Medicinal/Plastic-Like Smell

I brewed a brown ale last month and kegged it up almost 2 weeks ago. I was out of town the whole first week it was in the keg and didn't get to try any of it until I got home on Friday and it smells not good. It has a plastic, medicinal, smell and I'm now sure where to pinpoint the problem. This is only the second dark beer I've brewed and this is the second time I've had this problem. Last year I brewed an OctoberFAST Ale and didn't get around to kegging it until this past spring. I figured sitting in a better bottle for 8 months had something to do with the off flavors in that batch. This one sat in the fermenter for 17 days and then I kegged it. I had read that chlorine could be a contributing factor but I sanitize with StarSan and according to my Ward Labs report I have 90 ppm of chlorine in my water.

Smoke will do it too... Not likely in my experience but any chance
You got smoke Around your fermenter or grains prior to or during mashing?

I had this occur on two batches.
I narrowed it down to something funky going on with some O-ring on the keg.

I relpaced the O-rings (all of them not just the big lid one) on the keg and tried a third batch and this one was fine.


If its been the same keg, I'd suggest changing all the rings and see if that helps.

Carb some water to test so you don't waste more nectar.