[Oiscout]

I just recently purchased an oxygen tank and aeration stone for my next set of brews. After some research it seems that simply pouring your wort into the carboy and shaking it repeatedly was not sufficient enough aeration. (Still not sure on all the facts). So I ran a little test on my yeast starters one aerated and one was not. The one that was aerated absolutely BLEW UP. The one that was not. Not so much I got some yeasties working in there. But I also wonder if it also depends on yeast strain. Matching. Gravity and volume and temperature. That was the best controls for experiment I could come up with.

Anyone have any thoughts or insight on aeration? (If that is the correct term)

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[Saccharomyces]

You are not imagining things.  As I have started many times, a yeast culture does not need to be spun. It needs to be pitched into well-aerated wort. The amount of dissolved O₂ at time of pitching matters.  Also, as I have stated many times, there is no magic in an SNS starter.  The SNS method of making a starter is little more than a poor man's O₂ bottle.  Pitching an SNS starter at high krausen is integral to its performance.

[Oiscout]

The way it's looking it'll be high high krausen at time of pitching tomorrow, I no chill and it gives me plenty of growth time for my starters

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[Saccharomyces]

Your starter will be at high krausen way before tomorrow.  High krausen is usually reached in 12 to 18 hours, often sooner.  I would suggest placing the starter in a refrigerator when you see low krausen forming to retard the fermentation.   You can pull it out of the refrigerator when you start your brew day.

[Oiscout]

That's s great idea thanks for the advice

I didn't expect it to take off like it did!

[Oiscout]

Took your advice, pitched this 6 hours ago  WLP300 is a work horse!

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[fredthecat]

yup absolutely. however, i think different yeast strains do have greatly different oxygen requirements. i've never had attenuation issues before ever, even on big beers or meads. i am struggling right now with WLP500's attenuation, and the only variable i'm missing is pure oxygen.

i went out to buy a can of bernzomatic the other day but they were sold out at canadian tire.

what kind of release valve (?) did you use oiscout?

[fredthecat]

You are not imagining things.  As I have started many times, a yeast culture does not need to be spun. It needs to be pitched into well-aerated wort. The amount of dissolved O₂ at time of pitching matters.  Also, as I have stated many times, there is no magic in an SNS starter.  The SNS method of making a starter is little more than a poor man's O₂ bottle.  Pitching an SNS starter at high krausen is integral to its performance.

i was listening to an interview with chris white and he was saying the exact same thing, that oxygenation is equal in importance to pitch rate.

[Oiscout]

This is my rig

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[Oiscout]

yup absolutely. however, i think different yeast strains do have greatly different oxygen requirements. i've never had attenuation issues before ever, even on big beers or meads. i am struggling right now with WLP500's attenuation, and the only variable i'm missing is pure oxygen.

i went out to buy a can of bernzomatic the other day but they were sold out at canadian tire.

what kind of release valve (?) did you use oiscout?

I got a dark mild going with WLP005 I tried 002 and I liked it but I'm experimenting, and that beer is in a bucket so I hadn't gotten a look at it yet it was trucking earlier this week I'm doing Diacetyl rest on it now

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[Saccharomyces]

i was listening to an interview with chris white and he was saying the exact same thing, that oxygenation is equal in importance to pitch rate.

One can underpitch as long as there is enough dissolved O₂.

[Saccharomyces]

yup absolutely. however, i think different yeast strains do have greatly different oxygen requirements. i've never had attenuation issues before ever, even on big beers or meads. i am struggling right now with WLP500's attenuation, and the only variable i'm missing is pure oxygen.

Yes, different yeast strains have different O₂ requirements, but most of the strains available to amateur brewers are O1 or O2 with respect O₂ demands.  How are you aerating?  Are you using a venturi? Splash aeration will get one to O1 (half air saturation) at best.  A venturi will get one to O2 (full air saturation).

Here is what I use to aerate wort:




It is a piece of racking with holes drilled downward in the flow of the wort.  It functions as a venturi even though it does not look like a traditional venturi.  The device is placed vertically at the end of the tubing draining one's kettle into one's fermentation vessel.  The inside diameter is 1/4".  When used with 5/16" or 3/8" tubing, the wort pressure flowing through it drops while the flow rate accelerates.  This phenomenon is known as the Bernoulli principle.  The result is a vacuum that draws and mixes air through the holes.  If used correctly, it will create a head of foam large enough on top of the wort that one will have to slow down the flow in order to allow the foam to dissipate.  When dealing with yeast, foam is good.

By the way, if you want to learn more about O₂ demands, here is a link to Brian Kirsop's seminal paper on the subject: https://onlinelibrary.wiley.com/doi/epdf/10.1002/j.2050-0416.1974.tb03614.x

[pete b]

yup absolutely. however, i think different yeast strains do have greatly different oxygen requirements. i've never had attenuation issues before ever, even on big beers or meads. i am struggling right now with WLP500's attenuation, and the only variable i'm missing is pure oxygen.

Yes, different yeast strains have different O₂ requirements, but most of the strains available to amateur brewers are O1 or O2 with respect O₂ demands.  How are you aerating?  Are you using a venturi? Splash aeration will get one to O1 (half air saturation) at best.  A venturi will get one to O2 (full air saturation).

Here is what I use to aerate wort:




It is a piece of racking with holes drilled downward in the flow of the wort.  It functions as a venturi even though it does not look like a traditional venturi.  The device is placed vertically at the end of the tubing draining one's kettle into one's fermentation vessel.  The inside diameter is 1/4".  When used with 5/16" or 3/8" tubing, the wort pressure flowing through it drops while the flow rate accelerates.  This phenomenon is known as the Bernoulli principle.  The result is a vacuum that draws and mixes air through the holes.  If used correctly, it will create a head of foam large enough on top of the wort that one will have to slow down the flow in order to allow the foam to dissipate.  When dealing with yeast, foam is good.

By the way, if you want to learn more about O₂ demands, here is a link to Brian Kirsop's seminal paper on the subject: https://onlinelibrary.wiley.com/doi/epdf/10.1002/j.2050-0416.1974.tb03614.x

The good old Bernoulli effect from grade school science. I remember the example as when taking a shower the moving water resulted in lower pressure which would cause the air outside the shower to move towards the low pressure, pushing the shower curtain in. Hence the need for weights on the bottom of shower curtains.

[HopDen]

I just recently purchased an oxygen tank and aeration stone for my next set of brews. After some research it seems that simply pouring your wort into the carboy and shaking it repeatedly was not sufficient enough aeration. (Still not sure on all the facts). So I ran a little test on my yeast starters one aerated and one was not. The one that was aerated absolutely BLEW UP. The one that was not. Not so much I got some yeasties working in there. But I also wonder if it also depends on yeast strain. Matching. Gravity and volume and temperature. That was the best controls for experiment I could come up with.

Anyone have any thoughts or insight on aeration? (If that is the correct term)

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If I am repitching yeast, I aerate first then pitch. If I am using dried yeast, I first sprinkle yeast onto wort, wait 15-20 mins then aerate.

[Richard]

It is a good idea to put a HEPA filter inline between your oxygen tank and your bubbler. Something like this:
https://www.morebeer.com/products/sanitary-filter.html