couldn't you just use a $9, 2 lb. bags of red star active dry? 21 cakes would be equivalent to 5.25 oz.dry (— 1 cake = 1/4 oz. dry —) so that'd only cost $1.50 a day. you're right, that's a lot.
i read online that brewer's yeast is live — i.e., 'active' — but not the version of brewer's' yeast that's sold as a nutritional supplement. just the real beer yeast — which is also called brewer's yeast.
anyway, i'll look at what my 'lewis labs' brand b y produces tomorrow late afternoon (— 24 hours —) and let you know if it tastes funky or if it has any effect on my system.
i guess what i had in the back of my mind, vis å vis the alcohol question, was 'hard' cider. the store-bought stuff i'm doing this test with is pastuerized so it can't ferment.
maybe the experiment won't work at all and i'll have to try with vitamixed/strained fruit — like you do.