So my first batch was sampled after a week of bottle conditioning... a tart taste was reported and it sort of smells like a half drank beer that sat out all night. There are no visible signs of bacterial infection. Any ideas? Its the Mild Ale Extract from NB... Shouldn't have a tart taste... She said it was pretty decent however i come home to find the bottle half drank sitting on the counter. This is the curse of the brewer who doesnt drink I suppose.. having to rely on other's taste buds.