The alcohol by-product is what inhibits the CO2 production by yeast in
a fixed volume of a DIY bottle.

If you drain out most of the liquid and add new sugar water, the
remaining live yeast will then have a new food supply and the alcohol
will be diluted to a safe level. This allows the yeast to begin the
process over again and generate CO2.

As long as you have a surviving culture, you can reuse the same yeast
for quite some time before it kinda gives up and you have to start
fresh.

On Thu, 06 Feb 2003 05:57:26 GMT, "Dave M. Picklyk"
wrote:

Hmm...slight problem. I've sloshed around all that excess scum on the bottom
with everything else. It's been a couple hours and even though bubbles are
slowly forming in the bottle I've still got not bubbles coming out. I think
it's time for an emergency- quickly get another totally new batch going. I
don't know how long it's going to take the old stuff to start but... who
knows?

So, even if the old stuff gets going good again I should still hook up a
fresh batch?---I heard something here about poisoning the yeast.

Getting confused,
Dave.