I had a go at getting those IBD articles but buggered if I could get the site to work after creating an account.
There has been some talk of different yeasts having an effect on the DO, as the yeast itself produces sulfite, and different strains produce more or less of it.
As to my system..
The main part is the 50 litre keg turned into a mash tun set up for vacuum. I cut a hole big enough to be convenient, then used the lid from another keg cut slightly larger, with a plastic fermenter lid O ring in between the two as a seal. I pull a vacuum with a refrigeration vacuum pump, these do a very good job. The atmospheric pressure forces the lid down harder, so even with a little vacuum it forms a great seal and it impossible to remove.
Inside the mash tun is a stainless braid and plate arrangement which works OK. I run a normal HERMS system with a stainless coil to regulate the mash temperature.
Next to it I have an "HLT". This I have set up on a gas burner to boil in order to remove DO. Once the water is boiling I add the normal mash salt/acid additions plus some sodium metabisulfite. Between the HLT and mash tun I have set up a stainless counterflow chiller with a thermowell on the output.
So I load the *dry* grist into the mash tun. I pull a vacuum all the way - this includes all tubing for the HERMS and to the HLT right to the valve. Then I open the valve on the HLT which lets in the boiling water, through the chiller, into the mash tun - the cold water flow on the other side of the chiller regulates the temperature to be appropriate for the mash.
Once the appropriate amount of water has entered the mash tun, I use the refrigeration gas manifold to swap between vacuum and CO2 - thus filling the mash tun with CO2 and relieving the vacuum.
From here I run the HERMS as usual to continue with the mash.
Once the mash is complete I redirect the HERMS output to the kettle. Once a reasonable amount of wort has been drained, I allow water from the HLT to fill from the top to fly sparge. I pull a partial vacuum on the mash tun at this point and the HLT water will actually get sucked in uphill while the HERMS pump fills the kettle.
The boil continues as usual. At some point during the boil I attach a pump and stainless counterflow chiller and recirculate the boiling wort for 10 minutes or so to sanitise the chiller. Then I let the boil go on without recirc.
The fermenter is another 50L keg. I put some water in it, boil the whole thing on a gas burner to sanitise with the coupler attached, then drain the water, then pull a vacuum on it with the output hose of the wort chiller attached - this pulls a vacuum all the way back to the valve so there should be no air between the kettle and the fermenter. I removed the poppet valve from the coupler-ball-valve-adaptor so I can just jam a silicon hose on it.
Once the boil is done I open the valve on the chilling pump - the wort gets sucked through the chiller into the fermenter from the kettle without having to run the pump.
The refrigeration manifold is used again to top up the fermenter with CO2 when the kettle is empty.
Theoretically I have no oxygen in the 50 litre keg so I can put the lot in the fridge overnight to get to pitch temperature with no harm coming to it.