I've brewed a few batches of NEIPA with varying success. The ones that I did not like had rubbery, hot Band-Aid, medicinal smells and sometimes tastes to them. As bad as that sounds, they were still drinkable and I even had some people claim to not pick up on that stuff (yes, maybe just being nice). For a while now I was thinking it was the Simcoe. All these batches had Simcoe in them and I drank some commercial examples that, to me at least, showed similar characteristics. In between these batches, I brewed some Hefes, a Kolsch, a couple Saisons, and a cider and they all came out fine so I am assuming my procedures, cleaning, water, etc. are decent. It's something to do with IPAs. I searched on these forums a lot and was able to find a few examples of BAs expressing similar woes with their IPAs. I think there was some poor guy who gave up brewing them altogether!!! I hope he's recovered since then. "Hop burn" was a common theme in a lot of the threads. I guess we can get this when using excessive amounts of hops in our beers. However, there are BAs using incredible amounts of hops and claiming continued success. Other theories blame certain varieties. I was (and still kind of) convinced that I simply discovered that Simcoe gave me these unpleasant smells/flavors. I bet if I drank a Tree House beer with Simcoe in it I wouldn't feel the same though. I brewed a few batches with tiny amounts of Simcoe and still got these off smells/flavors. I started thinking about the IPAs/NEIPAs I brewed that I loved. One difference I noted was the use of some kind of hop filter for my hop additions. When I first started brewing, I would always use muslin hop bags. The disagreeable smells and flavors starting happening when I started going commando at all times. I felt that going commando was the best method because you would get all that you could from the hops. They'd dissolve better and swim freely in the wort. But at the levels I was using (12-16oz per 5 gallons), is that too much for commando? @invertalon You've had great success with your NEIPAs and I know you use HEALTHY amounts of hops in your beers. Do you use a hop spider, muslins bags, etc. or do you go commando? For all - kettle additions, WP, fermentation/biotransformation hops, DH, etc.? Another area that I thought could be a factor is pH. We know pH is important for brewing beer but is it even more important when using a large amount of hops? I'm reading about it now and I think I'm going to need some time to absorb what I'm reading. I understand a lower pH results in a generally livelier and crisper beer and a higher pH can result in a dull-tasting beer but I know there's more to it than just that. I have a cheap-o $15 pH meter that I've use a few times but I think I need to find a way to measure my pH accurately for every brew that I do. Is it possible I'm over acidifying my mash and that could result in these flavors? I use Brewcipher. I know the mash pH calc is just an estimate and I should take my own reading to confirm but I use 10% Phosphoric based on Brewcipher's estimates. Lastly, while reading about pH I came across an interesting technique for the first time - The reduction in solubility of hop acids can be seen during fermentation. After wort is pitched with yeast and the pH falls during fermentation, most of the unisomerized hop resins will come out of solution again. They become part of the brown gunk that floats on top of the Kraeusen which, if a smooth bitterness is desired, should be removed via blow-off tube, skimming and not allowed to fall back into the beer [Narziss, 2005][Kunze, 2007]. Based off of the above, if I'm going commando with 12-16oz of hops per 5 gallon batches, could these unisomerized hop resins that fall back into the beer be the culprits to making my IPAs harsh and rubbery/medicinal? Also wondering if any of you engage in this technique of extracting this "brown gunk" from the Kraeusen. If so, how do you do it? Sanitized SS spoon? Sorry for the long post. I was ecstatic with a few of my NEIPAs and I'm trying to get back to that point. Thanks for any responses. Always love hearing what you guys have to say.