Grainy, malty flavor in my apfelwein

So I put together a batch of apfelwein, based on Ed Wort's recipe of course, deviating in that I only made 4 gallons and used 2 lbs dark brown sugar instead of the corn sugar that was recommended. As a note, I used Kroger brand apple juice, ingredients: Filtered Water, Apple Juice Concentrate, Ascorbic acid.
It has been in the fermenter since Oct 31 at a steady 68ºF. Going into bottles Friday.
OG: 1.065
FG: 0.995

Anyway, as the title states, it has a grainy, malty type finish. My question is would this be caused mostly by my substitution of brown sugar or more likely by the apple juice that I used. Also, as it is still "young" , what are the chances that it will fade or develop during aging?

It will change a lot over the next 6 months. You won't recognize it by then. After 1 month I could not drink it. After 2 months I drank it but reluctantly, now it's more than 6 months and it is pretty good.