Punishingly dry cider

Made my first 5 gallon batch recently. Initial ingredients were 4.5gal of apple juice and 6 tubes of concentrate. All was well and good and at 1 month it tasted like a pretty typical young cider.

Bottled about 4 days ago with 5 more tubes and 1 cup of maple syrup. In the past I've had very good luck with small batches using these proportions. The results are mellow and sweet. BUT...

Tasted one tonight and BLAM. Like biting a crabapple. So my question is, what happened? did I just use too much concentrate? Did all my bottling sugars go to alcohol in just 4 days? Is this something time will fix?

Yikes!

I made a straight AJ cider with Nottingham yeast 3 months ago. I bottled it 2 months ago, and it is just now *starting* to get good. Ciders and apfelwein seems to hit their stride after about 6 months. It takes that long for the acids and the alcohol to really mellow out and to let the apple flavor resurface.

That's reassuring. I've had to deal with the fusel "rocket fuel" taste before but this is totally different. I'll pasteurize in the next couple of days and see how it pans out.