I don't know what your definition is of "reliable" but my definition of reliable is that they are tested, grown in the U.S. compared to manufacturing plants in China, India, etc. where the FDA rarely regulates those plants, etc. I have read many articles by reliable sources about
these manufacturing plants that scare the heck out of me!
That said, this is why I had used Jernigan Neutraceuticals because the herbs are grown in Kansas and tested using bio-resonance scanning.
They offer tinctures based in apple cider vinegar (I didn't have that option when I was using their tinctures). Below are 2 websites and the 2nd website (iplanethealth) gives the ingredients in each tincture./www.jnutra.com/catalog-apple-cider-vinegar//www.iplanethealth.com/Jernigan-Nutraceuticals-All-Products
Hope this helps!