I have searched through the forum, and contacted my local home brew store, but I cannot find an answer for this question. My first 3 batches (kits), were fine, but my last 4 batches have had a sour taste. I compare it to how tea tastes when it spoils. I took 2 different brews to my home brew store, and they told me it was the cascade hops giving the sour flavor. My og and fg are all on target. My beer is carbonated well using dme instead of corn sugar. My last batch, using fuggles, tasted great at 1 week, but at 2 weeks, I detect the sour note. Caps, oxidation, improperly sanitized bottles? Help!