Aeration (including Olive Oil vs. Aeration)

[bwarbiany]

This is one of those things I need to add... Now that we have temp control for fermentation, rapid cooling, etc, O2 is pretty much top of the list.

Jon, to give you an idea of the importance -- I've brewed some really good beers. But one type of beer has ALWAYS given me major problems; anything high-gravity. For a while I thought it was the temp control, or underpitching yeast, and both of those are out of the equation. But the high-grav beers have still been elusive. The last thing I can place it on is improper aeration.

[^Respect]

chiming in on experiments i found very interesting.

http://www.youtube.com/watch?v=vOrfmzpDmPk [ Dry Yeast Experiment ]
http://www.youtube.com/watch?v=A734B5E1C3U [ Aeration/Oxygenation Experiment ]

this guy bobby has some really nice videos on his channel that cover allot of areas in DIY home-brewing.

btw sorry I couldn't make it this weekend for all the festivities, gotta throw the money into working on the hooptie. Cheers~

[JonGoku]

chiming in on experiments i found very interesting.

http://www.youtube.com/watch?v=vOrfmzpDmPk [ Dry Yeast Experiment ]
http://www.youtube.com/watch?v=A734B5E1C3U [ Aeration/Oxygenation Experiment ]

this guy bobby has some really nice videos on his channel that cover allot of areas in DIY home-brewing.

btw sorry I couldn't make it this weekend for all the festivities, gotta throw the money into working on the hooptie. Cheers~

Thanks for posting. Thats some interesting insight and kinda contradicts some of the "common sense" knowledge out there. I'm curious though about the relationship of short lag time vs longer lag time when compared to taste/flavor differences is not explained. I wonder...

[bwarbiany]

Thanks for posting. Thats some interesting insight and kinda contradicts some of the "common sense" knowledge out there. I'm curious though about the relationship of short lag time vs longer lag time when compared to taste/flavor differences is not explained. I wonder...

In all honesty, while homebrewing offers a load of chances for trying new techniques and new ideas, brewing has been going on for 10,000 years. While I'm not going to claim that the science is entirely settled, I think you're going to do far better listening to the advice of the guys who do it professionally (Tyler & Patrick, or buying a serious brewing science book) than you will from a few youtube videos.

[brahn]

I haven't watched the Youtube videos yet, but Tyler will tell you that you don't need to oxygenate if you're using dry yeast. The yeast is dried with everything it needs to do it's thing. With liquid yeast, it's a very different story and while monitoring lag time is popular with homebrewers it really doesn't tell you much of anything.

[bwarbiany]

I haven't watched the Youtube videos yet, but Tyler will tell you that you don't need to oxygenate if you're using dry yeast. The yeast is dried with everything it needs to do it's thing. With liquid yeast, it's a very different story and while monitoring lag time is popular with homebrewers it really doesn't tell you much of anything.

Is this also true for very high-gravity beers (noting that I try to pitch at the rate of 2 packs of dry yeast per 5 gallons of brew on the high-grav stuff)?

[brahn]

Yes, I believe so. At least I'm pretty sure that's what Tyler's told me. You do need to pitch more yeast like you're doing.

I know that I've brewed several high gravity (1.100+) beers with dry yeast and no oxygenation that have turned out very good. I typically aim for pretty high attenuation levels too, especially in big beers, and I've never had any problems hitting 80%+ AA.

[tylking]

Oxygen is always a good thing to have/add in your wort or yeast. First generation ADY comes with oxygen already in the cell; make sure to re-hydrate the yeast properly though. High gravity beers are probably going to need an extra source of oxygen; ADY doesn't carry enough to support itself in such a harsh environment. If you plan on re-pitching the ADY after not oxygenating the first generation I wouldn't! I haven't watched the videos but by watching your lag time you can get an idea of the vitality of the yeast, assuming you are pitching the same amount of yeast each time and have some understanding of how long it usually takes. I measure the DO levels in the wort after knockout to watch our yeast vitality.

[brahn]

Thanks for clarifying Tyler.

[JonGoku]

Valid comments and true words of wisdom from Tylor, but I still think one should watch the videos before commenting on a conversation spawned by them.

The experiments are conducted in a fairly formal scientific method and interesting enough.

Cheers!

[tylking]

He leaves out two VERY important details: cell growth and DO levels. Cell growth directly affects the flavor of the beer and stability of the yeast in serial re-pitching. He should send the yeast samples to the lab and see how the stress changed its DNA and/or plate them and see if any petite mutants are present now.

[JonGoku]

Tyler, thanks again for your comments and further input. You take us to a whole new level with your expertise.
I found an article from White Labs I think that addresses the points you made.
Diacetyl Time Line
Fermentation Time Line

To save people from actually having to click the link , here are a few excerpts I believe that make the point.

Diacetyl gives a buttery, butterscotch-like flavor to beer. The flavor threshold of diacetyl is 0.1 parts per
million (ppm) in "light" beer. Homebrewed beer can have levels from .05 to greater then 1.0 ppm. Factors
that influence the diacetyl level in beer are fermentation temperature, aeration level, bacterial
contamination, and the yeast strain used.

Fermentation parameters that effect diacetyl levels are temperature and aeration. High
fermentation temperatures promote diacetyl production, and low aeration levels when yeast is pitched will
produce less healthy yeast, which are prone to higher diacetyl production.

[Brewbud]

Yeast uses the O2 to produce Sterols for healthy yeast growth and cell walls. There are ways to do this without any O2 at all. You can find a paper on an easy way to do it here:

http://www.brewcrazy.com/hull-olive-oil-thesis.pdf

In the end it comes down to are you happy with your brews. Are you happy with your attenuation? Are you happy with the ester production of your yeast? Is there room for improvement? Yeast is such an important aspect of brewing (IMHO the most important). Anything thing you do to affect the yeast will most likely affect your beer. Experiment a little. Borrow an O2 system if you can. You may find you love the results. You may find you are unhappy with the change (possible reduced Ester production).

For the past two years I have been experimenting with the olive oil technique. I have been surprised and happy with the results. The amount of oil I use in a 10 gallon batch is a single tiny drop from the tip of a bamboo shish ka bob skewer.

BTW - I used to inject O2 right into my line right after my CFC.

[backyard brewer]

Yeast uses the O2 to produce Sterols for healthy yeast growth and cell walls. There are ways to do this without any O2 at all. You can find a paper on an easy way to do it here:

http://www.brewcrazy.com/hull-olive-oil-thesis.pdf

In the end it comes down to are you happy with your brews. Are you happy with your attenuation? Are you happy with the ester production of your yeast? Is there room for improvement? Yeast is such an important aspect of brewing (IMHO the most important). Anything thing you do to affect the yeast will most likely affect your beer. Experiment a little. Borrow an O2 system if you can. You may find you love the results. You may find you are unhappy with the change (possible reduced Ester production).

For the past two years I have been experimenting with the olive oil technique. I have been surprised and happy with the results. The amount of oil I use in a 10 gallon batch is a single tiny drop from the tip of a bamboo shish ka bob skewer.

BTW - I used to inject O2 right into my line right after my CFC.

That's interesting. I'd read all about this when it first came out a few years back but I've never come across anyone who's actually been doing it.

[JonGoku]

Any issues with head retention?

So you add a tiny drop from oversized tooth pick for a 10gal batch. How to you cut that in half for a 5 gallon batch?