Adjusting the pH without shocking the mead yeast

[NeverDie]

I expect I'll be receiving my pH meter today, and I expect it will be telling me that I should adjust the pH on many, if not all, of the meads I have currently in progress.

If using potassium bicarbonate, are there any particular rules of thumb as to how best to change the pH without shocking the yeast? For instance, no more than x amount of pH change within t amount of time? Can a pH change be done at any point in the fermentation process, or only at the beginning (or maybe not at all if it has already started)? I realize it would have been better to change the must pH *before* adding the yeast, but that train has already left. I have about 10 different small mead/cyser batches going in various stages, from just started (one of which is off to a slow start using Wyeast Sweat Mead yeast) to having been fermenting 3 weeks (vigorous at first and now going slowly, each batch using a different yeast strain to test drive the strain and compare results). The OG's were generally about 1.106.

 

[Maylar]

What makes you think you need to adjust it?

 

[NeverDie]

What makes you think you need to adjust it?

I was reading here: https://www.maltosefalcons.com/tech/yeast-propagation-and-maintenance-principles-and-practices
that by buffering with calcium carbonate, the author was able to get his mead to finish fermenting in a week, compared to much longer without it.

It looks like all of my different batches will be taking much longer than a week--probably more than 3 weeks--which is why I'm now looking into pH as a possible factor. Many of them are cysers, so they're starting with apple juice acidity on top of the honey acidity. If a regular mead might need pH adjusting, then I'm guessing that a comparable cyser is even more likely to for that reason. Starting OG on all of them was around 1.106. Of course, I don't know what the author's OG was, so making a direct comparison is difficult. I'm assuming his were more or less "standard" meads, with a fair amount of honey in them, but I can't say that I know that for sure.

Obviously, I'm interested in a quick mead rather than a 2 year mead, where the extra few weeks would be tantamount to a rounding error.

 

[NeverDie]

I guess I'll just go with Pitbull's advice of adjusting at the rate of 0.5g calcium bicarbonate per gallon: http://www.gotmead.com/forum/showthread.php/21113-Low-pH-2-90
I suppose I'll have to boil it into a sterile water solution first just to make sure there's nothing living in it that will take over.

 

[Maylar]

No boiling.

Measure pH with your new toy and if it's above 3.4 leave it alone.
Cysers need a bit of malic acid bite for balance.

 

[NeverDie]

No boiling.

I was curious as to why you would say that, so I tried looking it up. According to this: https://www.henriettes-herb.com/eclectic/kings/potassium-bica.html
potassium bicarbonate becomes potassium carbonate after boiling it. Does that transformation somehow make it more acidic? I mean, gram for gram it would be, but it would weigh less after the transformation. Not sure how to evaluate that. I guess I could try measuring the pH with my "new toy" before and after boiling, and then I'd know.

Hmmm... Some people seem to prefer potassium carbonate for making their pH adjustments because it can raise the pH in less time. So perhaps it would actually be an upgrade?

 

[Blacksmith1]

I think he means don't boil the meads as it will kill the yeast.

 

[NeverDie]

I think he means don't boil the meads as it will kill the yeast.

Oh, well if that's what he meant, it wasn't what I was planning. I just meant to boil the potassium carbonate in a small amount of water to make sure I wasn't inserting anything living into my mead must.

 

[Maylar]

Actually I was talking about the carbonate. Every time I've used it (in BOMM's) I've just thrown it in dry. If the instructions say otherwise, then never mind me.

 

[NeverDie]

The pH turned out to be 3.63, so I don't think it's the issue. I'm going to pitch more yeast at it and see if that makes a difference.

 

[Brett_Bellmore]

Oh, well if that's what he meant, it wasn't what I was planning. I just meant to boil the potassium carbonate in a small amount of water to make sure I wasn't inserting anything living into my mead must.

I'm pretty sure that there won't be anything living in the potassium carbonate, if you mix it up as a saturated solution first. That would be a ph of 11.5 or so, pretty high. Even Alkaliphiles (Bacteria specifically adapted to high ph.) would find 11.5 tough sledding.

 

[NeverDie]

I just now looked it up on google, and the pH of potassium bicarbonate, which is what I have if I don't boil it, is 8.2

I suppose this might be an argument for starting with potassium carbonate instead. i.e. possibly no boiling required.