Potassium Carbonate

[NinjaBear]

When used to adjust pH balance, does it impact flavor?

Can too much kill your yeast?

How effective is it as an alkalizing agent?

Would Calcium Carbonate work as a substitute? (It's a bit lower in pH, but more readily available to me.)

 

[Yooper]

When used to adjust pH balance, does it impact flavor?

Can too much kill your yeast?

How effective is it as an alkalizing agent?

Would Calcium Carbonate work as a substitute? (It's a bit lower in pH, but more readily available to me.)

I've never used potassium carbonate, and only used calcium carbonate so I can't compare them. Calcium carbonate works fine for my purposes.

 

[Twerp129]

I've only ever used Potasium Bicarbonate on a large scale, I would imagine it to be extremely difficult to use on a small scale where you need to use extremely small doses. Calcium Carbonate may be easier on a small scale.

 

[Mr_fleabite]

I do not have any experience with Calcium Carbonate.
Potassium Bicarbonate is typically used in the industry. The formulas that say add X amount for a 0.1PH shift don't seem to hold up in the "real world". In my experience bench top trials are needed for every addition to increase PH, along with an accurate way to measure your outcome (TA & PH); otherwise you're just doing it to taste (which may be all you need/ want). To do the addition properly (with any accuracy) you'll need a scale that gives accurate fractions of a gram 1/10ths place should be sufficient.
For my benchtop trials I start with .2, .4, & .6 grams in 400ml samples I'd then expand this to my batch size based off taste AND analysis.

The hardest part about doing this is the small amount of material that you'll need and accurately weighing it.

 

[IJesusChrist]

In mead, honey has an acidic pH and fermentation further lowers pH. Thus KHCO3 (potassium bicarb) become an essential nutrient/additive in making mead fermentation quick and smooth.

We tend to use ~1 tsp/5 gallons.

However, the originator of the BOMM (Bray) mead has used 3/4 tsp for 1 gallon. He swears by it. Potassium bicarbonate isn't going to impact flavor much directly, however, with low pH worts, it may increase yeast fermentation activity and cause less stress.

Potassium by itself has been shown to increase yeast alcohol's tolerance as well, increasing ABV's achievable with most strains.

The effect of potassium as a supplement to one's water chemistry (Aside from that stated above) I am unsure of!

Potassium bicarb and potassium carb are different! They will have different impacts on pH with the same mass of additions (or mols)!

 

[IslandLizard]

In mead, honey has an acidic pH and fermentation further lowers pH. Thus K2CO3 (potassium bicarb) become an essential nutrient/additive in making mead fermentation quick and smooth.

We tend to use ~1 tsp/5 gallons.

However, the originator of the BOMM (Bray) mead has used 3/4 tsp for 1 gallon. He swears by it. Potassium carbonate isn't going to impact flavor much directly, however, with low pH worts, it may increase yeast fermentation activity and cause less stress.

Potassium by itself has been shown to increase yeast alcohol's tolerance as well, increasing ABV's achievable with most strains.

The effect of potassium as a supplement to one's water chemistry (Aside from that stated above) I am unsure of!

Potassium bicarb and potassium carb are different! They will have different impacts on pH with the same mass of additions (or mols)!

Both can be used interchangeably for the same results but you will need to adjust the amounts. 1 gram of kcarb =/= 1 gram of kbicarb!

Potassium Bicarbonate is KHCO3. Similar to "Baking Soda," which is the Sodium version of it. Besides for adding some alkalinity it can be used to raise the pH. It still leaves a flavor residue if used in larger quantities, IIRC.

Potassium Carbonate is K2CO3, comparable to washing soda. Quite alkaline and nasty tasting.

 

[NinjaBear]

Great information.

To achieve the end product I want, I need to alkalize my batch. This has been very helpful.

What is the upper limit to the pH yeast can tolerate?

 

[IJesusChrist]

Potassium Bicarbonate is KHCO3. Similar to "Baking Soda," which is the Sodium version of it. Besides for adding some alkalinity it can be used to raise the pH. It still leaves a flavor residue if used in larger quantities, IIRC.

Potassium Carbonate is K2CO3, comparable to washing soda. Quite alkaline and nasty tasting.

You're correct! My bad.

"Besides for adding some alkalinity it can be used to raise the pH."
It's slightly basic. IT would only raise the pH of highly acidic media.

 

[IJesusChrist]

Great information.

To achieve the end product I want, I need to alkalize my batch. This has been very helpful.

What is the upper limit to the pH yeast can tolerate?

Well, yeast are acid tolerant but can also grow in neutral conditions. You're likely to have an acidic medium when brewing though.

If your pH is from 4.5-6.5 you are going to be ok growing the yeast, but the pH is going to be an indirect indicator of other factors. The pH indicates acids and bases present. A pH difference of 1 indicates a 10x difference in dissolved H+, which means you may have 10x different concentration of acids/bases. That is going to impact your flavor profile. I'm not a beer expert, so I'll let others speak from this point.

 

[Mr_fleabite]

Just remember that raising your PH makes SO2 less effective and creates a better environment for bacterial growth (not a guaranteed outcome but just be aware, if you move it alot).

Out of curiosity do you know your current PH or how much you want to shift it? what is the medium/ fruit you're working with.

 

[NinjaBear]

Actually, I'm working with a high concentration of anthocyanin. Which is kind of a natural pH indicator.

It's currently pinkish red, which indicates a acidic environment. (Expected of the fermenting environment)

I'm hoping to get the finished brew to be blue. But that requires a neutral to slightly basic environment.

Although, too much will actually shift it green. (As you can see in the proof of concept sample.)

I'm also wondering if I might need pectin enzyme to clarify it.

But since I couldn't find any indication that this was tried before, I'm kind of in uncharted waters and mostly making it up as I go.

 

[NinjaBear]

Those samples were magnesium and sodium bicarbonate respectively.

 

[IslandLizard]

Why exactly do you want your mead (?) to be at pH7 or above? Isn't some acidity good?

Did you add anthocyanin to the whole carboy? Is this a science experiment or a prank to get people to drink blue or purple mead? I'm puzzled.

 

[NinjaBear]

I extracted the anthocyanin naturally when preparing the batch before pitching the yeast.

And yes, it's entirely an experiment to see if I can make blue alcohol without needing to add a ton of artificial colors.

 

[Mr_fleabite]

Interesting idea, and I wouldn't begrudge anyone experimenting, it's the fun part!

I would caution that heading toward a neutral-ish PH is asking for some wild bacterial problems. Will this be fortified with high alcohol? will you have any residual sugars? Do you have a way to sterile filter? If you're planning on using SO2 you'll need a high concentration at PH's above 4.0, if you're taking the PH near 7 I'm not sure you'd have an effective SO2 level without leaving a heavy SO2 aroma (hence the sterile filter/ RS questions).

As far as clearing things up goes you could use pectic enzyme or bentonite (bentonite is a bit more effective when used during fermentation rather than after, but works well pre or post ferment).

In any event get your brew (whatever it is?) cold & SO2'd quickly after fermentation, this will help with settling and preventing bacterial growth. I'd recommend doing your PH shift post ferment. Also not sure if you were planning on Malolactic fermentation or not; if not you may consider adding Lysozyme this will inhibit some bacterial growth (but not all).

Curious to see where this goes, let us know what it tastes & looks like when it's done.

 

[IJesusChrist]

Change the pH after you've stabilized. No reason to adjust pH to get a color during fermentation since the pH will change over the course.

Having a neutral wine/mead will change the taste quite a lot. Most of the flavor profiles of any fruit-based wine is based off of acid components.