Astringent or just over hopping?

I constently have had this debate in my mind whenever I try any of my new beers. Some, not all of my beers tend to have a harshness after I've swallowed. It's not really puckering by any means but I'm not entirely convinced it's hop bitterness either.

Until recently, my last 3 brews, I've started to brew using a 50/50 mix of RO and tap water. I do this mainly because I found using just my tap water hightened the harsh finish. I originally attributed this to being the Sulfates but according to my water report it's only 30ppm. Which according to Palmer is perfectly fine for brewing.

However when I received my first competition results back this past week one of the judges said my beer had some astringency to it. Thus confirming my thoughts. But! this was a beer I brewed while using 100% tap water.

The only beer I have in competition right now that used RO water is my Dunkle, which actually used 100% RO water with some Calcium added. It's for Toronto Beer week so I wont hear those results back from some time. I guess it's a good test. It's funny too, I taste absolutly no harshness to that beer at all... but then again my darker beers have generally been pretty good for that.

Which furthers my debate... maybe it's my mash pH. If my darker beers turn out with little to no astringency maybe it's because the darker malts lower my ph to within acceptable ranges.

Which brings me back to the beer i just kegged, "Oktoberfast". I used 50/50 RO/Tap water on this one. I did so because when my tap water is halved it is about 90% the same as Munich's water profile. This beer tastes great but then has a slight harsh finish. I mean very slight. After 2-3 sips of it, it completly disappears. This is making it even harder to discern if it's astringency or hop bitterness.

This post was probably all over the place but all this thinking of brewing water and pH has my head spinning like crazy. I just want a Definitive answer dammit! lol

 

I only use RO water and add salts per this
my well has so much iron in it I'm surprised that a magnet won't stick to the glass

 

My .02 is that you may be on in here. I noticed a similar problem with my beers...except for beers with darker malts (which are usually less hoped as well). I did two things: I started using RO water to ensure that no chloramine/chlorine was in my water, and I started adjusting said RO water for pH. I no longer have said astringent taste.