As a chemist who hates the English system of measurement when I stumbled
upon this group I thought I had found the holy grail!

Question 1) All of my books give measurements is cups. I can convert water
cups to grams, but the density of flours varies all over the map. I have
made my own approximations for the wt. of a cup of rye, bread flour, and
all-purpose flour. Is there a consensus for this conversion?

Question 2) A local supermarket produces quite acceptable sour dough bread.
I smiled real big and got a loaf of unbaked sour dough bread for the price
of a finished loaf. I brought it home, chopped it up into 8 pieces, put
them in baggies and threw them into the freezer. I have subsequently
unthawed one of them, restarted it with 1/2 cup of water and 1/2 cup of
flour. Subsequent interactions on this theme have given me a very fast
rising starter, but the bread has no sour taste. Reading all of the
literature it seems that I am not letting the dough rise long enough. (2 hrs
first rise and something less than that for the second). The dough almost
triples in bulk during this time at room temp. Should I cool the dough or
has freezing it killed the bacteria component of the starter?