I think practices/standards vary depending on ones locality. In the Western countries there is a more liberal approach to certain foods . Where as in India were Singhs have been practicing bibek for a couple of generations there is a more traditional approach. For example, in India simple raw processed foods such as salt, sugar, pepper, tumeric are acceptable but certain liquid foods such as vinegar are not easily approved.
In the West we have adopted a modern Western diet and bibek has been very complicated. I recently read a book by a journalist name Michael Pollan. He's done extensive research on the processing industry. In his book he mentions how food companies engineer food so their food doesn't perish, but in order to extend the food of life you have to remove the nutrients. I think such food can be detrimental to both the body and spirit.
Living in the West its hard to live up to the standards of Punjab, but i think foods like vinegar are really not a necessity. If you really like it then you can make your own by fermenting sweet apples. Like all vinegar products alcohol is involved in this process and for this reason it is generally avoided by those keeping bibek. If you are looking for a seasoning for your French fries then you can use lemon as js veer Ji suggested or you can use garlic. Both taste good and they are more healthier then vinegar.
ਸਤਿਗੁਰਬਚਨਕਮਾਵਣੇਸਚਾਏਹੁਵੀਚਾਰੁ॥
