National Homebrew Club Ireland

Brewing Discussions => All Grain Brewing => Topic started by: Paul86 on March 29, 2019, 04:49:27 PM

Title: Mash pH, how important is it??
Post by: Paul86 on March 29, 2019, 04:49:27 PM
Hi Everyone,

Im fairly new to Homebrew and have been trying to improve my beers.

I have been reading quite a bit on the topic of mash pH, essentially the optimum mash pH is between 5.2 and 5.5. At this pH the two main conversion enzymes can carry out there job at the most efficient rate giving you the best wort to brew your beer.

My question is what happens when the target is not reached??

Is it a case of incomplete enzymatic conversion and therefore poor efficiency?? If so can you just mash for longer until conversion is complete??

Are off flavours produced from a higher pH????

Are there are other potentially negative side effect produced from mashing at the wrong pH.

Can you still brew good beer using mash that wasnt carried out at Ph 5.2???
Title: Re: Mash pH, how important is it??
Post by: Tom on March 29, 2019, 06:37:25 PM
Off flavours aren't produced at an incorrect mash pH, but they'll develop down the line. Mash pH is about conversion, sparge pH (alkalinity levels) will extract astringent components, boil oh affects hop oil efficacy and coagulation, fermenter pH affects yeast performance, and finished product pH affects flavour. Start the mash right and it should all fall into place.

I dunno if I've ever said (I say it a lot) test your alkalinity for each brew, and bring it in line, for a flawless brewday.

"Can you still brew good beer using mash that wasnt carried out at Ph 5.2?"
I have literally no idea. I don't have a pH metre.
Title: Re: Mash pH, how important is it??
Post by: DEMPSEY on March 30, 2019, 04:24:35 AM
+1 to all said above. Mash PH is essential as well as a sparge PH. The rule of thumb is to not go above 5.9 PH  for end of running but it's best to be lower than this number. 
Title: Re: Mash pH, how important is it??
Post by: DEMPSEY on March 30, 2019, 04:31:00 AM
If you get a PH meter it is easy to be able to measure PH as the brew day progresses. I use 2 small egg cups so I can scoop small measures that can quickly be cooled for accurate reading. If you take measurements regularly at each stage of the Brew day you will be able to adjust your PH in time.
Title: Re: Mash pH, how important is it??
Post by: Paul86 on April 01, 2019, 08:12:13 AM
Quote from: Tom on March 29, 2019, 06:37:25 PM
Off flavours aren't produced at an incorrect mash pH, but they'll develop down the line. Mash pH is about conversion, sparge pH (alkalinity levels) will extract astringent components, boil oh affects hop oil efficacy and coagulation, fermenter pH affects yeast performance, and finished product pH affects flavour. Start the mash right and it should all fall into place.

I dunno if I've ever said (I say it a lot) test your alkalinity for each brew, and bring it in line, for a flawless brewday.

"Can you still brew good beer using mash that wasnt carried out at Ph 5.2?"
I have literally no idea. I don't have a pH metre.

If you dont measure pH how d you know that you are mashing at the correct ph? What do you use to alter the pH of an alakline mash???
Title: Re: Mash pH, how important is it??
Post by: Paul86 on April 01, 2019, 08:13:19 AM
Quote from: DEMPSEY on March 30, 2019, 04:31:00 AM
If you get a PH meter it is easy to be able to measure PH as the brew day progresses. I use 2 small egg cups so I can scoop small measures that can quickly be cooled for accurate reading. If you take measurements regularly at each stage of the Brew day you will be able to adjust your PH in time.

The Egg cups seem like a really good way of quickly measuring the pH will defiantly be doing this in future  ;)
Title: Re: Mash pH, how important is it??
Post by: Tom on April 01, 2019, 06:50:44 PM
I know what to expect from certain levels of Alkalinity and calcium chloride and sulphate additions. The mash looks good, converts in a reasonable amount of time, the yeast floats and then flocculates, and the finished beer has a great head and clarity. That's good enough for me. The pH is clearly within a reasonable range.

I acidify all my brewing liquor first, not to a specific pH, but to a certain Alkalinity. Then, provided that Palmer, Kaminsky, etc etc are correct, it should all go nicely from there.

Anything with only pale malts gets dropped to 10 to 20 ppm Alkalinity, then progressively more alkaline as I brew darker, up to 100ppm or so for a stout (if I mash the roast, which I do).

Hope that helps. My way and the pH meter way are, of course, complimentary, I just don't bother with the second part.

Sorry, and I use CRS for bitters, lactic acid for stouts.
Title: Re: Mash pH, how important is it??
Post by: Slev on April 02, 2019, 10:37:09 AM
I use to have a ph pen bought off amazon for about 10 euro. It was definitely one of the worse things ive purchased. It drove me mad. It was very inconsistent in its readings. So it made me question whether i was doing all my mineral/acid additions incorrectly.
In the end i stopped using it, and just stick with Brun Water calculations.
I dont know my ph, but i know if i follow brun water, I am going to be in the ball park.
(but i would like to confirm with an accurate ph meter so- is it something i should invest in?  Had thought of this one: https://m.aliexpress.com/item/32923057278.html?spm=a2g0n.shopcart-amp.item.32923057278& )
Title: Re: Mash pH, how important is it??
Post by: DEMPSEY on April 02, 2019, 12:03:29 PM
If you buy a PH meter make sure its a decent one or else the cheap one will drive you nutz ;D
Title: Re: Mash pH, how important is it??
Post by: Slev on April 02, 2019, 01:47:37 PM
Quote from: DEMPSEY on April 02, 2019, 12:03:29 PM
If you buy a PH meter make sure its a decent one or else the cheap one will drive you nutz ;D

You are right. The one above is one morebeer stock. They usually have reliable equipment (i think, but  could be completely wrong there!)

How often do you use your ph meter in practice? Is it a case, of using it for a few brews, and using it less and less?
Title: Re: Mash pH, how important is it??
Post by: DEMPSEY on April 03, 2019, 07:19:59 AM
When I brew I use it a lot through the brew day. I like to record the mash PH at the start and at the sparge. I record the wort before the boil and at the end too. And then when the wort goes to the fermenter I do again. It easy to do this for me as my 2 little egg cups just get a scoop and let's me get on while it cools and reads the numbers.
Title: Re: Mash pH, how important is it??
Post by: Tom on April 03, 2019, 08:31:03 AM
One thing that always puzzled me, Dempsey, is when do you consider the mash pH to have stabilised? Obviously the reactions don't happen instantly. How long does it take in a typical, working well mash?
Title: Re: Mash pH, how important is it??
Post by: Oh Crap on April 03, 2019, 09:25:08 AM
Quote from: Tom on April 03, 2019, 08:31:03 AM
One thing that always puzzled me, Dempsey, is when do you consider the mash pH to have stabilised? Obviously the reactions don't happen instantly. How long does it take in a typical, working well mash?
In work we have found that 20mins into mash when the pH has stabilized..we have measured at 5 minutes intervals for the full mash and over time have found that it is stable at 20. In saying that we do a constant recirculation from 5mins...
Title: Re: Mash pH, how important is it??
Post by: DEMPSEY on April 03, 2019, 11:17:42 AM
Same here. 15 minutes is my mark.
Title: Re: Mash pH, how important is it??
Post by: Oh Crap on April 03, 2019, 02:34:36 PM
Quote from: DEMPSEY on April 03, 2019, 11:17:42 AM
Same here. 15 minutes is my mark.
Between us that's conclusive proof so  ;D
Title: Re: Mash pH, how important is it??
Post by: Paul86 on April 04, 2019, 08:31:53 AM
Quote from: Tom on April 01, 2019, 06:50:44 PM
I know what to expect from certain levels of Alkalinity and calcium chloride and sulphate additions. The mash looks good, converts in a reasonable amount of time, the yeast floats and then flocculates, and the finished beer has a great head and clarity. That's good enough for me. The pH is clearly within a reasonable range.

I acidify all my brewing liquor first, not to a specific pH, but to a certain Alkalinity. Then, provided that Palmer, Kaminsky, etc etc are correct, it should all go nicely from there.

Anything with only pale malts gets dropped to 10 to 20 ppm Alkalinity, then progressively more alkaline as I brew darker, up to 100ppm or so for a stout (if I mash the roast, which I do).

Hope that helps. My way and the pH meter way are, of course, complimentary, I just don't bother with the second part.

Sorry, and I use CRS for bitters, lactic acid for stouts.

Thanks for the Info Tom I recently bought a vial of Lactic Acid for a choc oatmeal stout I plan to brew. Fingers crossed this one turns a bit better than my more recent attempts.
Title: Re: Mash pH, how important is it??
Post by: Tom on April 05, 2019, 04:57:53 PM
There's not much info on the accurate dosing of Lactic acid, so I spent a couple of hours and many, many cups of tea, figuring out the following, and I've checked the sums, and I've road tested it. I'm happy enough to share this with y'all:

Alkalinity reduction using 80% Lactic Acid (HBC strength)

Alkalinity to be reduced (ppm) x volume (litres) = ________
Multiply the answer by 0.00186, answer in mls.

For example, I have 370ppm alkalinity (which I bloody do, damnit) and I want 100ppm. So I need to reduce 270ppm. I will be treating 30 litres of water.
270 x 30 = 8,100 mg of alkalinity.
8,100 x 0.00186 = 15ml Lactic Acid.

:)

Dose the brewing liquor at the start, if you can, as it's easier. The alkalinity reduction will mostly take place in the mash tun, the same as phosphoric acid. Sulphuric and Hydrochloric reduction will take place in the HLT.
Title: Re: Mash pH, how important is it??
Post by: imark on April 08, 2019, 12:20:21 AM
There's no point having a pH meter unless you calibrate it with buffer solutions regularly. If you aren't doing this then your readings aren't reliable.
In my experience you need to do this each week or brewday. Whichever is first.
Title: Re: Mash pH, how important is it??
Post by: Paul86 on April 09, 2019, 03:57:33 PM
Quote from: Tom on April 05, 2019, 04:57:53 PM
There's not much info on the accurate dosing of Lactic acid, so I spent a couple of hours and many, many cups of tea, figuring out the following, and I've checked the sums, and I've road tested it. I'm happy enough to share this with y'all:

Alkalinity reduction using 80% Lactic Acid (HBC strength)

Alkalinity to be reduced (ppm) x volume (litres) = ________
Multiply the answer by 0.00186, answer in mls.

For example, I have 370ppm alkalinity (which I bloody do, damnit) and I want 100ppm. So I need to reduce 270ppm. I will be treating 30 litres of water.
270 x 30 = 8,100 mg of alkalinity.
8,100 x 0.00186 = 15ml Lactic Acid.

:)

Dose the brewing liquor at the start, if you can, as it's easier. The alkalinity reduction will mostly take place in the mash tun, the same as phosphoric acid. Sulphuric and Hydrochloric reduction will take place in the HLT.

Hi Tom,

Great bit of work there and thanks for sharing, just wondering where you got 0.00186 from?? is this related to the concentration of the Lactic acid of is it a co-efficient you calculated??

Also Im not sure of the alkalinity of my water, can this be calculated from the bicarb or ph??
Title: Re: Mash pH, how important is it??
Post by: DEMPSEY on April 09, 2019, 05:31:09 PM
A TDS meter, total dissolved salts are cheap to buy and a salifert Caco3 fish tank test kit as well will give you what you need.
Title: Re: Mash pH, how important is it??
Post by: DEMPSEY on April 09, 2019, 05:31:58 PM
Total dissolved solids ;)
Title: Re: Mash pH, how important is it??
Post by: Tom on April 09, 2019, 08:01:24 PM
Cheers Paul86, that is a really good question.

I don't remember exactly how I came by it, it's written in an Aisling copybook that has been misplaced. Something to do with MMols, chemical equations and atomic weights (belive it or not). There really was nothing online about using Lactic acid accurately in beer, just 'don't use more than xxx in 5 gallons'. I'll have a hunt for the book and show my workings when I find it. And I figured it out to the HBCs 80% lactic acid. If you get the 86% stuff, adjust accordingly.

Whilst looking for the above, though, I did rediscover my workings for how much Sodium, Potassium and Sulphates are contribuited to your beer when you use a campden tablet in your HLT. :D

And for my alkalinity I use the Salifert CaCO3 solution, but fish people call it KH. £9 off ebay.