Directly oxygenating yeast-not wort, have I missed something?
Started by
Thirsty
, Sep 29 2009 03:56 PM
6 replies to this topic
#1
Posted 29 September 2009 - 03:56 PM
I am reading George Fix's Principles of brewing Science- great read BTW. And he makes mention of hot side vs cold side aeration in the oxidizing chapter. a direct statement is: "it is useful to make a distinction between hot-side aeration and cold-side aeration. The hot side includes events from mashing through wort chilling. When the wort is cool, oxygen is added to the wort or, more common these days, to the yeasts, before the yeasts are pitched."Now when he states more common these days to the yeasts, how exactly is this done? That he does not mention, and I am assuming he is talking about on a brewery lab scale of things, however this is a process I have yet to run across, and am curious as to its role and occurance level. Am I being blockheaded about something here?
#2
Posted 29 September 2009 - 04:45 PM
Sounds like a starter to me.
#3
Posted 29 September 2009 - 05:30 PM
Dunno, sounds like oxygenating slurry. Small breweries harvest and repitch. The big boys and the larger craft breweries probably handle it differently with harvested yeast. It sounds like a messy proposition for the homebrewer though. It would seem easier and as effective to just oxygenate after pitching but what do I know. Still using the SS stirrer & cordless drill here after pitching.
#4
Posted 29 September 2009 - 05:36 PM
Didn't you read my whole post? I guess it may be exactly what he is referring to. What trips me up is the verbage of "or" implying that oxygenating yeast does not require oxygenating wort. So i think now, if using my stirplate to make a starter, is my process of adding pure O2 to the wort over-saturating with O2? I know awhile ago it was either dj or Stangbat (I think?) that went out and bought an O2 meter to measure saturation, and time how much and how long to add O2 to wort before pitching. And excessive overoxygenating is just as bad as underO2ing, where does a starter contribute? And if the starter's saturation is just enough for healthy starter growth, and wort saturation is still a must- then why the "or" ? I am probably reading way too much into this, without actually being able to measure, it is all just guesswork anyhow.Am I being blockheaded about something here?
#5
Posted 30 September 2009 - 09:51 PM
Here's my 2 cents.
#6
Posted 01 October 2009 - 08:45 AM
I have a copy of that book. It has many confusing statements such as your example. This is why it sits on my shelf and is goes unread.Do not get me wrong, I understand how important the book is and the contribution it has made to homebrewers. I am happy that others read and understand it. I get the benefits of the book by proxy.zymot
#7
Posted 01 October 2009 - 01:36 PM
It is definitely the most analytical and comprehensive book of brewing I have ever read, once I realized there would be so many formulas and molecular models, I stopped breaking each one down and figured they were all right, so as long as I grabbed the concept of the process they describe, I could get where he was going with each one, and then I could use them for reference in the future if ever need be. I am taking the BJCP exam in another 6 weeks, so I wanted to have a couple formulas and models to "dazzle" a little in my essays to try to woe the judges a bit. I figure if the opportunity arises to include something other than basic principles it may score me slightly higher- need every point I can get!I have a copy of that book. It has many confusing statements such as your example. This is why it sits on my shelf and is goes unread.
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