Mead - pH & acidity

[Adam_Langman]

Hi,

I've been reading about the importance of pH and acidity when making mead... and, I'm a bit confused.

Some say to add acid to get around 0.65% acidity (blend of citric, malic and tartaric acids).

Others say to add a buffer such as potassium carbonate to raise the pH to keep it between 3.4 and 4 (various opinions) during fermentation to help the yeast.

Combined, the advice seems to be add acid to increase the pH... I trust you can see the problem here. I've simplified the issue but it's what I'm having a problem with.

So, what's the most important thing here, pH or acidity?

Is it a matter of a staged approach? For example, During ferment - Keep the pH between 3.4 and 4 by adding acid/base as required; then, at the start of maturation add acid to get roughly 0.65% acidity (essentially "to taste")?

Help appreciated.

Thanks,

Adam

 

[MHB]

I think you have gotten something arse about.
Adding acid will and can only lower the pH.
Adding Base will and can only raise pH.

The problem is that organic acids are what we call weak acids so the relationship between pH and "Acidity" isn’t direct as it is with strong acids, as they don’t fully dissociate (separate completely into ions)

The pH and the acidity are both important add the amount of acid you need for flavour and make sure you are at the right pH. If you are too low, yes you may need a base to raise the pH by adding a base.
Mark

 

[Adam_Langman]

Thanks Mark,

The comment re raising pH with acid was tongue in cheek. My confusion is why add base and acid.

If I can’t get both pH and acidity in the ideal spot, which is more important?

Best,

dam

 

[MHB]

Both answers come with a range value. Yeast will be happy anywhere in the 4-5pH window (and probably a fair way either side), worth understanding that that is an order of magnitude so it takes ten times as much "Acidity" to get a 1pH change.
If you put in the acid as listed (0.65%) 0.65g/L I would be very surprised if you were outside the 4-5pH window.
As to which is the most important, I can’t answer that, it comes down to taste and what else is in the recipe.
The amount of acidity and the pH both play a very important role in flavour. Too little acidity and your brew will be unstable and will taste flat and lifeless. Too low a pH (too much acidity) and it gets sharp and sour.

Follow your recipe, then take a couple of small samples, adjust the pH both up and down and see which you prefer.
Mark