Adjusting pH on the fly?

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matt76

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Bear with me while I nerd out a bit with some technical questions - I know this stuff isn't everyone's cup of tea... :laugh8:

I've recently started to take a closer interest in pH - this was actually sparked off by my first attempt at making cider, which has turned out really sour, literally like sucking on a lemon - I measured the pH at 3.1.

I used several gradual additions of bicarbonate of soda to raise the pH up to around 3.6 - still very sour but a noticeable difference and much more palatable for only a small change in pH (and yes, I do realise pH is a logarithmic scale).

So as a result I'm now paying closer attention to pH of my beer from grain to glass - if I'm taking hydrometer samples anyway I may as well check the pH too.

One area where I struggle with water treatment and pH is my mega hard tap water - I know I could use Tesco Ashbeck but I'd prefer to avoid this to reduce plastic waste.

I use Brewer's Friend as a water calculator and generally add lactic acid (malty beers) or CRS (hoppy beers) to get the acidity at least roughly in the right area. Lactic acid is a challenge - it's powerful stuff alright but you don't want to exceed about 0.3ml/L as beyond this it can impact on flavour. CRS is less potent and doesn't surely impact taste but it impacts the level of chloride and sulphate.

Now here's the thing, with paler beers my mash pH measured at 25degC is generally high - if I'm targeting say 5.2 for something like a Pilsner or Helles it'll generally be somewhere like 5.4, maybe 5.6 or even 5.8.

So what are my options? What kind of things can I do to get pH back on track?

I could just live with it - the beer tastes fine. But I'm interested to see what incremental gains I can make, and also I do wonder whether pH in the finished beer is a factor with chill haze (a persistent thorn in my side).

In particular I'm thinking can I simply add more acid in the mash if my measured pH is still off? I don't think a little extra gypsum or CaCl is gonna have enough effect here, so is need more acid.

So if I did this I'm thinking I'd have to look at phosphoric acid as I'm pretty much on the 0.3ml/L limit with lactic acid (typically I already add 5ml lactic acid 80% to a total of 15L water, plus other additions).

Presumably only very small amounts of additional acid would be needed to effect a -0.2 to -0.4 change in pH?

The other issue here is timing - usually by the time I've cooled my sample to 25degC and checked the pH I've already started heating the wort for the boil. So if further pH adjustment is needed can I just chuck it in the boil?

One more thought - does anyone ever adjust pH (up or down) even later in the process? Close to packaging say? Just curious given the effect it can have...

If anyone has experience with this stuff I'd appreciate your guidance.

Cheers,

Matt athumb..
 

strange-steve

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So what are my options? What kind of things can I do to get pH back on track?
First of all, if the pH is between 5.2 and 5.8 then I wouldn't be too bothered about trying to adjust it on the fly. If your pH is always on the high side then could you simply set your target a little lower? Fwiw I tend to target 5.4 rather than 5.2.
Presumably only very small amounts of additional acid would be needed to effect a -0.2 to -0.4 change in pH?
Possibly, but then a mash has a high buffering capacity, plus I don't know if it's possible to predict exactly how much acid you'd need and so you'd have to take a guess at it, and by the time you'd taken another sample, cooled it, measured it, the mash would probably be done. Mid-mash adjustment probably isn't very practical.
So if further pH adjustment is needed can I just chuck it in the boil?
Probably not worth doing unless your mash pH was way off.
One more thought - does anyone ever adjust pH (up or down) even later in the process? Close to packaging say? Just curious given the effect it can have...
Some check post-fermentation pH (I seem to remember Gordon Strong recommending this) and if necessary adjust it to below 4.4 which helps with stability and shelf life. If you have a good healthy fermentation though this is probably not needed.
 

Drunkula

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I've forgotten to adjust the mash a few times so threw the salts in the boil and some acid. The difference the acid makes for forming hot break and clear wort is has been crazy for me..
 

matt76

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Thanks @strange-steve , very insightful and very pragmatic advice athumb..

Perhaps the answer then (apart from don't worry about it if it's roughly on the right range! :laugh8: ) is to go a touch more heavy handed with the acid...

So if a calculator is telling me add 20ml CRS maybe I need 2.5-5ml more than that (harder with lactic acid though due to the taste thing). Also I'd guess with the way the pH scale works (log rather then linear), presumably you'd need to add disproportionally more acid to drop the pH more and more.
 

Galena

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If you are missing your target pH every time, do you have the malt colour dialed in correctly?
 

strange-steve

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Perhaps the answer then (apart from don't worry about it if it's roughly on the right range! :laugh8: ) is to go a touch more heavy handed with the acid...
Yeah that's what I'd do.
Also I'd guess with the way the pH scale works (log rather then linear), presumably you'd need to add disproportionally
Alkalinity and buffering from the mash complicates it a little but essentially yes thumb.
 

matt76

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If you are missing your target pH every time, do you have the malt colour dialed in correctly?
Yes - the BF water calculator is linked directly to the recipe and it takes the precise grain type, colour and quantity from there.

But it's a good suggestion - I have noted in the past that different calculators predict a range of different mash pH's, so potentially something else to try athumb..
 

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