pH Adjustment frequency / targets

[ColumbusAmongus]

Hello. I am doing my first mead (making it a melomel) and have a handy dandy pH meter to monitor the fermentation. I have a general question regarding pH. I noticed with mine any way that the pH dropped quite a bit in the primary and the fermentation seems to slow down. It dropped from 4.5 to 3 ish so I brought it back up to 4.5 with KOH and after that it seemed like the yeast kicked back in gear and finished up.

I only adjusted it once but I am curious what sort of pH ranges people try to maintain and how often to adjust. I want to add more fruit to the secondary so should I adjust again for a "final" pH target or is it fine to let it drift after the primary is done? Thanks!!!

 

[tweake]

i simply aim to keep it in the yeasts range. i've had one that was close to the yeasts limits but i'm told that being a melomel it has a lot more buffering so it wasn't a problem.

one reason degassing helps as removing co2 reduces the PH drop.

 

[biochemedic]

I've never really found (so far) any reason to actually measure the pH. I think if you avoid adding excessive acids to primary, the honey will buffer itself out. For this reason, I only add acid blend at bottling (when needed, to taste), and I generally avoid fermenting any excessively acidic fruits in primary; ie, I would rather ferment a lower volume of straight mead, then add the fruit.

Also, as tweake mentioned, CO2/carbonic acid is a big contributor to pH drop in primary, so degassing is quite important. I do try to plan brewing mead such that I will hopefully be around as much as possible for the first few days of fermentation, in order to facilitate SNA's and degassing -- I use the "fly by" technique...every time I go past the fermenter, I shake/swirl the $h!t out of it (you need to use a blow off tube rather than a standard airlock). I'd never brew a mead the day before leaving on vacation...

 

[ColumbusAmongus]

Yeah I have been shaking it daily and am quite shocked at how much gas evolves out each time. Would you say that shaking the CO2 out quite frequently helps maintain the pH better?

 

[fatbloke]

From a technical POV, early stage stirring/swirling, is for aeration. Yet an additional result of that, is to disturb the residual CO2 out of solution.

The CO2 is in the form of carbonic acid, until its removed somehow, and the movement of the liquid during aeration does just that.

Now don't forget, the CO2/carbonic acid isn't the only substance that causes pH swings. Gluconic acid forms and degrades, and I believe that other materials help to cause this as well.

Hence the removal of.the CO2/carbonic acid, is one way of helping reduce the pH swings some.

I usually keep an eye on pH readings, but I've never found it necessary to modify it during the ferment.....