Questions on Acidity in Cider

[slanderkin]

I've been using store bought unfermented apple cider for a while as my base juice and have always had a feeling its not had the correct acidity for hard cider but have not yet figured out the best way to fix that. I bought a TA kit and a PH meter and did some testing on two fully fermented batches I had done recently.

I found that both of these had a TA(malic) of about 4.7 g/L with a ph of 3.67 an 3.6 for each batch respectively. I've read some of Claude Joclicoeur's work on acidity but was left a little confused on whether he was referencing acidity before or after fermentation, or even how much acidity changes during fermentation. My questions are:

1. What is an ideal PH/TA(malic) range for a cider before and after fermentation?
2. How much does acidity change during fermentation?
3. Is it better to alter acidity before or after fermentation has completed?

I am hoping to enhance my cider by understanding its acidity better (and eventually mixing apples for my own juice blends once I understand acidity) so any help/guidance is greatly appreciated!

 

[Yooper]

I started using Lalvin 71B for malic-acid high musts, and that works pretty well since that yeast metabolizes something like 30% more malic acid than other yeast strains.

But without a good mix of bittersharps, sharps, etc, it's more of a guessing game to try to get it right if the cider is pretty sweet and not a good mix for hard cider.

 

[Raptor99]

I usually aim for a pH of 3.4 to 3.5 for my ciders. For cider from grocery store apple juice, I usually need to add some acid.

I don't use 71B if the acid is right, because I don't want to reduce the acidity. I do the initial pH adjustment before fermentation begins. After fermentation, any acid adjustments are primarily to adjust the flavor.