Keeving and need to lower ph how much malic acid to add?

[ronb...@gmail.com]

I am attempting a first time Keeveing project-...I have 4 carboys with 2 -5 gallon carboys and 2 -6.5 gallon carboys.  3 of these carboys are straight golden delicious juice with a ph of 3.8, a SG of 1060/brix-14.8  ----- the fourth carboy is a 60% mix of golden delicious and 40% cider and crab apple mix--SG 1070---PH 3.66 -- Brix 14.8 

all of these containers have been macerated over night, pressed and then Pectin Enzyme added, then 24hrs later the CaCl added.   The CaCl was added on 11/20/18 when the temp was 42degrees F.   The temps are being kept around 40 to 42 degrees F.     Claude's test with rubbing alcohol gave almost instant gel from the initial pressing of the  juice.   my Two 1/2 gallon jars of control juice at 52 degrees F is sprouting mold.

Chris Ryland is a saint who has been very helpful.  

But I need a bit of Claude or Andrew's chemistry skills to help me straighten up the mess I have created.  I should have  mixed in a more acidic juice before i added the enzymes and CaCL....but did not...At Chris's direction I have ordered malic acid to add to the juice to lower the ph.   it should arrive in 4 days.  

My question is=  On a gram per gallon basis-----how much malic acid do I need to add in order to drop my PH levels down to the 3.5 level?   I use a handheld Hannah to check my ph levels and always test in against a control solution.  I realize that i may need to mix, wait and test before adding more but have no idea what amount to start with.

Well, I hope I have given you wonderful folks enough information to help me help myself.   If I have left some valuable data out...let me know and I will try to supply it.

In Advance, thank you for your help.

ron b Idaho, USA

[Andrew Lea]

As i think you realise, it has been explained on this list many times over the years and indeed several times this season that there is no simple relationship between titratable acid and pH.  Hence it is impossible to give an exact answer to your question. Trial and error is the only way.

However, in practical terms, I would always think of addition in steps of around 0.1% or 1 g/L. That’s 3.8 grams per US gallon. If you get cold feet about that, then try just 2 grams per gallon.  After each addition, stir well to dissolve before re-checking the pH.

However, if the gel starts to form throughout the keeve before your malic arrives, the act of stirring may not be advisable because it will break the gel and interfere with the keeve and formation of the chapeau. In that case, I would wait until after you rack the clear juice away from the chapeau before adjusting the pH. In other words, just before the long slow fermentation begins.

The reason for adjusting the pH down a little bit is simply to minimise unwanted bacterial infection during fermentation, as well as to adjust the acidity balance of the final
product. I posted this link a couple of days ago http://cider.org.uk/pH_control.pdf

Andrew

Wittenham Hill Cider Portal
www.cider.org.uk

[Claude Jolicoeur]

Le lundi 26 novembre 2018 16:47:52 UTC-5, ronb...@gmail.com a écrit :

But I need a bit of Claude or Andrew's chemistry skills to help me straighten up the mess I have created.  I should have  mixed in a more acidic juice before i added the enzymes and CaCL....but did not...At Chris's direction I have ordered malic acid to add to the juice to lower the ph.   it should arrive in 4 days.  

My take on this issue is that there is no reason to panic because none of your batches have pH higher than 3.8.

Also, I would absolutely avoid disturbing the juice as even if you don't see it, the pectic gel is forming and any disturbance is likely to reduce your chances to obtain a good chapeau brun.

True however that your 3 carboys with pure Goldens are likely to lack structure and mouthfeel, they might be a bit bland. As Andrew says, you can add some acid when you will make the first racking from under the chapeau brun. Adding 1 g/L at that moment seems to me like a good strategy.

Consider also you can always increase the acidity later when the fermentation will be done and you taste the cider. You can then take a sample and add acid according to your taste until you think it is right, and you can add the same ratio to the whole batch. The more you have residual sugar, the more you will probably want to add acid to balance this sugar.

Claude

[ronb...@gmail.com]

Thank you very much for your continuing and always helpful advice.  I had missed your previous posting even though I had done a few searches looking for my answer.   I always read your book and Claudes before starting anything new...but inspite of the great help ...I manage to miss something...every now and then

you have got me on the right track.  Thank you.

[ronb...@gmail.com]

Thank you Claude for your help and time.  Your efforts, like Andrews are very much appreciated.  I will do my best to keep moving ahead. here.

Thanks.