A few questions. (Tusch's recipie with a few changes)

I used Tusch's recipie.

Primary Recipe is as follows:
4.75 gallons Apple Cider
2 lbs. Frozen Blueberries
Whole pack of Craisins
2 lbs Light Brown Sugar
2 Cans Apple Juice Concentrate
Cider Activator Wyeast
1lb of white sugar
4 cans of blueberry pie filler

SG for Primary 1.078

Secondary:
added 5 pounds of blueberries
62oz blueberry juice
.5 gallon of apple cider
1 can of blueberry pie filler

Gravity at transfer to secondary .900.

My question is why did my yeast go so far? I just transfered so i do not have a final gravity. Is there is a chance that this will start back up and drop further? And what could i use to back sweeten if needed? Tasted like wine when i sampled. I was looking for a sweeter taste, but I just had shoulder surgery and couldnt get to it quicker to take it off the yeast. Lol Im hurting now but had to transfer it.

It dropped to .990, which is what I assume you meant, because you boosted the ABV to around 10.4% making it more of a wine than a cider. Once fermented, all you have left in solution is water (SG of 1.000) and alcohol (SG of .789) bringing the final SG to less than that of water. Since all the ingredients in this recipe are simple sugars the yeast can easily convert everything to booze leaving no sweetness left for you. Now that you added even more sugars for the yeast to eat, it start fermenting again and the SG will end even lower and taste more wine like.

If you want a sweet final product you'll have to prevent the yeast from eating more by either stabilizing with sorbate and sulfites, pasteurizing, adding more sugars until the yeast reach their alcohol limit and die off, or adding unfermentable sugars like spenda depending on your final goal.

Yea thats what i meant (.990). Its does taste like wine right now. I just added a can of concentrate also. Im going to have to backsweeten with a nonfermentable sweetener. Ill check out the ones at the store (splenda or truvia the ones im looking at). Prob let it stay in the secondary for two weeks and then drop them in bottles. I will be making it sparkling and will add another can of berry concentrate at that time. Does anyone see something thats wrong with my plans?