I've brewed 2 batches so far and I'm getting a almost plastic aftertaste and even a slight smell of the same caliber. I'm at a loss as to why this is happening to my brews. I've done some searches and they all point to water. I used bottled water for both brews and as far as I'm aware, bottled spring water (arrowhead to be specific) doesn't contain any chloramines and doesn't require campden tablets or similar.
Both were extract brews. Different recipes, one was an Irish Stout and the second a Honey Kolsch.
I know I had the fermentation temperature a little high on the first batch so I thought that was the problem, I lowered the temp on the second batch to about 62 for about 3 weeks and had it about 68 degrees for the fourth week (US-05 yeast). Although it's not as strong, It still has the same aftertaste.
I'm usually pretty sensitive to any plastic taste in bottled water, this doesn't exactly taste the same but the closest thing to describing it. I tasted the bottled water pre-brewing and I didn't detect any off flavors.
Could it be the fermentation bucket? Both my brews were month long primaries in a plastic bucket I got from my LHBS.
First batch I just used a single pouch of wyeast so I suppose it's possible I under pitched but I don't think I under-pitched the yeast is the second batch, no starter since it was dry yeast... I re-hydrated per recommendations.
The only other thing I can think of is maybe pitching at the wrong temperature. I'm still a little fuzzy on exactly what that temperature should be.