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General Category => Yeast and Fermentation => Topic started by: heymaa on November 26, 2010, 04:52:37 PM

Title: Yeast Starter Sanitation
Post by: heymaa on November 26, 2010, 04:52:37 PM
So I was making a yeast starter yesterday and due to a boilover in my flask and some messy yeast pouring on my part, I couldn't get the stopper to stay on the flask. Without even thinking about sanitation, I used a paper towel to wipe of the inside of the flask and the stopper...What do you guys think? Buy new yeast? I was thinking about grabbing two vials of white labs for a 5 gallon batch of begian ale and not making a starter since I'll be brewing tomorrow and wont have time to make a new starter.
Title: Re: Yeast Starter Sanitation
Post by: bluesman on November 26, 2010, 05:00:09 PM
Paper towels are sanitary.  You should be okay to proceed with your plans. I wouldn't be concerned with sanitation assuming you used a new papertowel.  I have used papertowels to clean the inside mouth of carboys before without detriment.
Title: Re: Yeast Starter Sanitation
Post by: heymaa on November 26, 2010, 05:03:08 PM
Awesome. Thanks! That just saved me $12, haha. It was a new paper towel, so hopefully all is well still.
Title: Re: Yeast Starter Sanitation
Post by: Kaiser on November 26, 2010, 08:13:55 PM
I agree with the sanitary aspects of paper towels. One thing to have handy in a brewery is rubbing alcohol in a spray bottle. You can use that to spray items you want to have sanitized.

Kai
Title: Re: Yeast Starter Sanitation
Post by: cheba420 on November 27, 2010, 06:40:33 PM
I agree with the sanitary aspects of paper towels. One thing to have handy in a brewery is rubbing alcohol in a spray bottle. You can use that to spray items you want to have sanitized.

Kai

+1 on the spray bottle. I spray the surface and openings of everything from yeast containers, to the funnel to the carboy.
Title: Re: Yeast Starter Sanitation
Post by: James Lorden on November 27, 2010, 07:52:14 PM
A little flame to the lip is also nice.
Title: Re: Yeast Starter Sanitation
Post by: oscarvan on November 27, 2010, 10:07:05 PM
Don't know the results yet, but since I have a bottle of O2 in my shop, I sanitized a few feet of hose and hung it in the wort bubbling away for about 40 seconds during my first batch.

Is there such a thing as over oxygenating the wort?
Title: Re: Yeast Starter Sanitation
Post by: Thirsty_Monk on November 27, 2010, 10:28:19 PM
Don't know the results yet, but since I have a bottle of O2 in my shop, I sanitized a few feet of hose and hung it in the wort bubbling away for about 40 seconds during my first batch.

Is there such a thing as over oxygenating the wort?
Yes there is.
My understanding is that with too much oxygen you get fusel alcohol.
Title: Re: Yeast Starter Sanitation
Post by: tschmidlin on November 28, 2010, 06:46:30 AM
Is there such a thing as over oxygenating the wort?
I haven't tested it myself, but my understanding is that it is not possible to saturate the wort with enough pure O2 that it will be bad for the yeast or beer.  As long as you stop adding O2 when the yeast is added you should be fine, and 40 seconds of pure O2 is not enough to worry about in any case.
Title: Re: Yeast Starter Sanitation
Post by: Kaiser on November 29, 2010, 05:23:03 PM

Is there such a thing as over oxygenating the wort?
Technically there is. In the quest for ever more shelf stable beer the brewing industry is even trying to eliminate wort oxygenation/aeration at the beginning of fermentation. The olive oil experiment was one of these attempts. Other attemps include yeast propagation with lots of oxygen such that the yeast has all the sterol reserves it will need before being pitched into the wort.
 
 
Yes there is.
My understanding is that with too much oxygen you get fusel alcohol.

This is something Jamil has been talking about a lot. The scientific explanation behind this is that excessive oxygen leads to excessive yeast growth. And since fusel alcohols are a byproduct of the amino acid uptake during yeast growth they would also increase.

But w/o a way to disperse the O2 into fine bubbles most of the O2, that bubbles through the wort,  was likely not absorbed by the wort and I’d expect the resulting wort to be under oxygenated.

Kai
Title: Re: Yeast Starter Sanitation
Post by: svejk on November 29, 2010, 05:31:53 PM
...I couldn't get the stopper to stay on the flask.

I agree with the others that you shouldn't have anything to worry about - it helps to remember that we are sanitizing our equipment rather than sterilizing it.  That said, our attention to detail should be especially keen when making starters because anything that happens this early in the process will multiply many times in the main batch.

One thing I'll add is that there was a Basic Brewing podcast a while back where they compared different starter methods and the finding was that it is actually better to cover the starter with foil rather than use an airlock.  Foil will allow more oxygen into the starter and that is beneficial to the yeast.
Title: Re: Yeast Starter Sanitation
Post by: James Lorden on November 29, 2010, 06:44:29 PM
Never built it, but I had an idea for a starter "clean box" not to long ago.  The plan was to take a clear plastic bin.  Cut a whole in it and stick a computer fan or any small fan at one end so that it will suck air out of the box, then cut another whole and put one or more of those sanitary air filters in the other end. when you put your starter in the box you'd turn on the fan which would suck out old air and replace it with the sanitized air.  You could cut a third hole to allow the plug of your stir plate to get out of the bin.

I think this is a cool idea, but I thought it was overkill since I have never had any problems with starter in the past.