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djsxxx
03-16-2016, 09:05 AM
I checked the Ph of my 19L batch this morning and found it had dropped to 3.2, which I believe is the bottom end of the yeasts limit before they become stressed.

I have some Potassium Bicarbonate already, but I have no idea how much to add to bring the Ph levels up.

Is there a formula or a way of working out how much to add per gallon/litre to raise the Ph say 1 point?

Also, once I have made the addition of Potassium Bicarbonate, how long does it take for the Ph levels to change?

Thanks in advanced!

Squatchy
03-16-2016, 10:15 AM
Used to lower acidity levels in wine. 3.8 grams per gallon will reduce acidity by about .1%

djsxxx
03-16-2016, 10:38 AM
Is that 0.1% or 1%

And is that % of current ph level.

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Farmboyc
03-16-2016, 01:05 PM
Remember that Squatchy is giving you the #'s for WINE and not mead. Mead has very little pH buffering and in my limited experience the pH moves more than wine.
I would suggest adding 1 tsp to your 19L and wait 12h and test. I way overshot on my first use and ended up with a pH of 6. The melomel lost most of its crispness and I ended up adding acid blend for balance.
Much more of a PITA than it needed to be.

zpeckler
03-16-2016, 01:37 PM
Used to lower acidity levels in wine. 3.8 grams per gallon will reduce acidity by about .1%
Squatchy, is that titratable acidity?

djsxxx
03-16-2016, 03:25 PM
I have added 1 tsp this evening, so will check Ph levels in the morning and see what's happened.

Farmboyc
03-16-2016, 05:11 PM
Potassium bi/carbonate should be used carefully due to additions increading must/wine pH (by the inevitable presence of increased potassium ions). Bench testing may be conducted on samples to ensure that the desired level of deacidification does not cause a pH shift beyond acceptable levels.

Approximately 0.67 g of potassium*bicarbonate*is reported to practically reduce the TA by 1 g/l (2.53 g reduces 1 US gal. by TA of 0.1 %; 3.03 g reduces 1 Imperial gal. by TA of 0.1 %).
Approximately 0.92 g of potassium*carbonate\ is reported to practically reduce the TA by 1 g/l (3.49 g reduces 1 US gal. by TA of 0.1 %; 4.19 g reduces 1 Imperial gal. by TA of 0.1 %) and raises pH by between 0.2 to 0.25 units.

Either chemical is usually added to the entire batch, carbon dioxide is given off while the batch is well mixed, and cold stabilisation but should be used before cold stabilisation so that full precipitation is achieved.



www.brsquared.org/wine

Just found this. Kinda explain the influence on TA and pH.

pwizard
03-16-2016, 08:54 PM
Does anybody know the effectiveness rate for calcium carbonate (CaCO3)?

Farmboyc
03-16-2016, 09:12 PM
Does anybody know the effectiveness rate for calcium carbonate (CaCO3)?
Hit the link in my previous post. It is included in the full article.

Personally I hate the stuff. It doesn't dissolve well and seems to take a few racking to get rid of. JM2C

EbonHawk
03-16-2016, 09:40 PM
Here's another thread with some info in it, although in it, someone states that carbonate is more potent than bicarbonate, but that doesn't jive with the numbers Farboyc posted above. So I'm not sure who's the one to go with right now...

http://www.gotmead.com/forum/showthread.php/12583-Potassium-Carbonate-vs-Bicarbonate?highlight=potassium+carbonate+bicarbon ate

Squatchy
03-16-2016, 11:46 PM
Is that 0.1% or 1%

And is that % of current ph level.

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Your answer is .1%

Squatchy
03-16-2016, 11:47 PM
Squatchy, is that titratable acidity?

No. It's pH, which is much different that TA. You can have the same pH with much different TA's.

djsxxx
03-17-2016, 12:02 PM
After the addition of 1 tsp I checked Ph the following morning, it had only raise to 3.4

Added another 1 tsp so will check Ph tonight

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Squatchy
03-17-2016, 04:00 PM
That's high enough. Your right in the pocket now. I wouldn't add any more.

djsxxx
03-17-2016, 04:22 PM
Just checked and we are up to 3.7

SG this morning was 1.046 about 12 hours later, after additional potassium bicarbonate, SG down to 1.040

Squatchy
03-18-2016, 01:27 AM
So we have learned the adjustment takes a while. I would suggest next time to not add the second addition. .7 is to to low and opens the door some to the bad guys. At 3.2 it is still keeping the bad guys at bay. The further away from that the less effective at doing such

Paladin906
11-05-2016, 12:32 AM
For what it's worth. Today my pH reading was 3.2. I added 2 teaspoons of KHCO3 which equaled 6 grams per teaspoon so a total of 12 gms. 10 hours later my pH equaled 3.99.

zpeckler
11-05-2016, 09:33 AM
For what it's worth. Today my pH reading was 3.2. I added 2 teaspoons of KHCO3 which equaled 6 grams per teaspoon so a total of 12 gms. 10 hours later my pH equaled 3.99.
Your active fermentation should be long finished by now... One fermentation is complete you don't have to worry about pH because the yeast are done working. At this stage, make all acid or bicarb additions based on the taste of the mead, not numbers. If it tastes good, don't mess with it.

I would taste the mead now. Adding that much bicarb at this point can knock out the acidity that makes a mead taste refreshing and balances sweetness.