--- In Distillers@yahoogroups.com
, "zap_1961" <scottkstanley@...> wrote:
> A reply to another post today had me asking myself why is it
> to boil the Trub before adding some into the next wash. I assume you
> are trying to kill off any nasties, but at the same time, doesn't
> actually kill off the nutrients as is the usual reason I have
> to add the Trub?
> Maybe it's needed for the non-organic nutrients (mineral/chemical)
> instead of bio material?
> Maybe the reason is for consistency or flavor?
The nutrients we are trying to recover are locked inside the yeast
cells in the trub.
During fermentation, the yeast metabolism process takes up vitamins &
minerals for sustenance, just as all living organisms do. When the
ferment is done, the yeast go dormant as a way of surviving.
So, we have billions of little packages of nutrients (dormant & active
yeast cells). This brings up the question of how to get those spent
little packets to release their payload (nutrients) into a new wash
where there's new yeast that need the nutrients for growth.
Answer: BOIL the trub. This splits the old yeast cells and they spill
their contents, the nutrients. We now have an environment rich in all
the things new yeast needs to grow and multiply, which it has to do
before it can make our alcohol.
Why not just continue with the old yeast (not boiled)? Well in sour-
mashing and back-slopping we do, but yeasts, just like humans, grow old
and no longer perform work well. After several generations they quit
working. Some even mutate into yeasts that make undesirable by-
products. Much the same reason that old humans that produce offspring
have a higher rate of degeneration in their children.
So after several generations of backsetting, we need to introduce fresh
vigorous yeast (which is really 1st generation offspring of a desirable
source yeast, grown for market).
Life is a complicated businness, ain't it?