Speaking only of my own comfort level, I would not be concerned using the lower acidity vinegar for a 100% vinegar recipe but since it's on the lower end of the acceptable range, with, say, a 50:50 ratio of vinegar to water, I would use the stronger vinegar.

I would guess that 5% figure is a simplification and a way to avoid the problem of people who are inclined to push boundaries. That way if someone does use rice wine vinegar there is that additional latitude, even if they're not aware of the fact.

Carol

So as Carol said, if it is a straight vinegar brine I'd be comfortable with it but I wouldn't use it in a diluted brine recipe.

You know you can contact Dr. Elizabeth Andress at NCHFP directly by email if you want to clarify the guideline even more.

Dave

"● Multiply the volume of 5-percent vinegar in the original recipe by 1.16 (because 5.0 divided by 4.3 equals 1.1627906). The result is the volume of 4.3-percent vinegar in your revised recipe.

● Subtract the volume of 5-percent vinegar in the original recipe from the volume of 4.3-percent vinegar in your revised recipe. Reduce the volume of water in the revised recipe by this amount."

The answer is: you mix 55% vinegar to 45% water (roughly).
The final mixture should have about 2.5% acetic acid.

.............................
(4.5)/(100 +x) = 0.025
x= 80
added water to vinegar ratio = (80)/(100+80) = 0.444

Note: this is not mathematically exact. but close enough