I'm not an expert being all of about 6 batches in myself, but the bottles I just tasted today that were way young have been my best yet. I can't say exactly why but I do know I did a way better job with temp control during fermentation, pitched my yeast at a lower temp, and didn't use tap water.
The water in our area is hard and heavily chlorinated (at least compared to my previous residence). At least where I live, there are water stores* and vending machines on every corner.
* The tap water where I live is perfectly okay to drink, but the large Mexican population in the area is naturally skeptical. Thus, we get purified water stores in every shopping center. As a brewer, I'm not going to complain. Water for .25 a gallon is an alright deal.