ph of 1
You mean foods already packaged in vinegar? It would depend on how well they had been cooked/sterilized before packaging and how strong the vinegar is. Industrially made pickles will be a lot cleaner than something you pickle at home, but store bought pickles are likely to use much cheaper, more dilute vinegar than your grandmother did.
Anything too alkali will neutralise the vinegar's acidity
Not necessarily, it has to be something where the vinegar can penetrate into the food - it's not going to preserve steaks as well as vegetables. And of course the vinegar taste is going to help if you are trying to preserve say strawberries! Also fungal spores can probably survive dormant in vinegar (if not grow) - fungal spores can survive dormant pretty much anything.