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Re: DIY CO2 problem

james wrote:

I used to use DIY CO2 on a 20 gallon tank. I'd mix everything up, and
within a half hour bubbles would come out like crazy. Then one day it
didn't work anymore. I tried different bottles, different air line,
resealed the bottle, different yeast, different sugar, no luck.
I finally gave up.
Now that I have another 20 going I though I would try it again. Same
luck. Not a single bubble.
The recipe I'm using is 1.5-2 cubs sugar, 2 litres water, 1/4 teaspoon
yeast, pinch of baking soda.
What am I doing wrong?


Sure sounds like a leak but it could be other things. You can check for
leaks by submersing everything in the bathtub and pinching off the CO2
line. The pressure will buid a little bit and you will be able to spot
the leak after a while.

Could be you are not using enough yeast to get your fermentation going.
Using more though is kind of a problem as you will probably end up with
too much CO2 at first then not enough. The recipe you are using means
that about 80% of your sugar will be going to waste. Bread yeast cannot
ferment to high alchohol concentrations and if you add so little yeast
to begin with the fermentation will die from lack of nutrients within a
week. You might have started to wash your bottles between fermentations
instead of leaving a little sludge in the the bottom of your bottle.
This makes a big difference to the nutrients available to the yeast. I
wash my bottles myself because I want the same thing to happen every
time I ferment but this is one of the reasons that people do not get
consistant fermentations. One time the fermentation goes like
gangbusters the next time nothing at all.

Floating yeast will help it's survival rate. They usually explain this
on a packet of yeast. Put the yeast in 1/2 a cup of warm water and let
it rehydrate for 20 minutes before adding it to the sugar water. Not
entirely necessary unless you are just not getting a fermentation going
at all.

Yeast is very temperature sensitive. If your house is too cold you are
going to have problems. Beer yeast is a much better bet than other
yeasts as it will happily chug away at temperatures in the 60s. I keep
all my fermentation bottles with my remote mounted ballasts now. I like
the fact that I get more CO2 production when the lights are on. There is
a lag time to be sure but over night the CO2 builds up anyway and as
soon as the bottles start to cool the CO2 production starts to drop.

There are two good ways to seal an airline tubing to a bottle cap. One
is a rubber stopper with a small hose barb or piece of glass or plastic
tubing shoved into it. The other way is to drill an undersized hole
through the cap, cut the silicone tubing on an angle and yank it through
the hole with a pair of pliers. Don't remove the little gasket from the
cap otherwise the the cap won't seal to the bottle.

I have just set up a 20 gallon tank and so I needed to come up with a
method of producing CO2 in much smaller amounts than I am used to. I
settled on a one gallon plastic gas can (with #8 rubber stopper) and a
sugar limited approach to fermentation. I started with a couple of cups
of sugar water and a 1/2 tsp. of yeast. The sugar water is mixed 8:1
water:sugar. I am thinking of changing it to 10:1 so that it is less
likely alchohol will build up. Every week I add another cup of sugar
water with a pinch of baking soda and a pinch of yeast. It really works
great and provides a small but steady supply of CO2. About one bubble
every 2 seconds. If you exceed the water:sugar ratio you will probably
kill your yeast as soon as enough alchohol is produced. When the
fermentor becomes full you can start pouring off some of the liquid to
make room for more sugar water. If you need more CO2 just add more sugar
water. If you want to use a smaller bottle and/or a 5:1 water sugar
ratio use champagne yeast. Eventually this fermentation will probably
screw up. If the alchohol level gets too high or the pH drops too low
the yeast will die but I should be ale to keep a fermentation going for
several months. I think it has been about 6 weeks so far.

Bread yeast really sucks for producing CO2. It is too fast then too
slow, not alchohol tolerant and too temperature sensitive. If you use it
you can't get good results.