Aerator paddle?

Get advice on making beer from raw ingredients (malt, hops, water and yeast)
YeastWhisperer
Sober
Posts: 6
Joined: Fri Aug 28, 2020 10:25 am

Re: Aerator paddle?

Post by YeastWhisperer » Sat Nov 27, 2021 4:27 pm

[quote=PeeBee post_id=860558 time=1637435030 user_id=16274]
That is wrong! However, if you're not confident how well your starter performed, it's best to assume it is "right".

Yeast grown in a good air supply (constantly stirred and stoppered with a very gas porous plug - like the specially created foam stoppers or cotton wool at a push) will store any surplus sterols they create for later, just like yeast being prepared for drying.
[/quote]

Actually, your assertion is incorrect. Most brewing yeast cultures do not need to be stirred because they exhibit the NewFlo phenotype, which means that they will remain in suspension until mannose, glucose, maltose, and sucrose and the higher level saccharides that can be reduced to one of these sugars have been depleted. The presence of these sugars inhibit flocculin, which, in turn, inhibits flocculation. Stir plates are little more than homebrewer snake oil. I wrote a blog entry about this homebrewing myth entitled "Shaken, not Stirred: The Stir Plate Myth Buster" (https://www.experimentalbrew.com/blogs/ ... yth-buster). The person who introduced stir plates to the homebrewing community was a cancer researcher. She was very familiar with growing human cells, which need to be stirred in solution. Brewing yeast cells do not need to be stirred. They need oxygen and a carbon source (sugar is carbon bound to water; hence, the term carbohydrate). Additionally, if one reads my blog posting, one will understand why dry yeast does not need to be aerated. That is due to the fact that dry yeast cultures are propagated aerobically below the Crabtree threshold in a bioreactor, which means that they come out of the process with fully charged ergosterol and unsaturated fatty acid reserves.

Another interesting tidbit is that not all brewing yeast cultures have the same oxygen requirements. Brian Kirsop wrote a seminal paper on oxygen in brewery fermentations: http://onlinelibrary.wiley.com/doi/10.1 ... 614.x/epdf Most brewing cultures sold in the home brewing trade fall into oxygen demand classes O1 and O2, meaning that their oxygen demands can be met by half or full air saturation respectively. I have worked with NCYC 1333, which is a true Yorkshire culture (see photo of fermentation below). NCYC 1333 is an O3/O4 class culture, which can make it cruel mistress in the inexperienced hands. An O3 culture's oxygen demands can be met by pure oxygen saturated wort and O4 culture's oxygen demands cannot be met by even pure oxygen saturate. That is why Yorkshire breweries use fish tail spreaders to aerate ferment mid-ferment.

NCYC 1333 in action: https://i.imgur.com/4CGWRrT.jpg

https://www.ncyc.co.uk/saccharomyces-cerevisiae-1333

One last thing, a starter should never be allowed to ferment out because it places the cells in a quiescent state where their ergosterol and UFA reserves are low (homemade starters use batch propagation above the Crabtree threshold). The entire contents of the starter should be pitched at high krausen. High krausen is the point where the culture has produced the maximum number cells it can produce using the available carbon source and the volume of liquid. Allowing a starter to advance past this point just wastes ergosterol and UFAs; hence, it results in the loss of cell vitality. There is a lot of misinformation in the homebrewing world.
Last edited by YeastWhisperer on Sat Nov 27, 2021 5:23 pm, edited 4 times in total.

User avatar
MashBag
Even further under the Table
Posts: 2140
Joined: Wed Oct 23, 2013 7:13 am

Re: Aerator paddle?

Post by MashBag » Sat Nov 27, 2021 4:45 pm

Ooo good stuff. Sort of holds together with some of what I was taught at enology college.

What does this mean for the addition of olive oil as a nutritional source ?

YeastWhisperer
Sober
Posts: 6
Joined: Fri Aug 28, 2020 10:25 am

Re: Aerator paddle?

Post by YeastWhisperer » Sat Nov 27, 2021 5:20 pm

Olive oil is a source of UFAs, so it is an alternative to aeration. However, the data is scant on its effects on ergosterol. These compounds are necessary to keep yeast cell plasma membranes pliable. A pliable membrane is necessary to take in nutrients and expel waste products. That is why ergosterol and UFAs are part of the vitality equation. When we pitch a starter at high krausen, we are pitching the maximum number of high vitality cells the starter can produce, which, in turn, shortens the lag period after pitching. Too many brewers at the amateur level get wrapped around the axle with yeast counts when yeast cell health is more important. Anywhere from 100 billion to 200 billion cells is more than enough to handle the typical 19 to 23L ale fermentation with ease. They key is healthy cells. I wrote another blog entry entitled "Yeast Culture Are Like Nuclear Weapons" (https://www.experimentalbrew.com/blogs/ ... ar-weapons) that covers how yeast biomass grows in detail. I originally wrote the blog entry back in 2015 and made edits to it 2021. There are several other blog entries in my blog that may be of interest. The top-level URL is: https://www.experimentalbrew.com/blogs/saccharomyces . If one click on the title of the blog entry, the site will display the entire blog entry. I took a several year hiatus from the hobby, which is why there is a gap in the entry dates. I used to post here under the same user name.

For those who are worried about wort dilution by the starter, all that is needed is to boil one's wort additionally down by the size of the starter. That way one should hit one's target O.G. after the starter has been pitched. A properly aerated and propagated starter will be neutral in taste. The foul smell and tastes that one encounters in a stirred starter is due to stress being placed on the culture by the stir bar. A stir bar places shear stress on the yeast cells, which is why starters that are stirred fast enough to create a vortex are low vitality starters. The need for a vortex is the result of using an incorrect piece of labware for making starters. Erlenmeyer flasks were not designed for culturing cells. They were designed for titrating solutions. Their use is just another example of illiteracy replacing knowledge in the homebrewing community. The reason why an Erlenmeyer flask has to be stirred is because its conical shape present a progressively smaller specific surface area as the amount of solution in the flask increases. A vortex increases the specific surface area at the cost of yeast cell health. A large media bottle, small demijohn (we call them jugs in the U.S.), even a 5L plastic bottle is a better vessel for propagating yeast.

Here is my old 5L media bottle after being shaken:

https://i.imgur.com/FQ8YQGx.jpg

guypettigrew
Even further under the Table
Posts: 2626
Joined: Mon Mar 22, 2010 7:10 pm
Location: Christchurch, Dorset

Re: Aerator paddle?

Post by guypettigrew » Sat Nov 27, 2021 6:36 pm

Welcome back, YeastWhisperer--we've missed you!

Guy

User avatar
PeeBee
Under the Table
Posts: 1575
Joined: Thu Jan 21, 2016 2:50 pm
Location: North Wales

Re: Aerator paddle?

Post by PeeBee » Sat Nov 27, 2021 8:08 pm

guypettigrew wrote:
Sat Nov 27, 2021 6:36 pm
Welcome back, YeastWhisperer--we've missed you!
You have? Can't say I've had the pleasure.

YeastWhisperer wrote:
Sat Nov 27, 2021 4:27 pm
Actually, your assertion is incorrect. Most brewing yeast cultures do not need to be stirred because they exhibit the NewFlo phenotype, which means that they will remain in suspension until mannose, glucose, maltose, and sucrose and the higher level saccharides that can be reduced to one of these sugars have been depleted. ...
That's annoying. Others people criticise my stirred arguments because they believe stirring is about keeping the yeast suspended. They don't like it when I suggest its to incorporate oxygen. You take a different view and suggest I'm stirring to keep the yeast suspended and ferment the starters out (did I say that?). That maybe I should be persuading everyone to use orbital shakers like the labs and throw away their newly acquired stirrers? I guess the price difference isn't great?

Before you pile into criticising me, I suggest you straighten up your facts about what I say and mean instead of inventing what you reckon I said so as to inflate your ego?

You appear to be knowledgeable on the matter? Why did you not express the knowledge in a conversational way that we might all benefit (including me perhaps?) instead of using your "knowledge" to try and score points against others.

You can see where that leads.

Your post has been reported for its unnecessarily antagonistic tone.
Cask-conditioned style ale out of a keg/Cornie (the "treatise"): https://drive.google.com/file/d/0BwzEv5 ... rDKRMjcO1g
Water report demystified (the "Defuddler"; removes the nonsense!): https://drive.google.com/drive/folders/ ... sp=sharing

User avatar
themadhippy
Even further under the Table
Posts: 2951
Joined: Tue Dec 08, 2009 12:53 am
Location: playing hooky

Re: Aerator paddle?

Post by themadhippy » Sat Nov 27, 2021 9:33 pm

Your post has been reported for
daring to question my far superior opinionated view.
Warning: The Dutch Coffeeshops products may contain drugs. Drinks containing caffeine should be used with care and moderation

guypettigrew
Even further under the Table
Posts: 2626
Joined: Mon Mar 22, 2010 7:10 pm
Location: Christchurch, Dorset

Re: Aerator paddle?

Post by guypettigrew » Sat Nov 27, 2021 9:39 pm

PeeBee wrote:
Sat Nov 27, 2021 8:08 pm
Your post has been reported for its unnecessarily antagonistic tone.
Hey PeeBee, lighten up!

There was no antagonism in YeastWhisperer's post.

He's always advocated shaking not stirring. In his post he's given his reasons. They may disagree with your reasons for stirring, but isn't that how debate goes?

Guy

User avatar
PeeBee
Under the Table
Posts: 1575
Joined: Thu Jan 21, 2016 2:50 pm
Location: North Wales

Re: Aerator paddle?

Post by PeeBee » Sat Nov 27, 2021 10:07 pm

guypettigrew wrote:
Sat Nov 27, 2021 9:39 pm
PeeBee wrote:
Sat Nov 27, 2021 8:08 pm
Your post has been reported for its unnecessarily antagonistic tone.
Hey PeeBee, lighten up!

There was no antagonism in YeastWhisperer's post.

He's always advocated shaking not stirring. In his post he's given his reasons. They may disagree with your reasons for stirring, but isn't that how debate goes?

Guy
No antagonism? Like "themadhippy's" post, it is nothing personal? And "always"? "YeastWhisperer" joined last year and made 6 posts in that time. Who the hell is this "YeastWhisperer" anyway?

Well, my post has nothing to do with "yeast". It is as is also the case of the posts I'm responding to: Entirely personal attacks! Against forum rules isn't it? I hope someone is reporting my posts so as to deal with them the same way?
Cask-conditioned style ale out of a keg/Cornie (the "treatise"): https://drive.google.com/file/d/0BwzEv5 ... rDKRMjcO1g
Water report demystified (the "Defuddler"; removes the nonsense!): https://drive.google.com/drive/folders/ ... sp=sharing

f00b4r
Site Admin
Posts: 1528
Joined: Fri Jul 11, 2014 10:54 pm
Location: Berlin

Re: Aerator paddle?

Post by f00b4r » Sat Nov 27, 2021 10:26 pm

I’ve just lost my response to this and an not going to type it all out again on my phone now. I will look at the report (I need to see the edits) in the morning.
Peebee you need to stop doing what you accuse others of doing.

Feel free to discuss the merits of the actual topic and beer talked discussions that have flowed from it.

User avatar
PeeBee
Under the Table
Posts: 1575
Joined: Thu Jan 21, 2016 2:50 pm
Location: North Wales

Re: Aerator paddle?

Post by PeeBee » Sun Nov 28, 2021 12:40 pm

f00b4r wrote:
Sat Nov 27, 2021 10:26 pm
I’ve just lost my response to this and an not going to type it all out again on my phone now. I will look at the report (I need to see the edits) in the morning.
Peebee you need to stop doing what you accuse others of doing.

Feel free to discuss the merits of the actual topic and beer talked discussions that have flowed from it.
Grr ... okay, accepted.

I can't alter my response to Jocky the other day (in this thread), if you can change my "exclamation" to a "query", i.e. to "That is wrong?", that should help? I despise bigotry, but probably overstepped the mark there. I didn't keep to my own standards of balancing opinion with humility. Some others might learn from that too?

Anyway, sorry Jocky!
Cask-conditioned style ale out of a keg/Cornie (the "treatise"): https://drive.google.com/file/d/0BwzEv5 ... rDKRMjcO1g
Water report demystified (the "Defuddler"; removes the nonsense!): https://drive.google.com/drive/folders/ ... sp=sharing

User avatar
Jocky
Even further under the Table
Posts: 2738
Joined: Sat Nov 12, 2011 6:50 pm
Location: Epsom, Surrey, UK

Re: Aerator paddle?

Post by Jocky » Mon Nov 29, 2021 10:52 am

PeeBee wrote:
Sun Nov 28, 2021 12:40 pm
Grr ... okay, accepted.

I can't alter my response to Jocky the other day (in this thread), if you can change my "exclamation" to a "query", i.e. to "That is wrong?", that should help? I despise bigotry, but probably overstepped the mark there. I didn't keep to my own standards of balancing opinion with humility. Some others might learn from that too?

Anyway, sorry Jocky!
I actually wasn't offended until you called me a bigot, but changing that sentence to end in a question mark completely fixes that. Well done. =D>
Ingredients: Water, Barley, Hops, Yeast, Seaweed, Blood, Sweat, The swim bladder of a sturgeon, My enemies tears, Scenes of mild peril, An otter's handbag and Riboflavin.

User avatar
PeeBee
Under the Table
Posts: 1575
Joined: Thu Jan 21, 2016 2:50 pm
Location: North Wales

Re: Aerator paddle?

Post by PeeBee » Mon Nov 29, 2021 3:17 pm

Eh? ... Ah! #-o

Jocky: Punctuation failure, or something? I probably overstepped the mark! I was referring to myself being the thing I despised!
Cask-conditioned style ale out of a keg/Cornie (the "treatise"): https://drive.google.com/file/d/0BwzEv5 ... rDKRMjcO1g
Water report demystified (the "Defuddler"; removes the nonsense!): https://drive.google.com/drive/folders/ ... sp=sharing

Post Reply