preservation vinegar question

[pwb]

When a sauce need vinegar, what is standard vinegar, is it 7% ?

 

[The Hot Pepper]

Vinegar is acetic acid and water (7% acetic acid diluted with 93% water) so it doesn't really matter, you can always balance your sauce with more water or add more vinegar etc. depending on how you like it. Once you figure out what works best for you go for that. 

Some people work with 100% acetic acid and dilute it themselves.

What you can do is figure out the type of vinegar you like best. That is more important. 

 

[SmokenFire]

When a sauce need vinegar, what is standard vinegar, is it 7% ?

 
Most food service applications use vinegar at 5% acidity, which is what most grocery stores sell.  Handily most recipes (like Ball canning pickle and such recipes) call for using at least 5% vinegar so I'd call that 'standard'.  That 5% is what you'll find in white distilled vinegar, and usually apple cider vinegar is 5% too (in my experience at least).  
I am able to get 10% vinegar from a local farm supply store, which is helpful for certain things.  
 
What THP said above is certainly true; you can always balance by adding more and it's most important to find a vinegar you like that will work for you.  Several respected sauce makers here use rice wine vinegar, I like apple cider for some stuff and distilled white vinegar for other uses.  
 
Be wary of using other vinegars with unknown (or lower than 5%) acidity though, as that can produced undesired results.