dstar26t
If it's worth doing, it's worth overdoing
I'm... skeptical... of something reading 300ppm. Maybe dstar meant ppb?
That's calculated ppm at 100% efficiency, only 5.8% of it was dissolved so there was 17.5 ppm in solution measured.
I'm... skeptical... of something reading 300ppm. Maybe dstar meant ppb?
Demus said:I'd like to see these too. I did read in "Yeast" that air only has 8 ppm or so, making it impossible to get more than 8 with any non-O2 method. Being involved in both aviation and scuba diving, I understand a bit about how gasses diffuse into liquids. Basically the bigger the differential (called partial pressure) the faster the rate of diffusion. So if you target is 8-12 ppm, you can only get to the minimum of your target and it will take a LONG time to get there because of the low partial pressure. This fits with test I read done by White Labs that found 5 minutes of "vigorous" shaking only resulted in 2.7 ppm dissolved oxygen. I believe this is one of the biggest causes of problem fermentations among newer brewers.
Another test that you might consider would be to skip using the wand and instead flood the head space of the fermentor with O2 for a few seconds then shake the fermentor for 30-seconds. Do this flood and shake process a total of two times then measure the results. I read elsewhere recently that this is another good way to oxygenate wort with pure O2 without the wand. I'm curious what level of dissolved O2 this method would achieve.
Thanks for posting your results!
I would be interested in seeing what the spray aerator can do. My LHBS says that is what he uses and sells with his kits. I have used it for both my brews. However I really want to get more oxygen in I think it has to do with my weak fermentation.
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* using a medical oxygen regulator with the lpm setting won't work as a flowmeter here, unfortunately. that's only accurate for unrestricted flow[...]
I have been searching for where it says that you only get 2.7 ppm from vigorous shaking. I did try wyeast website. I am very curious about this. Do you still have a link for this info? Thanks!
Also I heard from white labs that you can get 8 ppm from vigorous shaking (but I doubt it) unless you can pick up the whole bucket and shake the crap out of it.
Thanks
* using a medical oxygen regulator with the lpm setting won't work as a flowmeter here, unfortunately. that's only accurate for unrestricted flow, and we have restricted flow due to the airstone, and to a lesser extent, the atmospheric pressure of 15 in or so of liquid above the outflow. so it has to either be a thorpe tube style volumetric flowmeter inline from the tank, or just regulator psi. reg psi will be a decent number since, if another guy is using the same micron airstone, his rig should act more or less the same as yours, and same psi/time should give same ppm DO. the advantage of the thorpe tube is that it will also tell you how much of your tank you're using per bucket, which is also a concern.
Great info here, I started adding pure O2 to my wort before I even started doing yeast starters and saw great improvements in my fermentation.
I haven't figured out what they use in the small medical 'flow meters'. I'm guessing either a needle valve with preset detents (like used with a Thorpe tube, but set at the factory), or a fixed orifice with a variable backpressure. Either way, or even if it's a different way, I doubt the ~2psi downstream backpressure affects the rate much, since the upstream pressure is likely 60psi or greater. I can't see them getting accurate/precise single digit psi changes with a diaphragm that small. That said, the Thorpe tubes are a much more accurate meter when dealing with variable downstream pressures. If someone combines a Thorpe tube flow meter with one of the cheap medial flow meters with/without a stone attached, we would know for sure how much downstream backpressure affects them.these regulators do not actually have a volumetric flowmeter in them, they have simply been calibrated to select a certain psi which, during their normal usage of unrestricted flow of gas out the feed tube, will result in the selected lpm shown on the selector knob.
On the other hand, if shooting in a little oxygen means that I don't need to make a starter then it is a big time saver.
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