How to adjust acid

jnesselrode

Hello all,
I have a 5 ½ gallon batch of cider going right now. It started as pasteurized cider from a local cider mill. I've made this particular recipe before but I'd like to up the tartness a little. I added 1 teaspoon acid blend at the beginning per the recipe, and the pH after that addition was 4.4. Based on what I've read, I'm thinking I'd like to have it down into the low-mid 3 range. It will be fermented out dry. I know there are other ways to measure acidity, and other acids to add, but I'd like to go with pH and the acid blend I've got. I'd like to get a ballpark idea on how much to add to lower the pH to that level, or a little above, without doing a whole bunch of teeny additions and retesting each time. I'll probably do tastings too.
Sorry if this question has been asked a bunch of times, but my search didn't turn up anything like this. Any help is appreciated.

Chalkyt

Firstly, it sounds like your local cider is mostly eating type apples which typically have a pH around 4.0 (and a Total Acidity in the order of 3 g/L or 0.3%). At least that is my experience with eating apples like Red or Golden Delicious, Pink Lady, Fuji, Gala, Granny Smith etc. For many of us, we can't easily source traditional cider apples that might have characteristics different to those numbers, so we work with what we have and sometimes need to add acid to boost cider made from this type of apple (TA is what you taste).
One gram per litre of malic acid (about a teaspoon per gallon) will raise the TA by 0.1%. Acid blend should do something similar so your initial teaspoon in 5-1/2 gallons won't have changed things much. Coincidently, my experience is that 1g/L of malic acid also reduces the pH of typical eating apple juice by roughly 0.2 (However, be aware that the effect of other acids can be 10% different to malic acid).
It might sound scary, but an acid titration kit from your local supplier is reasonably easy to use and will give you some idea of the relationship between TA and pH for your apples.
As an example, a recent 10 litres (a bit over 2 gallons) batch of cider (Pink Lady, Golden Delicious and Granny Smith) had an OG of 1.050 and pH 4.0. Adding 2-1/2 teaspoons (1.5g/L) of malic acid resulted in a pH of 3.6 and TA of 6g/L (0.6%) which is just about where I wanted it.
Try doing some acid adjustments to a small sample (say 100ml or 1/2 cup), taste, then extrapolate this up to your whole batch.
Hope this helps... Cheers!

jnesselrode

That does help -- thanks.