Mash PH what am I doing wrong

[overseasbrewer]

OK here is the deal. I have been brewing for a couple of years now without bothering to check my mash PH. Now I wanted to make a change to that so I thought I was going to give it a try. I got myself a nice PH meter from Amazon and gave it a try. 10 minutes after I started the mash I pulled a sample, chilled it and got a 5.8 reading. I added about 2.5 ml of lactic acid to the mash, stirred it in and waited a few minutes to take a new sample. This again read 5.8. I added an additional 4 ml waited another few minutes and then got a reading of 5.7. At this point, I was afraid to add any more lactic acid and just went on with the brew as regular. What did I do wrong?

 

[schmurf]

Did you give it a good stir prior to taking the samples?

 

[overseasbrewer]

Did you give it a good stir prior to taking the samples?

Yes

 

[schmurf]

You've done all the calibration needed, cleaned the head after every use etc?

 

[ScrewyBrewer]

Taking 15 to 20 minutes for your brewing water or your mash pH to stabilize between acid/base additions I'm not surprised by your readings. The problem with trying to adjust pH during the mash is that by the time the wort stabilizes its too late for you to get a good reading. Or for that matter too late to make a difference.

 

[overseasbrewer]

Taking 15 to 20 minutes for your brewing water or your mash pH to stabilize between acid/base additions I'm not surprised by your readings. The problem with trying to adjust pH during the mash is that by the time the wort stabilizes its too late for you to get a good reading. Or for that matter too late to make a difference.

So you're saying I should adjust my water before mashing in?

 

[mabrungard]

Stirring does not really work. You would have to an incredible amount of stirring to obtain a homogeous mixture. Recirculation is a better way to homogenize the wort composition.

I'm assuming you performed no other water adjustments prior to adding the grain? Water adjustments are best made to the water prior to adding the grain since you can assure that the constituents are fully dissolved and dispersed throughout the water volume. Of course, you need to have some idea of where you need to take those adjustments before hand and that's where a brewing water calculator comes in.

You didn't mention the batch size, but its possible that the 2.5 and 4 ml additions were minor in relation to the actual need. But there should have been some downtick in the pH anyhow.

 

[ScrewyBrewer]

So you're saying I should adjust my water before mashing in?

Yes absolutely.

 

[overseasbrewer]

Awesome this was really helpful y'all. One more question. Could this total of 6.5ml of lactic acid have any effect on the flavor of my 5.25 gallon batch of Belgium raspberry wit?

 

[mabrungard]

Awesome this was really helpful y'all. One more question. Could this total of 6.5ml of lactic acid have any effect on the flavor of my 5.25 gallon batch of Belgium raspberry wit?

Probably not. That's probably less than 1 ml per gallon of brewing water and that is generally not perceptible as lactate.

 

[overseasbrewer]

Thanks

 

[ajdelange]

OK here is the deal. I have been brewing for a couple of years now without bothering to check my mash PH. Now I wanted to make a change to that so I thought I was going to give it a try. I got myself a nice PH meter from Amazon and gave it a try. 10 minutes after I started the mash I pulled a sample, chilled it and got a 5.8 reading. I added about 2.5 ml of lactic acid to the mash, stirred it in and waited a few minutes to take a new sample. This again read 5.8. I added an additional 4 ml waited another few minutes and then got a reading of 5.7. At this point, I was afraid to add any more lactic acid and just went on with the brew as regular. What did I do wrong?

I'm afraid the answer was probably buying the "nice" pH meter from Amazon but post and let us know which one it was. I'm sure you can probably find some good ones on Amazon but most of what they sell are cheap Chinese knock-offs that often give disappointing results. The fact that you report 5.7 and 5.8 as pH values suggests that you have one of these (with one of the HBT vetted meters you would be reporting number with two digits to the right of the decimal point).

So you're saying I should adjust my water before mashing in?

It is better to make additions to the water rather than the mash as when you do it that way the added stuff is already dissolved and ready to go to work when it hits the mash.

Stirring does not really work. You would have to an incredible amount of stirring to obtain a homogeous mixture. Recirculation is a better way to homogenize the wort composition.

I would advise every brewer to do at least one decoction mash. The boiling darkens the decoction and when you return it and mix it in you will see very easily how much stirring it takes to get a homogenous mixture. It's not that much but the situation is exacerbated when only a few mL of someting are being added to gallons of mash. If you add to the mash in the future pull out a quart or so of thin mash, add the acid to that, stir it well, and then stir the acidified quart into the mash.

You didn't mention the batch size, but its possible that the 2.5 and 4 ml additions were minor in relation to the actual need. But there should have been some downtick in the pH anyhow.

There should but in the case of 2.5 mL addition it might not be visible. Assuming he is making 5 gallons, as the vast majority seem to do and mashing with 3.5 RO water using 90% Munton's Maris Otter with it's high (5.84) DI mash pH with 10% 20 L crystal at thickness 1.3 qts/lb he might expect a mash pH of 5.76. On his 1 decimal place meter that might well read 5.8. Adding 2.5 mL 88% lactic acid to this would lower the expected pH to 5.64, just a wee bit over 0.1 unit which the meter might not detect. But adding 6.5 mL should bring about a pH shift of -0.29 units which should be plainly detectable by even a 0.1 resolution meter. Of course perhaps he is doing a 50 gal batch but if it is indeed 5 gal then he can interpret this as, again, pointing to the pH meter.