Had an OOPS moment with cider.

[NitrogenWidget]

2.5 gallons Aldi apple juice
Premier Blanc
2 walmart frozen apple juice concentrate for sweetening.

So I fermented it out and sort of forgot about in my fermentation chamber for a few months in the primary.
Tasted good but dry so I just racked it into my keg and added 2 cans of frozen apple juice concentrate. tasted awesome.
Sealed it up, purged it and stuck it on some CO2 in my then upper 50's/low 60's degree basement.

A week later I realized I forgot to add campden tabs and sorbate.
gave it a taste and it wasn't that sweet anymore and kind of bitter.

added campden and sorbate, waited a day then added another can of frozen.
It's a week later and it's sweet but still has some bitterness.

I assume I basically have to treat it like a new cider since adding the frozen concentrate caused it to start fermenting again?

Or did I do something bad?
Thanks.

 

[bernardsmith]

Not anything obviously bad but I don't know any frozen concentrate that tastes good. THAT might be the cause of your problem... (apart from using juice that was designed to be used as a sweet non alcoholic drink so the tartness may be emphasized to balance the sweetness. Remove the sugar and replace it with alcohol and there is not a lot to balance the tartness. One thing you might do is measure the TA. You want the TA to be about .6 g/l. much higher and the cider may be too tart.

 

[MarkKF]

I bet it all has ascorbic acid. That will leave a bitterness when the sugars are gone.

Make your own apple juice concentrate. Freeze fresh pressed juice then let the sugary syrup drip out as it thaws. Flush the watery ice that remains.

 

[NitrogenWidget]

First time I tried using concentrate to sweeten.
Originally it tasted amazing.

Previous batches I used sucralose to sweeten but I wanted to get more of an applely taste this time around.