What Volume For O2 In Fermentation.

[Hogan]

The following has previously been recommended as the required O2 ppm for good yeast growth in wort fermentation, however there is never a mention of what volume of wort it relates to.

60seconds of pure O2 (@ 1L/min, .5micron stone) results in about 9.20 ppm O2.

Is this the recommended infusion for 19 liters of wort or is it a general rate no matter what the volume.


Cheers, Hoges.

 

[Wolfy]

Likely that information was quoted from the table on page 79 of the 'Yeast' book:
60 seconds, pure 02 = 9.20ppm, in 20L 18.7P wort @ 24C, 1L O2 per min using 0.5micron stone.

 

[Hogan]

Thanks Wolfy - so I assume that to infuse a 40 liter batch the same volume would be used at a rate of 2 liters per minute. Correct?


Cheers, Hoges.

 

[MHB]

PPM (Part Per Million) doesn't require a volume, it's like saying grams/Litre or Km/h. Just to make it easier 1PPM is the same as 1mg/L or 1/1000g/L. So if you want to add 9.2PPM of O₂ to 22.5 L of wort you are really saying you are adding (9.2 X 22.5)/1000 = 0.207g of O₂ to the wort.

How much you get in there is really going to be a result of so many variables that the true answer is just an educated guess.
Solubility goes up as temperature falls, bubbles get smaller (finer stone) number of bubbles increases (flow rate) (cumulatively the two are surface area) and over pressure increases.

Solubility goes down with rising temperatures, higher wort gravities but the big one will be temperature.

Remember that too much O₂ is toxic and that not enough won't help much; one of the reasons why commercially filtered air is often used, particular in propagators where we are looking for constant growth.

MHB

 

[Ross]

I've done measured tests on a normal 23l volume.

Using a 0.5 micron airstone with pure oxygen, 30 secs resulted in perfect oxygenation.
The flow rate was set so that basically no/little bubbles broke the surface will running.

cheers Ross

 

[Hogan]

Thanks Wolfy - so I assume that to infuse a 40 liter batch the same volume would be used at a rate of 2 liters per minute. Correct?


Cheers, Hoges.

No answer yet defined for the 40-50 liter batch. I would think there are brewers out there somewhere using O2 in this size fermentation. What flow rate are you using.


Cheers, Hoges.

 

[razz]

I'm using O2 Hoges but the reg doesn't have a meter or gauge on it. The next time I use it I will weigh the cylinder before and after. Given Wolfy's info from the yeast book I will use that instead of flow.
Sorry, I meant to say MHB's info.

 

[Hogan]

I've done measured tests on a normal 23l volume.

Using a 0.5 micron airstone with pure oxygen, 30 secs resulted in perfect oxygenation.
The flow rate was set so that basically no/little bubbles broke the surface will running.

cheers Ross

Different strokes for different folks. Ross your rate is half that recommended in the tests carried out by Whitelabs (as per Wolfy's quote from page 79 of the Yeast book).



Thanks Razz. I look forward to your result.


Cheers, Hoges.

 

[Ross]

Different strokes for different folks. Ross your rate is half that recommended in the tests carried out by Whitelabs (as per Wolfy's quote from page 79 of the Yeast book).



Thanks Razz. I look forward to your result.


Cheers, Hoges.

Hoges, guess it comes down to absorbtion rates which is affected by temp & airstone size.
My results were measured with a dissolved oxygen meter & confirmed by another brewer who borrowed the equipment & ran his own trials. So are correct for the equipment used.

cheers Ross

 

[donburke]

No answer yet defined for the 40-50 liter batch. I would think there are brewers out there somewhere using O2 in this size fermentation. What flow rate are you using.


Cheers, Hoges.

was this ever answered ?

recommended is 60 sec for a 5 gallon batch @ 1l/min, so options are;

1l/min for 120 seconds or 2l/min for 60 seconds if the absorption rate is linear

i'm using 02 this weekend for the first time on 40 litres so will try 120 sec @ 1l/min

 

[yankinoz]

An odd note that might be of interest: a Master's thesis described an experiment at a commercial craft brewery, adding a minute amount of olive oil to wort before sending to the fermenter, in place of aeration or oxygenation. I just tried the method, meaning I used the requisite olive oil and eliminated deliberate aeration (pouring wort from a height, etc.). Fermentation went well using Wyeast 256. The thesis stated several possible benefits, notably improved stability, but for a home brewer the advantage might be not bothering with fishtank aerators or oxygen tanks. But like a lot of home brewers I've never used them and never had trouble starting a fermentation.

Why would olive oil replace oxygen? Read the thesis at www.brewcrazy.com/hull-olive-oil-thesis.pdf.

 

[donburke]

An odd note that might be of interest: a Master's thesis described an experiment at a commercial craft brewery, adding a minute amount of olive oil to wort before sending to the fermenter, in place of aeration or oxygenation. I just tried the method, meaning I used the requisite olive oil and eliminated deliberate aeration (pouring wort from a height, etc.). Fermentation went well using Wyeast 256. The thesis stated several possible benefits, notably improved stability, but for a home brewer the advantage might be not bothering with fishtank aerators or oxygen tanks. But like a lot of home brewers I've never used them and never had trouble starting a fermentation.

Why would olive oil replace oxygen? Read the thesis at www.brewcrazy.com/hull-olive-oil-thesis.pdf.

i have tried the olive oil in the past, after reading that article, and honestly didnt notice any difference

i havent used o2 before either, yet my beers tend to turn out just fine, but this weekend i'm making a bigger beer than i normally do and want to give it the best chance to attenuate properly

 

[razz]

I'm using O2 Hoges but the reg doesn't have a meter or gauge on it. The next time I use it I will weigh the cylinder before and after. Given Wolfy's info from the yeast book I will use that instead of flow.
Sorry, I meant to say MHB's info.

I completely forgot about this thread but I do recall adding 10g oxygen to my last 40lt brew. Now according to MHB's info above I've added 250ppm. Seems like a lot for such a small amount of oxygen. The beer was fine so I guess a lot must have got lost in the process. I could use 1g and get 25ppm which would be adequate.

 

[donburke]

for the record, i made a 1.062 beer on saturday, 20 litres of it got 60 seconds @ 1l/min through a 0.5 micron stone and 40 litres of it got 120 seconds

i havent seen a fermentation this vigorous since brewing my first beer @ 28 degrees

its now day 3 and all is mostly done ... cant wait to taste the finished product