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stirring a yeast starter

http://www.thebrewingnetwork.com/forum/viewtopic.php?f=19&t=33334

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Re: stirring a yeast starter

Posted: Sat Jan 28, 2017 10:57 pm
by NateBrews
Interesting, I didn't ever put the stir bar in the boiling wort because I wasn't sure if it could take the heat. If it can, in it is going to go from now on.

On the cold water bath subject, I don't know about others but I always keep the level of the bath so that the cold water is at a lower level than the wort. I think I heard that you can have high temperature differentials across the borosilicate glass if you have material on the other side of it. So, if I put it in a deep water bath maybe it would crack in the section that is empty (top). That sounded reasonable to me since you can put it on the stove and it doesn't break, and the burner is pretty hot but is only exposed to the area with liquid on the other side of the glass.

Thanks for the input!

Re: stirring a yeast starter

Posted: Sun Jan 29, 2017 7:12 pm
by Charlie
I think stir bars are coated in teflon. I run them through the pressure canner every time I make a starter, and it has no effect on them.

You're probably safe as long as you immerse the flask below the liquid line, but I once had an incident in the lab where I was heating a Pyrex erlenmeyer with a couple liters of 2 molar sodium hydroxide on a hot plate, and it shattered. Talk about a mess! The Fisher Scientific rep told me that Pyrex gets more fragile when it goes through a bunch of heat/cool cycles. He may have been trying to deflect the blame for a defective product, but I don't have better data.

Charlie

Re: stirring a yeast starter

Posted: Wed Feb 01, 2017 12:32 pm
by SoCal Surfer
Thanks everybody. next starter is up and running. I'm not going to smell it and freak myself out.

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