Yes, there can be a difference. Some are beautifully deep, smoky and almost thick and some are thin and I may as well use another kind of vinegar because those are not very distinctive. It all reminds me of the differences between cheap and expensive balsamics - and most of the time, there is a good reason the expensive stuff is expensive. I believe some are still being made by old methods and others are being quickly prepared in large factories. But further there are many regional variations on black vinegar as well - from Chinkiang to Mature (from the Shanxi area I think) and then also lighter ones from other areas and even from Japan.
I can't read Chinese either unfortunately but when things are imported they often have an extra label affixed that tells the ingredients in English. Some appear to be pure rice vinegar, some list sorghum, bran, and/or barley among other recognizable grains, others seem to have additives - like sugar, salt, caramel colouring (if I see that last one listed or anything other than the basics, I put it down) ... at least in brands that I have seen side by side in some Asian groceries. Unfortunately the bottles often make it difficult to really 'see' the viscosity or sometimes even the colour so one buys on faith or eenie meenie minny moe. Sometimes though there is only one brand of black vinegar beside other vinegars like brown rice vinegar which look almost identical in the bottle and since I can't read the writing, I have no clue if they are the same thing.
Actually I would love to go to a black vinegar 'tasting'. Perhaps I will have to make this a quest. I love the stuff. But, the ones I like most are the thicker, smoky, rich ones not the watery versions. Side by side they just are not the same animal.
I am, most of the year, a long way from any source for same and never seem to find the same brand twice even when I return to the same store I bought at last time. I have begun saving the bottles of the ones I have liked .. may try to soak off the labels so I can carry them around easily with me when I travel.
