Question About oxygenating Your Wort

[Chris_Dog]

This one?
http://www.listermann.com/Store/Details.asp?ID=434

 

[SuperiorBrew]

Sorry it was Williams that I got mine from, you can buy it as a kit or just the wand.

WILLIAM'S OXYGEN AERATION SYSTEM

 

[Chris_Dog]

Thank you sir!

 

[cudaman]

does the aeration time change based on the volume of wort? I brew 20 gal batches, and was wondering if I need to increase my time.

 

[SuperiorBrew]

does the aeration time change based on the volume of wort? I brew 20 gal batches, and was wondering if I need to increase my time.

I do it 2x as long for my 10G batches than I do for my 5's

 

[Scotty_g]

We use the cheapest oxygenating rig possible--we have a bernzomatic torch bottle and regulator hooked up to a length of aquarium air hose and an aquarium air stone. The hose was $2 for 25' and the stones are two for a buck. We throw the hose and stone into some one-step when we start the boil so it's good and clean when we're ready to bubble it up. After we top off the primary we bubble oxygen in for about a minute, then throw out the stone and wash the hose.

Typically we see the airlock starting to bubble in about 8 hours and haven't detected any off flavors. As far as I can tell, we must be using about enough O2.

As far as how much oxygen you can get in, water will hold about 8 ppm at pitching temperature and one atmosphere--that's it--if there's air above the water. Any excess oxygen will bubble out (although it may take a little while). Similar to how you can purge the headspace of a keg or carboy with CO2 to prevent oxidation, you could purge the container with oxygen to get > 8 ppm in the wort. The industrial wastewater plant I deal with at work does this, but trust me--what the microorganisms are consuming there is a *lot* nastier than malt.

 

[Baunno]

Dumb question as I have never done anything other that give the wort a good stirring before pitching the yeast but....would using a small aquarium pump and a fish tank stone work to airate the wort before the pitch?

 

[wildwest450]

Dumb question as I have never done anything other that give the wort a good stirring before pitching the yeast but....would using a small aquarium pump and a fish tank stone work to airate the wort before the pitch?

That's what I use, except I use a stainless air stone (easier to sanitize). I usually let it run for 20-30 min for a 5.5 gallon batch

 

[Baunno]

That's what I use, except I use a stainless air stone (easier to sanitize). I usually let it run for 20-30 min for a 5.5 gallon batch

Thanks for your response! I'll brewing a clone of Three Floyds pale ale this Sunday and it'll be my first batch both propagating and aerating the yeast. I'm looking forward to an improved brew!

 

[mykayel]

If you are using the stainless airstones made for oxygenating (not the aquiarium stones) remeber not to touch the stone as the oils in your hands can clog them.

Personally I would only use O2 (and you only need about 60 seconds) and not inject air for a half hour.

While this article was written about yeast culturing, much of the information still applies and it discusses teh effects of yeast growth in starters on the actual brewing stage.

http://www.maltosefalcons.com/tech/MB_Raines_Guide_to_Yeast_Culturing.php

In terms of fermentation, aeration is also important but only in the early stages (first 6-24 hours). Aeration in later stages can oxidize beer constituents and lead to the development of off-flavors. Since aeration sets the stage for maltose fermentation and alcohol tolerance, it is easy to envision why insufficient aeration could lead to stuck fermentations or incomplete fermentations. Incomplete fermentations can be manifested as either high finishing gravities or the production of off-flavors especially diacetyl, acetaldehyde, and hydrogen sulfide. Insufficient aeration is also associated with excessive ester formation. The profound effect of aeration on yeast is further illustrated in studies where yeast from a poorly aerated beer was repitched into aerated wort and still did not perform well. Thus insufficient aeration can have a long-lasting effect on yeast.



In general, it is difficult for homebrewers to achieve sufficient oxygen levels. The levels of oxygen necessary for optimal fermentation vary depending on the yeast strain. Ale strains usually need between 8-12 part per million (ppm) while lager strains require slightly higher amounts (10-15 ppm). At atmospheric pressure the maximum level of dissolved oxygen in wort is approximately 8 ppm and the saturation level decreases further as the gravity of the wort increases. Thus unless special steps are taken to introduce air or oxygen into the wort, it is difficult for homebrewers to achieve adequate aeration. Recent studies have shown that oxygenation is by far more efficient than aeration. Injection of oxygen through a 2 micron diffusing stone can actually supersaturate the wort with 10-12 ppm of dissolved oxygen being reached in 5 gallons of wort by a single 60 second blast of oxygen!

 

[Darth Lefty]

The O2 and stone method is probably better but here's what I do:

Dedicate a bit of hose to this: Siphon cooled wort from brew pot to fermenter. Put a small hole in the hose so that the siphon system leaks in a little air. If you are doing extract brewing you can run the rest of the water through this too, just pour it into the brew pot as the level runs low.

 

[bnick3]

Time to bring this thread back to life I guess.
Did some google research on wort oxygenaton last week and came across this guy
http://www.beertools.com/html/articles.php?view=245

who says to not oxygenate your wort but oxygenate the yeast instead. Ok that makes sense I guess if you oxygenated your starter enough to facilitate reproduction to the point the yeast only needs to convert the wort to alcohol. But then why do pro brewers oxygenate their wort? Is this guy on to something or on something?

 

[dirt55]

Funny that you bring this up. JZ was just talking about this on "brew strong" within the last couple months, probably on their oxygenaion show. He stated that it totally makes sense AND works...but that it lacks any characterisics of yeast flavor in the final product and is "too clean" causing a final product that is inferior to the brews that allow some yeast reproducing in the wort. Great show to listen to.

 

[NBBC13]

tried it today with the benzomatic tank and stainless air stone. The regulator I got from Northern Brewer didn't fit/screw into the O2 tank, so I had to hold it down. it bubbled like crazy and I only did it for 60 seconds. Based on my experience at work, where I do a lot of De-oxygenations by bubbling Argon or Nitrogen through solutions and suspensions, I can't imagine that anything over 60 seconds is necessary if you're blowing at high velocity.

 

[NewBrewerTFM]

Every molecule of Oxygen that you can contain in the primary fermenter with the cork and air lock will make your yeast as happy as bunnies in the spring time. The yeast require the oxygen to reproduce and convert your wort into tasty yeast byproducts. Your wort will likely be saturated within a few minutes. Regardless weather you are pumping oxygen into your wort or relying on atmospheric oxygen, you should still agitate the piss out of it to optimize the oxygen saturation in the wort. AFTER THIS POINT YOU WOULD LIKE TO NEVER EXPOST YOUR PRODUCT TO OXYGEN UNTILL POURED INTO YOUR GLASS. Good luck with that part.