German Brewing

The bakers yeast is a great proof of concept - could easily just use some starter (for your brew) yeast slurry instead. Would have the added benefit of being probably more active (fresher) and also not containing any of the stabilizers they use for lyophilization of bakers yeast.

Its really cool that there is a relationship between amount of yeast added and amount of DO, I wonder if it goes lower if you add even more yeast?

Its possible that your mash would just turn into a loaf of bread.

There is a lower limit due to the partial pressure driving O2 into the liquid. At a certain point, the yeast can only match ingress. Now, if you did this in a keg, I bet you could get it to nearly zero. Then you could use CO2 (beer gas or inert gas too) to transfer to the mash tun.

Do you sometimes feel like you're in eastern Europe in the 1800s? That's basically where we are, trying to start from the Prussian, Sachsen, Bavarian, Austrian eras of brewing and move forward, recreating the evolution of technologies of the time (decoction, thermometer, grain kilning, refrigeration) and working towards the advanced brewing techniques of today. (while I listen to more Bavarian radio). But I feel like that's what we need to do, start from then and move forward, step by step, to really nail various styles. Each has its own set of criteria and dependencies.

Curious, has anyone tried this in a full batch yet?

I have tried it on a 8 gal batch of water for scale but did not brew with it. It is on my list of things to do though.

I might do it tomorrow

A few years back someone mentioned on hobbybrauer that dead yeast cells are highly undesirable. Whether this is substantiated or not I don't know... However it may be worth a consideration before trying this.