Does acid go off?

[matt76]

Just lately (last 3 brews) I suddenly seem to be measuring quite a high mash pH, i.e. pH > 6.0, whereas even with my dodgy hard water I'd expect to measure maybe 5.5-5.8ish

So before I write a very long post speculating and asking why this might be, can anyone tell me, does acid go "off"?

Specifically, I use either lactic acid (malty beers) or CRS (hoppy beers) - but I've had both bottles about 12 months so I wonder if the acid could oxidise for example, to the extent that it becomes less effective over time?

Anyone know?

Cheers,

Matt

 

[Drunkula]

I'm using a bottle of lactic acid that's dated 2006 from stuff I got in a car boot sale. It's definitely acidic, confirmed by tasting, my pH meter, and the amazing difference in break material in the boil.

 

[matt76]

Thanks @Drunkula

It did occur to to check the pH - I've got new bottles of lactic acid and CRS ready to be used. If I'm lucky there might just be enough seems left in the old bottles to check the pH.

From what you say it seems like I shouldn't expect a major difference but at least I can rule out that explanation.

 

[foxbat]

I think it's more likely that your pH meter has gone off. I've heard the cheap ones are rubbish and they all need the probes to be stored in a special solution. I just make my additions while reciting an incantation to the Brunwater spreadsheet and call it a good 'un.

 

[The-Engineer-That-Brews]

I don't think there is much chance of acid going off.
As @foxbat says, it may be more likely to be a problem with your meter.
Personally I like the Johnsons narrow range pH strips (pH 4.6-6.2) - at £5.50 for 50 strips they are quick, easy and economical :-)

 

[matt76]

Thanks for the tips

I checked earlier the CRS I brewed with yesterday - pH meter straight down to pH = 0.5 so I'm pretty certain the acid hasn't gone off!

And yes it has occurred to me my meter could be the issue. I have some powder to recalibrate but no distilled water at present to make up the solutions

However, the curious thing is when I measure pH of various things - tap water, fermented beer before dry hop, beer after dry hop etc. then the measured pH and changes in pH seem about right. So if it is out,I don't think it's our by much.

Mind you, since pH is a log scale then who knows!

 

[matt76]

I don't think there is much chance of acid going off.
As @foxbat says, it may be more likely to be a problem with your meter.
Personally I like the Johnsons narrow range pH strips (pH 4.6-6.2) - at £5.50 for 50 strips they are quick, easy and economical :-)

View attachment 36015

Thanks for the tip

I do have some pH strips actually - not narrow range unfortunately but might have been useful to at least try and cross check.

 

[matt76]

I don't think there is much chance of acid going off.
As @foxbat says, it may be more likely to be a problem with your meter.
Personally I like the Johnsons narrow range pH strips (pH 4.6-6.2) - at £5.50 for 50 strips they are quick, easy and economical :-)

View attachment 36015

Quick update on this - good tip from @The-Engineer-That-Brews , thanks

I got some of these strips and have used them a few times - straightforward and simple

Only issue is pH 4.6 isn't low enough for the kettle sour I've got on the go at the moment - should have also got a pack of the Wine/Cider ones for lower pH. Next time...