The more I look. the more I see it. I started brewing (again) about 18 months ago, and for the first year didn't notice it. Then I started noticing that some bottles had a haze on them after pouring out the beer that doesn't clear with rinsing. The beer is crystal clear. Now it seems that almost every bottle has it.
The haze forms on vertical surfaces, if the surface is inclined down (such as the neck) it doesn't have the haze.
I ignore it on some bottles, but mostly I soak them in a dilute solution of bleach which I keep my hoses in. Not too much of an issue, but just an extra step.
Would like to understand what it is, would be nice to see if I could eliminate/minimize it.
Is it due to hard water, or something to do with yeast? I get it in ciders too which don't have much added water.
Since finding it in my beer, I've started finding it in commercial beers. I found it in a couple of bottles of Sam Adams (had to look hard), and a few weeks ago, I had 5 bombers of Rouge 'Yellow Snow' in which it was obvious, and really made the bottles opaque.