What happend to my yeast?
I bought a jar of Red Star brand "Active Dry Yeast" and used it for 3 batches of DIY CO2, I got about 20 bubbles per minute consistantly for about 10 days with each batch then on the 4th batch I got next to nothing, about 2 bubbles per minute. I've made about 5 mixes using different amounts of yeast, different water temps but nothing seems to work like it did the first few times around. What could have happened, did my yeast go bad?
The recipie I used was about 1/2 teaspoon yeast 2 cups powdered sugar (I've got like 50lb of it from a craft project my wife did, it dissolves faster than granulated sugar and I'll never use all that I have unless I feed it to yeast.) I fill a bottle about 3/4 full of water as hot as the tap will go (~120F) I dissolve the yeast in a drinking cup with about 1 cup of hot water a tablespoon of sugar and 1/2 teaspoon of yeast, after about 5 minutes I dump it into the 2 liter bottle with the sugar water.
Like I said this worked fine for about a month, now it's not working so well at all. I checked the air line for leaks, siliconed anywhere I thought a leak could be coming from and tested in a cup of water right next to the bottle with a short piece of tube to eliminate the longer tube as a possibility, I'm only getting 1-2 bubbles per minute no matter what.
I stored the yeast in the freezer after opening the container as directed on the container. I didn't let the yeast sit out and adjust to room temperature on the first couple batches, just went from freezer to warm water, last time I tried letting the yeast sit out and reach room temperature before dumping it in the warm water, still no luck. I'm tempted to go buy another jar of yeast but I'm not sure if that would make any difference or not, I don't really need two jars of yeast if one will last me a year, the second will expire before I could use it.
I had some blue green algea and some hair algea started growing once the CO2 died so I decided to do a blackout and get everything under controll while I get the CO2 figured out. I've got a few days but once the lights come back on I'm going to need some CO2 again.