PH adjustments. Which chemicals are best?

dad

Some times the simplest stuff ...

A week ago this was half full of marble rocks ($3.5usd for 50Lbs). Ferment, 170g of sugar & molasses, self regulated and ate the marble as necessary. Stayed between 4.5-5.0Ph.

Fiji_Spirits

Well the coral is in paint strainer bags/netting. We had some laying around so... yup!

Put it in at the start. Dropped 1.5points overnight but still stayed about .25 higher than usual.

I added some sodium bicarbonate to bring ph up to 5. We’ll see if the coral can maintain now the initial crash is done. You can definitely see it bubbling away!!

Fiji_Spirits

As to the sodium hydroxide. After four days of additions to keep it around 4.75-5 it stabilized at 4.75 and is holding. Speed seems decent as well.

Fiji_Spirits

Quick update on this.

We tried coral and found it to work well. Cleaning pre and post ferment are kind of a pain and I worry that bacteria will be transferred into the new ferments because of the porous surface.

I’ve found a little limestone to try.

Also we have switched almost exclusively to sodium hydroxide. The ferments seem nicer as a result and the additions are much easer. So far the additional handling procedures seem to not be a significant hurdle.

Oswald

@Kapea said: Potassium hydroxide KOH has the same effect as sodium hydroxide NaOH without the sodium load (potassium instead)

Be aware - both KOH and NaOH are very dangerous to work with. Use of PPE is imperative. Eye protection and gloves are minimum PPE. A face shield and apron are also a very good idea.

One splash of KOH or NaOH in the eyes will cause severe eye damage. Splashed on the skin, you may not notice it right away. By the time you feel it much damage has been done.

That said, KOH is my fermentation pH raiser of choice. A little dab'l do ya.

I use NaOH to make soap.

I would agree if you want to be safe make sure you have running water in a hose when you do it, if the protective glasses are not there or defect (not covering everything) you will be thankfull. Skin and other thing can wait normally but not your eyes. But dont be overcausiuos, it will not jump into your eyes without a reason, but reasons exist.

JayTee

How much NaOH or KOH is needed to shift the pH a certain amount in a certain amount of wash please (just so I can make a comparison with my use of K2CO3). I'll be stepping up to larger wash volumes soon, so it would be helpful to have an idea

Kapea

How many angels can dance on the head of a pin?
The stoichiometry is a function of the reactants, where your pH is, and where you want it to be. pH change is logarithmic, not linear.

Mostly it's an empirical thing you're going to have to work out for yourself.

Fiji_Spirits

@JayTee said: How much NaOH or KOH is needed to shift the pH a certain amount in a certain amount of wash please (just so I can make a comparison with my use of K2CO3). I'll be stepping up to larger wash volumes soon, so it would be helpful to have an idea

In my sugar washes typically from 3.25-4.0 will take 100-125g. The higher the start ph the less it takes to make the same movement.

Compared to sodium bicarbonate it takes about half to 2/3s as much with zero foaming.

zymurgybob

@Fiji_Spirits said: In my sugar washes typically from 3.25-4.0 will take 100-125g.

100-125g in how big a batch?

Fiji_Spirits

@zymurgybob said: 100-125g in how big a batch?

200l

And it’s super variable too like kapea says. After a while you’ll kinda have a decent guess at it but about 40% of the time you’ll have to add more or add too much.

stevea

Calcium hydroxide (hydrated lime) is readily available in food-grade and avoids much of the yeast-stress caused by excess sodium or potassium.

JayTee

Thanks guys

stevea

@zymurgybob said: ... To lower the pH of the wash we put in the vodka still, for the purpose of driving the esterification equation away from ester formation, we use a small amount of sodium carbonate....

Uhhm - the Na2.CO3 increases pH thus producing more esters - right ?

zymurgybob

Ooops! Raising pH, yes (sorry). But that increased pH runs the esterification equation backwards, and reduces esters and therefore flavors.

JayTee

I've been trying to find a supplier of NaOH / KOH in the UK, and none of them are food grade. To be honest, I don't really know what "food grade" means but I've always managed to get it when I've used K2CO3. I have found Ca(OH)2 as food grade (stevea's suggestion).

A newbie question, but do do all these hydroxide options pretty much work as well as the others? If I go for Na / K then technical grade is all I can get. Thanks in advance for your comments :-)

Moonshine

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