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Re: wine yeast



Sylvia wrote:

I finally got fed up with diy co2 via baking yeast. If I'm lucky, a bottle
lasts 2 weeks, with constant (near daily) replenishment of something or
another--extra sugar, new yeast, baking soda. (And I've observed sanitary
measures in mixing it up.)

I reply:

It is quite possible to make a fermentation last about 2 months before the
production becomes so low it is of no use.

Sylvia wrote:

Now here's a baffler. There must have been 10 different types of wine yeast.
I mentioned alcohol tolerance as a plus, and the store owner recommended
*Montrachet* as a good yeast to try. I picked up a few packets, but maybe
somebody's already been through this and has a better recommendation?

I reply:

I don't think the exact type of yeast is all that important. I have only
seriously experimented with two and both work fine. I use S. Bayanus or S.
Cervaisae. You don't want a yeast that foams a lot.

Sylvia wrote:

I was also happy to finally find yeast nutrient. They also had a product
called *yeast energizer*. When I asked about the ingredients of both, he
told
me the yeast energizer was vitamin B12 (which I have in liquid form at home,
so I passed on it), for reluctant yeast colonies. He couldn't help with the
yeast nutrient. I'm curious as to what this is?

I reply:

Yeast nutrient is something that provides Nitrogen to the yeast. If I
remember correctly it is Dibasic Ammonium Phosphate.

Sylva wrote:

I'm wondering if the activity of the yeast will be similar to the baking
yeast, in that it will reach maximum within hours after mixing up, and
maintain or subside a bit (hopefully not as much as the baking yeast!). At
what point does it reach maximum activity? With my luck, this stuff will
start really cooking while not being watched and I'll have a massive mess on
my hands. I used a 5 gram pouch to a 2 litter bottle of water, about 1 cup
of
sugar to start, some yeast nutrient, and a pinch of *tanganyikan salts*
(because it was handy, to help harden the water).

I reply:

I would never start a new batch using yeast nutrient or energiser. If you do
this the production will be very high at first and then rapidly fall off.
This is not just useless but dangerous to your fish. I add baking soda which
helps to mitigate the initial CO2 production but also helps to prolong the
fermentation.

The way that works very well for me is to use 1/2 tsp. of wine yeast, 4 cups
of sugar and 2 1/2 tsp. baking soda in a gallon of water. The way I prolong
the fermentation is I add more yeast nutrient or more when yeast when the
production starts to fall. This is usually after about a week. I think just
adding extra yeast is probably the best as that method maintains a steadier
production. I run two bottles to help maintain a steadier production and
they each average about .6 bubbles per second over the 2 month period. If
you add the nutrition more frequently the production will be higher and but
the fermentation won't last as long. I just like to put in a fresh bottle at
the beginning of the month because it is easier to remember that way so I
have it timed accordingly.

If you don't feel like adding some extra nutition for the yeast then you
shouldn't add nearly so much sugar. The yeast will give up the ghost long
before all the sugar is used up. If you add too little yeast the
fermentation will start lowly and quit early. For a large tank you can use
this recipe and for a small tank you can just reduce the ingredients
proportionately.

It is also very nice to have an accurate bubble counter so you can determine
when to add some nutrition to the yeast. I made one from a plastic pop
bottle with a stopper in the top. I ran the CO2 line into some water in the
bottle and then I ran another line from the top of the bottle to the filter
intake. This causes the whole CO2 system to be under a slight vacuum. This
is OK in my case because I use rigid bottles as CO2 generators.
Unfortunately, this setup also causes the bubble counter to work very poorly
and creates the potential for siphoning tank water into the fermentation
bottles. I never had any luck with this system until I put a Hagen check
valve into the line going into the water in the bubble counter. I actually
put it inside the bubble counter so it is always in the same orientation.
For whatever reason the counter has worked perfectly ever since. If you have
two bottles in that kind of system you will have nothing but grief if you
don't use a check valve. One bottle will siphon into the other or tank water
will siphon into the fermentation bottles during a bottle change or even
after a power failure. It is very suprising what can happen.

I really think I have it figured out to the point where I don't see a lot of
room for improvement in this type of system. For really consistant CO2
levels and very low maintainance you have to invest in a pressurized system.
Temperature, available nutrition, sugar concentrations and alchohol
concentrations can have a big effect on CO2 production. The combined
production of my carefully monitored bottles still varies over the month
from maybe .6 to 1.3 bubbles per second. That is still not that great but it
does grow plants quite well.

I always chart the CO2 production from my bottles and measure the drop in
S.G. from each batch. If you would like to see some of the results I can
Email them to you. It might give an idea of what to expect from a good
fermentation and/or when to add extra nutiton to the yeast.

Wayne