The citric acid-baking soda method with hardware seen in the video has a few advantages over the yeast-sugar based CO2 generator:
1. Ability to shut off the flow of CO2 without excessive pressure buildup. This will conserve the reactants and allow extend batch life.
2. Ability to regulate the flow rate. A valve controls the output. With yeast and sugar, it depends on the amount of yeast, sugar, temperature, pH, alcohol amount, etc.
3. No yeast "creep". In a yeast based system, there is always a chance that yeast will get past the yeast trap and bubble counter, into the tubing and tank.
I have only used the yeast method (before I went pressurized with a CO2 tank) but if I had to do DIY again I would try the method in the video.
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