I noticed that every time I did a coffee rinse that I shed like crazy.  The last time there was hair all over my shoulders.  This is not normal for me and I was wondering if the acidity in the coffee could possibly be causing the weaker/damaged hairs to break.  Any ideas?

Did you notice if the hair was a complete hair (has a little bulb/bump on the end)?  Shedding lots of complete hair might occur if you massaged your scalp vigourously and loosened the hair.  If the "shed" hair are partial or broken hairs, then I would think you have other damage occuring that the washing/rinsing is causing the damaged hair to finally let loose.

I agree with bikerbraid; there's probably some other factor that's causing the shedding. I'm no chemist, but my understanding has always been that the acidity is good for one's hair (to a certain point, at least - but coffee shouldn't be nearly acidic enough to cause a problem).

If anything, the extra shedding is probably just due to applying more stress to your hair while applying the rinse. The same thing happened to me the first couple times I used coffee. I'v found that mixing it with a conditioner really helps.

What an excellent idea.  Hadn't thought of that!!