Grain Crush Astringency Myth?

This forum has proven time and time again that many long held "truths" in the homebrew world are actually not based in fact and are inaccurate (i.e. autotolysis, need for a secondary, ect.). While hand cranking 24 lbs. of grain this evening in preparation for tomorrows brewday (my drill burned up last brewday), I started to examin the crush that I was getting out of the mill. I was getting a fairly fine crush (corona style mill) and instead of adjusting things to compensate for the widely held belief that grain should be just cracked to expose the interior of the grain, I left it on the fine side. I think in Revvy's ugly corona mill thread he noted that he shoots for 1/3 flour, 1/3 large hull pieces and 1/3 whole cracked grain. I usually stick to this combination and have always had great success with no astringency issues. My question is this... has anyone every crushed their entire grain bill towards the four/ pulverized end of the spectrum on purpose, to see if overly crushed grain astringency is another one of the long held homebrew myths?

If grain astringency is a myth, could someone use rice hulls and their flour/ pulverized crush to get some amazing efficiency numbers?

Does anyone know where the supposed astringency comes from? Could the "astringency" be from flour making its way into the boil kettle (poor vorlouf technique) and the boiling of the grain flour be what causes the astringency?

Any thoughts?

I always thought that the astringency was from over sparging and extracting tannins from the husk. Which is one of the reasons BIAB guys can get away with a finer crush (no sparge).

Yeah. I tried it with a blender. Ground to very, very fine. I tried using a french press, it clogged in less than 1/2 inch of press. Tried letting it settle, got further but less than half way. Tried adding a bunch of rice hulls, three fist fulls. Mixed, settled... Still plugged. The wort eventually shot up the side of the glass past the mesh filter.

Good luck trying it on a large scale without pro equipment.

I ended up dumping it in a sieve, and pressed it out, scraping with a spoon to unclog the sieve while it drained.

My conclusion was not worth the effort.

Back in the day, I had a Corona and shredded pretty fine. Back then, I had no idea what tannic bite was or what the difference was between it and hop bitterness. My tastebuds were still green.........Rice hulls are just the hull. There's no grain in them. There is no need to crush them. They're used to help prohibit a stuck sparge. I now have a roller mill and still crush way finer than what I see in the pictures here. Different methods of brewing and the type of equipment used are the determining factors on what crush is the best......In certain brewing processes, for instance, decoction mashing, tannins can be released if attention to pH isn't considered. If sparge water is too hot or the sparge is over extended, tannin can be released. Just because certain things aren't as prevalent in certain home brewing methods, doesn't necessarily make them a myth. Crap happens when all the ducks line up.

My ducks seem to line up quite a bit haha