Tippsy-Turvy
Well-Known Member
I’m not making any assertions here as I don't have a dissolved oxygen meter to do the experiment so the following charts and ideas are based purely on speculation. But, this is a genuine question so any intelligent responses are greatly appreciated.
Now I’ve only recently learned how crucial pure oxygen is to properly oxygenate wort for lagers and high OG ales. However, I’m finding pure oxygen setups really quite expensive but simple air aeration techniques only oxygenate the wort to 8ppm, max.
Soooooo, can one achieve a higher average level of dissolved oxygen (DO) by aerating the wort to 8ppm multiple times (whether by shaking or pumping air through a diffusion stone) compared to a single application of pure oxygen done to, say, 12ppm at the beginning? Of course, all aeration should only be done during the lag phase and before fermentation begins.
My thinking follows. During the lag/reproduction phase, when most of the oxygen is absorbed, I’m guessing the amount of (DO) in the wort will drop by exponential decay as it gets consumed. Since the lag phase begins within an hour of pitching and lasts 12-24 hours, surely this could be a window when we can safely reapply aeration techniques to bring the DO level back up to 8ppm again thereby keeping the average oxygen level elevated during the entire lag phase?
We can estimate and compare the average levels of oxygen in the wort throughout the lag phase if we make broad assumptions (the rate of oxygen consumption by the yeast is the same irrespective of the starting level of DO, the DO level falls by exponential decay, we assume any diffusion of new oxygen into the wort from the headspace is very slow and the lag phase is largely complete after 12hours). Then, if the pure oxygen, single injection method produces a starting DO level of 12ppm, the average DO during the first 12 hours would be ~2.3ppm. However, aerating the wort to 8ppm at the start and repeating 6 hours later, the average DO level would be ~3.0ppm. If the second aeration is done 3 hours after the first the DO level would be ~2.7ppm – still higher than the single shot of pure O2.
Actually, come to think about it, wouldn’t continuous aeration by an air pump for, say, 6 hours be beneficial particularly given there’s no risk of over-oxygenating the wort when using air?
Sorry that I have no answers – only questions.
Now I’ve only recently learned how crucial pure oxygen is to properly oxygenate wort for lagers and high OG ales. However, I’m finding pure oxygen setups really quite expensive but simple air aeration techniques only oxygenate the wort to 8ppm, max.
Soooooo, can one achieve a higher average level of dissolved oxygen (DO) by aerating the wort to 8ppm multiple times (whether by shaking or pumping air through a diffusion stone) compared to a single application of pure oxygen done to, say, 12ppm at the beginning? Of course, all aeration should only be done during the lag phase and before fermentation begins.
My thinking follows. During the lag/reproduction phase, when most of the oxygen is absorbed, I’m guessing the amount of (DO) in the wort will drop by exponential decay as it gets consumed. Since the lag phase begins within an hour of pitching and lasts 12-24 hours, surely this could be a window when we can safely reapply aeration techniques to bring the DO level back up to 8ppm again thereby keeping the average oxygen level elevated during the entire lag phase?
We can estimate and compare the average levels of oxygen in the wort throughout the lag phase if we make broad assumptions (the rate of oxygen consumption by the yeast is the same irrespective of the starting level of DO, the DO level falls by exponential decay, we assume any diffusion of new oxygen into the wort from the headspace is very slow and the lag phase is largely complete after 12hours). Then, if the pure oxygen, single injection method produces a starting DO level of 12ppm, the average DO during the first 12 hours would be ~2.3ppm. However, aerating the wort to 8ppm at the start and repeating 6 hours later, the average DO level would be ~3.0ppm. If the second aeration is done 3 hours after the first the DO level would be ~2.7ppm – still higher than the single shot of pure O2.
Actually, come to think about it, wouldn’t continuous aeration by an air pump for, say, 6 hours be beneficial particularly given there’s no risk of over-oxygenating the wort when using air?
Sorry that I have no answers – only questions.