New cider maker - PH problem

So I’m new to this process, and I have 2 batches already in secondary. I could use a little amateur/professional guidance concerning the second batch. I purchased 10 gallons of pasteurized cider from a local orchard at one time. I started the first batch and then about 3 weeks later I started the 2nd batch, and those 5 gallon plastic jugs had started to inflate in the while they were sitting in the fridge, I believe they were beginning to ferment on their own in the fridge. The cider tasted a little carbonated or fizzy. Both had White Labs English Cider yeast, nutrients, campden tabs to kill off native yeast, and pectin clarifier added. Only difference between batches was storage time in fridge and batch 2 had brown sugar added, about 3 cups.

Batch # 1: put into secondary on 11/5, and I’m almost ready to end fermentation and back sweeten before kegging. It has a pH of 4.2 and titratable acid level of between .65-.75 with a SG of around .95-1.005. Tastes like dry white wine.

Batch # 2 is also in secondary, same cider purchase (pasteurized from a local orchard, but with a pH of 4.5 and titratable acidity of .9. This batch tastes different, not foul or oily but not like vinegar either with a SG of 1.005-1.0.

Question, how concerned should I be about batch # 2 with a pH of 4.5 and now that it’s been in secondary since 12/7 can I or should I add malic or lactic acid at this point to improve the pH or is it a moot point?

Thanks, and happy New Year!!

Both batches seem like they are in the “normal” pH range for ciders, I wouldn’t worry about it. Post fermentation pH is pretty much a moot issue anyway, I would only add acid if you think it needs it for the flavor. Take out a small sample and experiment with that before adding anything to the whole batch.

There is something strange about your cider as well. The jugs you stored in the fridge were obviously starting to ferment on their own, but if they were pasteurized they shouldn’t have.

Thanks for your comment! That’s what I thought, but the orchard said it was a state requirement in Maryland that all cider had to be pasteurized.