Putting pure O2 through a stainless diffusor stone does the same thing without having to sanitize a pump. However, many a crafty brewer will put that stone inline with their tubing leading to the fermenter to maximize the contact.
I don't know if you've heard one of the more recent episodes where the original author of the experiment called in and explained that his DO meter was defective and giving reading of up to 2.5 ppm in a sample that should have been close to zero. He mentioned he'd repeat the experiment with a new meter and more aeration techniques. I only hope he uses real wort this time.
okay, so shaking works great.
problem is my back is not what it used to be.
Not having heard the podcast yet, but I am concerned with how they calibrated the dO probe. The ones I use in my fermentors at work have to have the span set. First, make sure there is no O2 in the sample (sparge with nitrogen, or use freshly autoclaved media) and set this as 0%. Then, fully oxygenate using air (which is usually what we use for aerating during growth) and set that as 100%.
So, the 100% is going to be the max you aerated during set up. If I calibrate using air, then blow O2 in, I'd get up to something like 200% dO tension.
The difference between water and wort wouldn't be as important as making sure the correct 100% point is calibrated. Dissolved oxygen tension is a relative scale not an absolute scale like ppm or molarity.
Plus, if the probe was off, then the experiment is useless. Period.
It's already been said a couple of times, but I'll just reiterate. A method that works really well, and doesn't require any back-breaking shaking is this:
Wrap one, or ideally two, sanitized hop bags to the end of your auto-siphon and siphon through these hop bags into your carboy. It turns the beer into a fine spray as it goes into the carboy and aerates the crap out of it - Three plus inches of foam on top of the wort every time. This is all I've done for 2 years after 1 year of the shaking method. With this siphoning method, I've never had a slow start, I've never had contamination, and my back feels great.
I certainly don't want to degrade the guy who took the initiative because I also fancy myself a half assed garage scientist.
the amount of foam sitting on top of the wort in the fermenter is not a good indicator of dissolved oxygen. I have a great head on top of my keg poured beers and there's no oxygen in the beer at all.
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