[RC]

I oxygenate whenever I use liquid pitches. Never done a side-by-side, but way back when, as I was learning and trying new things, the two biggest jumps in quality for my beers happened when I started making starters and oxygenating the wort. Oxygenation can also help compensate for sub-optimal yeast health, and so it's also an insurance policy that is worth the effort to me. I'm firmly in the pro-oxygenation camp for liquid pitches.

It should be done right at pitch time. O2 is not very soluble in liquid. If the O2 concentration in the wort is above the atmospheric concentration (~8ppm IIRC), the O2 is going to want to gas off to reach equilibrium. If you wait a long time to pitch after oxygenating, you're probably not realizing the full benefit of the >8ppm O2.

I put my O2 wand in the kettle I use to heat up the sparge water. Effectively sterile once it hits 160F. No need to boil or chemically sanitize it. In fact, you're wasting time with chemical sanitizing because there's no way liquid is going to get into those pores.

[majorvices]

Major - are you saying that the wort must be chilled to pitch temperature to adequately absorb oxygen into the liquid through inline injection, for however transitory that may be?  If so, could lagers be racked at ale temps and oxygenated inline to the fermenter, then allowed to cool down to fermentation temps without concern about oxygen remaining sufficient?  Just wondering about the dynamics here - does the oxygen stay in the wort as it cools to its ultimate fermentation temp or is it "driven out" by the cooling process or absorbed by the yeast scavenging or both?

I have been using a wine de-gassing stirrer for batches that are re-pitches and liquid pitches - it gets pretty frothy and the yeast seem to make fast work of absorption/uptake.  My last lager was re-pitched into 64F wort (as cool as I could get it by immersion chilling in 90F+ ambient temps last Saturday).  It was racing within 4 hours and fermented at 58F for five days and completed well attenuated (1.040 to 1.005)...I can't imagine that it "needed" O2 by inline injection, but I have a stone that I haven't used in a few years, because the wine whip seems adequate (all my beers are pretty low OG, though).  I may just revisit O2 injection.

I try to pitch soon after aeration for the reasons RC mentions. But I don't know how long it takes for wort to "degas" of o2. I imagine it takes longer than a few hours, but I do think it is important to get them close. As far as the degassers go, I have never used that but obviously it works because so many people use it.

I have never used in line aeration on homebrew unless you count the venturi pump I used years ago. But I have used them commercially. I brewed tonight on a pretty sweet Premier Stainless 20 bbl. But it doesn't have a cold liquor tank and the ground water here in the south is pretty damn warm. For a reasonable heat exchange vs pump speed I couldn't get the wort below 95 -- at the end I was ready to go and speeded up the pump and hit temps of 107. No need inline aerating at those temps IMO. Best to just aerate the tank in the morning after cooled to temps before pitching.

[Bilsch]

I put my O2 wand in the kettle I use to heat up the sparge water. Effectively sterile once it hits 160F. No need to boil or chemically sanitize it. In fact, you're wasting time with chemical sanitizing because there's no way liquid is going to get into those pores.

Actually liquid goes right through those pores.. even the 0.5 micron ones.

[RC]

I put my O2 wand in the kettle I use to heat up the sparge water. Effectively sterile once it hits 160F. No need to boil or chemically sanitize it. In fact, you're wasting time with chemical sanitizing because there's no way liquid is going to get into those pores.

Actually liquid goes right through those pores.. even the 0.5 micron ones.

Actually, no. You’ll get some minor entry of water at the hydrostatic pressures typical of homebrewing, but very little. It’s easy to test for yourself. You’ll need some extra pressure to get a liquid cleanser or sanitizer to permeate all those pores.

[Bilsch]

Actually, no. You’ll get some minor entry of water at the hydrostatic pressures typical of homebrewing, but very little. It’s easy to test for yourself. You’ll need some extra pressure to get a liquid cleanser or sanitizer to permeate all those pores.

The water wicks right into the pores. Just because it does not flow though without pressure does not mean they are not filled. If you are trusting this as a method to keep the stone contamination free.. you are foolish.

[RC]

Actually, no. You’ll get some minor entry of water at the hydrostatic pressures typical of homebrewing, but very little. It’s easy to test for yourself. You’ll need some extra pressure to get a liquid cleanser or sanitizer to permeate all those pores.

The water wicks right into the pores. Just because it does not flow though without pressure does not mean they are not filled. If you are trusting this as a method to keep the stone contamination free.. you are foolish.

Just the opposite. I don't trust it. That's why I pasteurize. Like I said, it's easy to test for yourself.

[Saccharomyces]

I put my O2 wand in the kettle I use to heat up the sparge water. Effectively sterile once it hits 160F.

When I use the word "sterile" with respect to yeast, I am referring to absolutely sterile, which means complete absence of life, including spores. For the truly anal brewers among us without access to a pressure cooker that can reach 15 psi above sea level atmospheric pressure (a lot of European-made pressure cookers can only reach 13 psi, so processing time are increased), boiling the stone three days in a row (Tyndallization) renders it absolutely sterile.  The flash Pasteurization temperature of 160F is for vegetative cells only, but should be good enough for brewing because wort is not absolutely sterile.

[Saccharomyces]

I have linked Brian Kirsop's seminal publication on oxygen demand in brewery fermentation below.  It is where the oxygen demand classes O1 through O4 were originally defined. One encounters this nomenclature on a regular basis in the large culture collections.  The most popular yeast cultures in amateur brewing are low-oxygen demand strains.  The higher O2 demand cultures have been weeded from the home brew market.  The word "forgiving" is almost a surefire sign that a culture is class O1 (4ppm dissolved oxygen).

Oxygen in Brewery Fermentation

https://onlinelibrary.wiley.com/doi/pdf/10.1002/j.2050-0416.1974.tb03614.x

For example, here is the description of NCYC 1333, which is a class O3/O4 Yorkshire culture that I used to have in my old bank:

Information             Flocculent. O3/O4. Head forming Yorkshire Stone Square type recommended for bottled Pale ale.
Depositor                British Brewery
Deposit                   Name Saccharomyces cerevisiae
Month of deposit      January
Deposit Year            1974
Ale production strain Yorkshire Stone Square type recommended for bottled Pale ale.

Here is the glass vial in which the culture was shipped on slope (slant to us).



Here is what the culture looks like in use:



The culture flocs to the top and looks like pancake batter.  It has to be "beaten back" into the fermentation either via vigorous mixing or through the use of a fish tail spreader. The only culture that comes close to this one in the home or craft brewing markets is multi-strain Ringwood and that culture has traditionally only been available to Alan Pugsley-built breweries.  NCYC 1333 produces beautiful bitters, but it can also be a cruel mistress to use because of its oxygen demand.

[Bilsch]

Just the opposite. I don't trust it. That's why I pasteurize. Like I said, it's easy to test for yourself.

I have and that is why I store the stone in a 4% NaOh soln between uses. Always get some crud that soaks out.

[kpfoleyjr]

 


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Anyone else use one of these with an O2 bottle and a wand?


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[majorvices]

 


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Anyone else use one of these with an O2 bottle and a wand?


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Yes, but only have ever used flowmeter commercially. Would be a good addition for homebrew if you could figure a way to rig it to the red o2 bottles.

[kpfoleyjr]

Here’s a pic of my setup - works well.


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[majorvices]

That's pretty sweet! And who doesn't like zip ties? 

I may have to give this some serious consideration. I don't like how temperamental my gauge is.

[fredthecat]

My last lager was re-pitched into 64F wort (as cool as I could get it by immersion chilling in 90F+ ambient temps last Saturday).  It was racing within 4 hours and fermented at 58F for five days and completed well attenuated (1.040 to 1.005)...I can't imagine that it "needed" O2 by inline injection, but I have a stone that I haven't used in a few years, because the wine whip seems adequate (all my beers are pretty low OG, though).  I may just revisit O2 injection.

this is one of a few reasons im purposely lowering my OGs slightly and greatly reducing the number of high gravity brews im making this coming year. at an OG of 1.045 or less i think the O2 is not really an issue at a level i would care about. but where i struggled a lot was higher OG attempts.

i also did take some advice from this forum on the idea of starters and will be improving that.

im aiming to just use the venturi effect spray. but i am trying saccharomyces' concept of -healthy, vitalized yeast but not a massive starter and ideal growing conditions. not simply a massive starter. i want to increase the yeast character in the beer

[Saccharomyces]

this is one of a few reasons im purposely lowering my OGs slightly and greatly reducing the number of high gravity brews im making this coming year. at an OG of 1.045 or less i think the O2 is not really an issue at a level i would care about. but where i struggled a lot was higher OG attempts.

It is not that O₂ is less of an issue with lower gravity wort.  It is that the O₂ saturation level is higher in lower gravity wort.  This phenomenon can be seen on table 1 of the Kirsop publication that I linked in a previous post.  The reason why we pitch more yeast into high gravity wort is because it is more difficult to dissolve O₂ in high gravity wort coupled with the high osmotic pressure that wants to draw the water out from inside of the yeast cells, resulting in a loss of turgor pressure, which can cause premature cell death.  In effect, we need more yeast cells because it is more difficult to grow the yeast biomass coupled with the threat of early cell death.

i also did take some advice from this forum on the idea of starters and will be improving that.

im aiming to just use the venturi effect spray. but i am trying saccharomyces' concept of -healthy, vitalized yeast but not a massive starter and ideal growing conditions. not simply a massive starter. i want to increase the yeast character in the beer

A venturi is not a spraying device.  A venturi is a device that causes a rapid drop in pressure resulting the creation of vacuum that sucks in air and mixes it with the liquid.

The venturi shown below is made from piece of 1/4" ID, 3/8" OD racking cane.  While it appears to do so at first glance, wort does not spray out of the holes due to Bernoulli's principle.  The ID is the typical racking plastic hose is 5/16" or 3/8".   The ID of the venturi is 1/4".  This reduction in diameter causes an increase in fluid flow while simultaneously causing a reduction in pressure.  The result is that air is sucked in through the holes and mixed with the wort while passing through the acrylic tubing when it is held vertical.  We are taking advantage of physics to aerate our wort.  One needs to be careful with the fluid flow rate because the foam head on the wort can grow to five or more inches.