So last Thursday (7 days ago) I made a Vienna Lager and pitched Mangrove Jack's Bohemian Pilsner yeast. Expire was coming up in December 2014, stored in refrigerator since it had been received straight from the the wholesaler of the yeast. I rehydrated starting at maybe 5F over the recommended range from Mangrove Jack. Pitched the yeast at 55F after moderating the rehydrated yeast to about that temperature over the course of 20 minutes. I held the fermenter at about this temperature for 5 days. Zero activity. Raised temperature to 70F for 2 days...zero activity. Just pitched an ale yeast since it has been seven days and the airlock still showed negative pressure after warming the fermenter up and swirling out the excess CO2 from solution. So what happened? I am trying to figure out how the yeast could have had a complete die-off. Here's my best solution so far: So I treated the brew water...carbon filtered water, calcium chloride and phosphoric acid...but I never treated the rehydration water. It has chlorine...could the chlorine kill the yeast? Seems like the most logical answer to me...but funny I've never heard of this happening. Does anyone know if yeast could be killed during rehydration by the use of chlorinated water?
The chlorine most likely didn't kill your yeast. Have you checked the gravity of the since pitching? Tasted it? If you swirled out excess CO2 doesn't that imply some activity had started? One dry packet isn't much yeast for a lager. Could be just taking time.
the excess air was just that, excess air in solution that when swirled came out of solution. The airlock had negative pressure on it for two days after giving it a swirl. Zero activity. Gravity still reads 1052, same as brewday.
if you boiled your rehydration water first then cooled it, chlorine shouldn't have been much of an issue. And it would likely take a pretty heavy load of chlorine, even in unboiled water, to kill an entire pack of dry yeast. Haven't used but one or two packs of mangrove jack yeast, but when I did I had no issue with it.
i did boil the water...so both votes are against my logic. Guessing warchez is right...one packet is too few yeasties and it was somewhat of an old packet so just an extremely long lag time. Pitched Burton Union yeast yesterday and holding at 67F, gravity is dropping now. Tastes fine...thanks guys for your feedback
Dave, I am sorry to hear about your woes. We discussed in a past thread the fact that the rehydration temperature for the Bohemian Pilsner was a lower temperature. Did you ever come up for an 'answer' for this temperature difference? Do you think that Mangrove Jack's Bohemian Pilsner dry yeast is hyper-sensitive to rehydration temperature? Maybe this is worthy of an e-mail to Mangrove Jack? Cheers!
Hey Jack, not so much woes, but just not going to be the beer i was hoping for. Tasted pretty good when I sampling it this morning and there was a healthy krausen on top. I did send them an email on that day we last talked, but I never heard back from them. Maybe try a follow up email...but needless to say, I think I'll stick with my go-to liquid lager strains with starters for the time being.
