Re: YES YES YES !!! I think I have a piece of the puzzle too:

Great information! Thanks...I had not come across any of this before stumbling into the actual e-book.

Yes, for me anyway, the reaction is extreme...Apple Cider Vinegar will cause my face to flush pink, which is very apparent on me, since I'm fair-skinned and I can feel my heart beating fast...don't even have to check my pulse.

I'm super-sensitive to everything that goes on with my body, so the pulse method is very easy for me. For someone less in touch or conscious of themselves, this method can be incredibly useful to determine the difference in pulse rates with foods you'd just never suspect!

I believe I have an extreme gluten intolerance, and I read someplace that when Apple Cider Vinegar is fermented, cross-contamination with gluten can happen and that's why some people have my reaction. Can't remember where I read this though.