diy co2

[cbster]

i built a co2 system 1 week ago. and it looked like it was doing fine. now it won't produce bubbles unless i shake it up. did i do the mixture wrong? or is there something else? i have it at room temp which is 70 degrees. does it need to be warmer? and if yes what do you use? thanks

[Kagh't]

after a while, DIY reactors usually run out of sugar and become uninhabitable for the yeast due to alcohol content. the easist thing to do is empty half the water, but some more sugar in (making sure you leave the yeast in there), and you'll slowly build up a colony of yeast tolerant to higher levels of alcohol. it takes a couple of months, but my system runs for around 3 weeks without needing a top up.

[anonapersona]

I have always used baking soda in my DIY mix because the hagen CO2 system contains it.

I have run an experiment in similar Hagen bottles, using half the regular amount and the other bottle with the regular amount (regular amount is 1 tablespoon baking soda in the Hagen cannister, wich has 2 cups of water).

After one week, the unit with twice the baking soda was making twice the bubbles.

I don't know how acid the waste water is at the end of a generation cycle, it was off the bottom of the charts. My theory is that it is not the alcohol that is inhibiting the yeast, but the acidity.

The baking soad raises the alkalinity of the water, and as the yeast develop and produce alcohol the acidity of the water is buffered.

[Kagh't]

it's both the acidity and alcohol levels that kills yeast.
acidity breaks down the enzymes that conduct the fermentation reaction, while the alcohol kills the yeast itself (thats why fermtation in wines usually stops at aroun 12-17%vol, thats around when the yeast dies).

[DIYMatt]

cbster- Do you use the "Jello" method or just the straight water/sugar yeast method? I had the same thing happen to my first few batches until I switched overto the jello mix method.

While we are on the subject, increasing the size of the bottle(fermenter) helps a lot on both of these fronts. By the shear additional volume of liquid increases the buffering capacity is raised and the percentage alcohol is lowered. Also, using yeast strains designed for alcohol production seems to help. I like the Champagne yeast strain, the one I use is supposed to be tolerant of 18%+ alcohol.

Kagh't- thats interesting about building up a colony resistant to alcohol. How high can you go? I have gotten regular batches well over a month. But when I have tried adding more sugar/water, I have always ended up contaminating the batch somehow and the CO2 production always seemed quite variable in those setups. How stable is your setup and what type of yeast do you use?

[cbster]

what is the jello method i have not heard of that. and does anyone know where to buy champagne yeast? thanks for all the advice

[DIYMatt]

Cbster- I don't know here you can buy champange yeasts on the net, and since freshness and temperature it is stored at is key, I don't if I would suggest it and it would be expensive to ship. I buy mine at a local homebrew/wine making store. Check the yellow pages under homebrew, wine-making supplies, or even hydroponics. Almost all the homebrew stores here seem to double as hydropoincs store. Even if they don't sell wine making supplies, they might have the yeast because indoor gardeners use the DIY yeast CO2 method for their plants.

Now the Jello method. It is basically using gelatin to regulate the yeasts access to the sugar in your CO2 bottle. This evens out the production of CO2 somehwhat to limit the spike you get a few days in and the dropoff near the end of a batch. Also it extends the life of the batch. It seems to work pretty well for me. The exact recipe can be varied to fit your needs. More jello per sugar = longer life, less production, more even. More sugar to jello = faster production, but still even, shorter life. In my 75 I use this new recipe in two bottles and I get 2+ bubbles per second consistantly. 1 packet jello + three cups sugar in a one gallon bottle filled 2/3 full of jello plus the champagne yeats rehydrated per the package instructions. I change one bottle every week. The bottle can last much longer than two weeks, but the longer you use the same bottle the more chance for variable output you have. I used to use 2 packets jello+ 4 cups sugar and kept each bottle for a month, but it just wasn't quite the consistant output I wanted. But, it easily lasted that long. I make my mixes by disolving the jello and sugar in 2/3 gallon of water and letting it cool slightly and then pouring it into the bottle. Then, I let it sit overnight ot set up and then rehydrate the yeast and add it to the mix. I use the entire packet of yeast, But, half the packet should give you the same results. It takes about 6 hours to get going to full output.

BTW if your water isn't hard, mine is very hard. Add a tablespoon or two of baking soda to the yeast when you rehydrate it. It helps harden the yeast shells and buffer the acidity.