[dmtaylor]

Sorry, I just couldn't resist.   

If he says he pitches at 167 F and gets good results, and we haven't tried it, truly, who are we to doubt.  I doubt that 100% of the yeast is instantly killed.  Some of them may be mutants, survival of the fittest, and just start working all the faster at the high temps.

[bayareabrewer]

just seems to contradict this

http://www.engineeringtoolbox.com/pasteurization-methods-temperatures-d_1642.html

[Stevie]

just seems to contradict this

http://www.engineeringtoolbox.com/pasteurization-methods-temperatures-d_1642.html

And every middle school biology book from the past hundred years.

[bayareabrewer]

I know of many homebrewers and some breweries that are pasteurizing their wort prior to lacto souring using temps somewhere in the 165 degree range and none report yeast contamination. If you had a successful fermentation, it was probably from something besides the yeast you pitched.

[tommymorris]

...or a broken thermometer.

[dmtaylor]

...If you had a successful fermentation, it was probably from something besides the yeast you pitched.

That is an even more likely theory.

But, no need to respond further.  The troll is gone, and the bait very well consumed.

[Stevie]

Even if it is bait, not disagreeing and leaving it could cause a new brewer to jack up an expensive batch because this wad was trolling.

[charles1968]

Pretty sure he meant 67, as in his second post, and 167 is a typo!

[Andor]

I mostly use 34/70 and it pops up about once a year. It's almost like a mix between oxidation and gym sock in flavor and aroma. The last batch with this problem seemed to improve dramatically after a couple of months in the keg. I also seem to be a lot more sensitive to it than most and sometimes pick it up in certain commercial beers that are lagers. The beer did seem to lag more than most but attenuated well.

I wonder if there is variability in the quality of 34/70. I noticed a weird flavor sort of tart/caramel in my last batch I thought was some sort of mild infection. The identical recipe fermented exactly the same a few months ago didn't have the flavor.

[dmtaylor]

I wonder if there is variability in the quality of 34/70. I noticed a weird flavor sort of tart/caramel in my last batch I thought was some sort of mild infection. The identical recipe fermented exactly the same a few months ago didn't have the flavor.

The very same thing just happened to me.  However, the yeast was like 4 years old so this *could* be my own fault too.