pH Buffer for TPW

gizzer48

I'm having issues with the fermentation crashing as the pH drops from around 5.5 to 3.0 it grinds to a halt , anyone used sodium citrate or anything similar to create a stable ph throughout?

crozdog

I have bought sodium citrate & citric acid to make a buffer - just haven't got around to it yet.

lots on info online eg How to Make a Citrate Buffer

White there are online calculators - a lot of them talk about adjusting the PH with NaOh which isn't something I want in my wash. Have a look at

Buffers - From Ruzin, 1999. Plant Microtechnique and Microscopy

as it has a table of the ratio's of 0.1M solutions of Sodium Citrate & Citric Acid to use to make a CITRATE BUFFER from PH 3.0–6.2

Kapea

There's nothing wrong with using NaOH in your wash. It dissociates into sodium ions and hydroxide ions in the solution of your wash. If you use a large enough dose the wash will have a salty flavor, but it won't carry over into the distillate. If you use a large enough dose to create a salty flavor in your wash your pH will be around 14.

I use 8N KOH for raising low pH in my washes and meads. KOH and NaOH are very similar chemically. A few milliliters of 8N KOH in a 25L batch will raise a high 2 range pH to a mid 4 range pH.

grim

Very interesting, I'd love to know how this works. I've always been kind of old-school on this, focusing on the source water chemistry first. Your water chemistry is going to make up a big portion of your buffering capacity.

I remember reading a brewing water chemistry site a year or so back that had a great tip on the ordering of salt additions.

Quickie Water Chemistry Primer

(Epsom, Gypsum, Bicarbonate, Sodium, Chalk)

Some great tips and easy to read. I'm sure even simple epsom salt and gypsum additions would go a long way.

Alternatively, other than being an absolute pain, why not add small daily additions of sodium bicarbonate (baking soda) solution throughout the fermentation? You aren't necessarily trying to halt the pH change, only slow the process and increase the terminal pH to the point at which you aren't halting the yeast. Usually it only takes 2 or 3 adjustments and the pH will steady because of the bicarbonate (buffer) additions. I wouldn't recommend making a big jump due to yeast stress - maybe a half point, a full point max, at a time.

rossco

@crozdog, that is what I use. Had good results with 48gm citric n 90gm sodium citrate in a 60litre wash.

Sadi

do we have info on starting and ending PH @rossco ?

rossco

Sorry Sadi, I did but I can't remember. I'll measure next time I make a wash. The measures were calculated properly, but I've been using these for a while.

Sadi

Thanks @rossco

actually, I have been practicing what grim suggested, adding small daily additions of chalk and baking soda. I usually keep the PH of my washes below 4 and higher than 3.5 for flavored products.

I wonder if targetting a certain level of PH, not a range, for the wash is a path to follow.

Cheers.

gizzer48

200 litre tpw fermenting very Nicely I added 1kg citric acid + 1kg bicarbonate soda before pitching yeast three days in and the ph is a rock steady 5.1 so seems to be working well

FloridaCracker

Being from the states I am a little rusty on my metric system but did you add 1 Kilogram of citric acid? Isn't that about 2.2 pounds?

rossco

@Sadi said: I wonder if targetting a certain level of PH, not a range, for the wash is a path to follow.

Sadi I am not sure if this is possible. The pH will drop naturally as the ferment progresses, so you would need to adjust it every day. I ferment mine for a month at least and mescal for double that. That said, I think pH is really important for the final product, and I recon I can tell the difference.

@FloridaCracker said: Isn't that about 2.2 pounds

Yep and the buffer amounts look right.

gizzer48

Florida cracker Yes it is 2.2 lbs of each compound , I have tried less of each at first but with no success but now i think this is the sweet spot for a 200 ltr wash, after a bit of experimenting hopefully ph stays stable until completion I will keep you posted on it my friend.

grim

I'm just surprised it doesn't turn into a volcano

FloridaCracker

My washes are only 120 liters but if I put 2 lbs of citric in them it would eat a hole in the plastic barrel. I add 3 tablespoons to mine.

Kapea

@grim said: I'm just surprised it doesn't turn into a volcano

This is what happened the last time I mixed citric acid and bicarbonate...

Smaug

@Kapea said:

Thunder head.

Kapea

@Smaug said: Thunder head.

Nope, Calbuco Volcano, Chile:

https://www.youtube.com/watch?v=ljrDn3Gel4M

Sadi

@rossco said: I think pH is really important for the final product, and I recon I can tell the difference.

+1

Cheers

gizzer48

I always mix the the two together in a separate container and let the reaction take place then once it has finished pour the sodium citrate into the fermenter