Thanks Dawg. I was hoping to continue this discussion.
I would add:
Why does the bread still bear the characteristics of bread is quite similar to asking “Why does the Word made flesh, still look like flesh?”
St. Thomas used substances and accidents to explain, but that is not so much an explanation as it is a re-description. In the East, they feel no need for it, it just is. And that is sufficient, according to Scripture.
All that said, another way to look at it is in our own experience. If a Protestants thinks of the moment after they were “reborn”. They are a new person - substantially different, different by an order of magnitude. Yet no microscope, blood test, or chemical analysis of their organs or cells will be any different than before they were born again.
If we wish to understand the how of the Holy Eucharist in a similarity to something else we experience or know, we need only look to our own transformation or to the Incarnation.
Good. very good - as is the stuff about the born-again Xtian. I look like the same idiot I looked like before.