pH 4.6
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The acidified definition
Low-acid foods to which acid or acid foods are added, having a water activity greater than 0.85 and a finished equilibrium pH of 4.6 or below.
So acidified is a made category
It starts as a low-acid food and becomes acidified by the addition of acid. The definition describes a process as much as a state.
The low-acid definition
Any foods, other than alcoholic beverages, with a finished equilibrium pH greater than 4.6 and a water activity greater than 0.85.
The exclusion of alcoholic beverages is notable
Which is why the cider and mead property sits in an entirely different scheme, under a 7 percent alcohol threshold rather than a pH one.
And the two definitions share the 0.85 figure
A water activity greater than 0.85 appears in both, so a food below that is outside both definitions. A dried product is not acidified and not low-acid.
Which is why dehydrated storage is a different leaf
One of this group's eight. A dried food is below the water activity gate and its container problem is moisture rather than acid.
The named examples in the definition are worth reading
The acidified definition lists beans, cucumbers, cabbage, artichokes, cauliflower, puddings, peppers, tropical fruits and fish, singly or in any combination.
Which is a list of things nobody thinks of as acid foods
They are not. They are low-acid foods that acid is added to, which is exactly what the word acidified means.
And it includes puddings and fish
Which is a reminder that the category is about the finished pH rather than about the kind of food.
The list is introduced as not exhaustive
These foods include, but are not limited to. So it illustrates rather than bounds the category.
Nothing here tells you how to measure it
A finished equilibrium pH is a measurement with a method, and this property does not describe one.
Or whether any recipe is safe
Which is the question people actually want answered and is not a container catalog's to answer.