I've done a bunch of BIAB batches and I find that the post that you quoted is full of BS.
BS, really? This post is a classic example of why I don't post here very often. A great brewer should be full of doubt, not dismissive and ignorant like this.
That advice is based on well thought out and valid points brought forth by years of anecdotes of many BIAB folks. Your experience is, well ... not enough data points coupled with unknown variables. As I said in my post, "fine" can mean anything. I do not argue that a finer crush can have its benefits in some cases.
The take away from my post should be that a brewer should be cautious as to how "fine" they crush. It lists the potential dangers, and encourages the brewer to apply the information to their own conditions. How that can be "BS" is beyond me.
That post does not imply that somebody like yourself has not, or will not experience a jump in efficiency due to a finer crush.
If you want to extract the most sugars, you have to get the particles of grain down in size so that they will wet through.
The crush described in my link has produced great efficiency for many brewers under many different circumstances, for many years. Perhaps you can confirm this by opening the gap on your mill and gathering more data points?
Maybe you are settled and won't fix what is broken? This is fine, but ..
The scientific method demands that we not become complacent with conventional wisdom found on a brew forum at any given time. How will we grow, how will brewing expand?
If you don't get all the starches wet, the enzymes don't break the starches to sugar so you leave a lot of potential sugars behind. You can compensate for part of that by mashing longer but there is a limit to even that where the grains simply won't wet in any more. By milling fine, you expose the most percentage of the grain kernel to the water, you wet them through quickly, the enzymes then work on the starches, and you are able to get the sugars leached back out. I notice a change in my efficiency in one batch and traced it to the adjustment on my mill that had loosened so my grains weren't milled as fine. When I adjusted it back, my efficiency came right back up.
One batch. I don't know, I'd be skeptical by placing so much value on a single batch. There are too many variables in brewing, and even the most careful brewer can miss something.
I think you are creating a false dichotomy here. There is merit to your words, but there is a happy medium. It's not so black and white.
You don't have to double mill or crush super fine to achieve what you are saying here. There are many levels of crush that will produce the same results as a very fine crush (without the potential issues mentioned previously). My last post mentioned "potential" dangers that a brewer can face by obliterating a grain husk.
Perhaps you would not have these issues if your mash pH was in check, and your temperatures were reliable. That's fair enough, but that's not everybody else.
I like to step back to think of other brewers who may be brewing with water that hasn't been worked out yet, and also equipment such as thermometers that might not be reliable as they think. The potential dangers of a finer crush increase depending on the brewer and their experience level.
This is why all of our own individual experiences do not hold as much value as we would like them to. I agree with your points, but do not respect your view of the BIABrewer post, like ... at all.