When to test the mash PH

[David Koepke]

First post!! I am new to BIAB. At what point should I test the mash ph? How much lactic acid for a 5 gallon batch? Per my city water report, my water is 8.33 ph. I suspect this to be an issue when I get to mash. Thanks!

David

 

[Blazinlow86]

Generally about 15 mins into the mash at room temp. But your gonna get alot of differing opinions on this topic. How much acid to add will be determined by your specific water source/salt additions and grain bill. If it's your first batch I wouldn't be super over concerned about it tbh. Cheers

 

[Gnomebrewer]

Most test at 15 to 20 minutes in to the mash, but there are advocates for testing later (30 to 60 minutes).

The pH of your water is fairly irrelevant - the alkalinity or bicarbonate is what you need to know.

 

[HTH1975]

15 mins is pretty standard. I don’t see the point in doing this after 30 or 60 mins as conversion will have mostly been completed by that point. IF your mash pH is too high after 30-60 mins, you’ve lost your opportunity to correct the pH.

 

[Silver_Is_Money]

15 mins is pretty standard. I don’t see the point in doing this after 30 or 60 mins as conversion will have mostly been completed by that point. IF your mash pH is too high after 30-60 mins, you’ve lost your opportunity to correct the pH.

There is no actual opportunity to adjust mash pH conditions on the fly to begin with, as the starch to sugars conversion is mostly if not completely over already by the time you draw, cool, and properly (which is far different from hastily) pH test a 10-15 minute drawn sample. So why take an early sample that is not going to be truly representative of mash pH, since at 15 minutes the mash water has not yet fully permeated the deepest confines of the grist and the entire process of neutralizing the pH of the grist to that of the desired pH target is still actively evolving? Wait until at least 30 minutes, though I prefer 60 minutes. Or take samples at 30 minutes and 60 minutes for education purposes. Most conversions are completed by the 30 minute mark, but some linger a bit to more like 60 minutes. Particularly they will linger if diastatic enzyme concentration is on the lower end.

 

[Silver_Is_Money]

Mash pH tends to rise as time and conversion progresses, and until stability is reached at the end of the mash. Early samples will inevitably yield false low mash pH readings. If you adjust pH upward based upon a false low indication of mash pH, you may well end up with a higher than desired pH leading into the boil. And that is generally not a good thing. And since you sampled too early in the process you most likely won't ever even know about it.

Add and mix all of your requisite calculated mineralization and acids/bases to the mash water before doughing it into the grist.

 

[Blazinlow86]

Generally about 15 mins into the mash at room temp. But your gonna get alot of differing opinions on this topic. How much acid to add will be determined by your specific water source/salt additions and grain bill. If it's your first batch I wouldn't be super over concerned about it tbh. Cheers

See what I mean. Your getting every answer from 15 mins to 60mins. Just get one of the free calculators and use what it suggest for your first time measure and then adjust as you see fit from there. To clarify I'm not saying anyone's replays are incorrect just this is a highly debated topic and lots of opinions. Cheers

 

[RPh_Guy]

22 minutes is correct and everything else is wrong.

 

[Silver_Is_Money]

Some might say that the answer to everything is 42, and as such 42 minutes is best.

 

[mabrungard]

Mashing pH can vary during the mashing period. But clearly, 42 minutes is best.

 

[bracconiere]

uhh, i've always just stuck my probe in the much tun after dough in.... as far as i know you want 5.5 or something at room temp, and 5.2 at mash temp....but i get the best results with 5.3....

 

[KonservativeJay]

Some might say that the answer to everything is 42, and as such 42 minutes is best.

A very prudent answer

 

[bdogg171]

Mashing pH can vary during the mashing period. But clearly, 42 minutes is best.

Whatever Bru’n Water says it should be is good enough.
I used to check every batch and the info always matched or was close enuff, I don’t even check anymore.

 

[mabrungard]

Well, what is written in Bru'n Water will be updated based on the mashing trials I've been conducting. I've seen this response for years in my mashes where the pH rises through the mashing period. As Larry said above and I've now confirmed without any doubt to me, pH does rise during the mash. Thirty minutes is definitely the earliest you should consider the mash pH to be somewhat valid. Forty five minutes is even more accurate. The pH becomes relatively constant after that time.

Measuring at 15 minutes AND planning on implementing any sort of pH adjustment is not a good approach. The pH SHOULD be significantly lower than your targeted pH at the 15 minute mark. You shouldn't be adding a base to your wort if you find that the mash pH is several tenths lower than you intend. The ONLY reason that I would consider an adjustment is if I measured a pH that is way over my target. If you're using a competent brewing water calculator, your mash pH should be a bit low at the 15 min mark and it will climb during the mash.

You can measure at 15 min, but it only matters at 30 and 45 minutes. The pH of the early mashing stage is less important. Making sure that your wort pH into the kettle is in the 5.2 to 5.6 range is what is more important.

 

[Blazinlow86]

Well, what is written in Bru'n Water will be updated based on the mashing trials I've been conducting. I've seen this response for years in my mashes where the pH rises through the mashing period. As Larry said above and I've now confirmed without any doubt to me, pH does rise during the mash. Thirty minutes is definitely the earliest you should consider the mash pH to be somewhat valid. Forty five minutes is even more accurate. The pH becomes relatively constant after that time.

Measuring at 15 minutes AND planning on implementing any sort of pH adjustment is not a good approach. The pH SHOULD be significantly lower than your targeted pH at the 15 minute mark. You shouldn't be adding a base to your wort if you find that the mash pH is several tenths lower than you intend. The ONLY reason that I would consider an adjustment is if I measured a pH that is way over my target. If you're using a competent brewing water calculator, your mash pH should be a bit low at the 15 min mark and it will climb during the mash.

You can measure at 15 min, but it only matters at 30 and 45 minutes. The pH of the early mashing stage is less important. Making sure that your wort pH into the kettle is in the 5.2 to 5.6 range is what is more important.

Well said and agreed 100%

 

[Silver_Is_Money]

What? You would agree to sampling at 45 minutes as opposed to the perfect 42 minutes? Blasphemy!!!

 

[RM-MN]

Well, what is written in Bru'n Water will be updated based on the mashing trials I've been conducting. I've seen this response for years in my mashes where the pH rises through the mashing period. As Larry said above and I've now confirmed without any doubt to me, pH does rise during the mash. Thirty minutes is definitely the earliest you should consider the mash pH to be somewhat valid. Forty five minutes is even more accurate. The pH becomes relatively constant after that time.

Measuring at 15 minutes AND planning on implementing any sort of pH adjustment is not a good approach. The pH SHOULD be significantly lower than your targeted pH at the 15 minute mark. You shouldn't be adding a base to your wort if you find that the mash pH is several tenths lower than you intend. The ONLY reason that I would consider an adjustment is if I measured a pH that is way over my target. If you're using a competent brewing water calculator, your mash pH should be a bit low at the 15 min mark and it will climb during the mash.

You can measure at 15 min, but it only matters at 30 and 45 minutes. The pH of the early mashing stage is less important. Making sure that your wort pH into the kettle is in the 5.2 to 5.6 range is what is more important.

With my fine milling of the grain the mash conversion is over before the 15 minutes so testing and adjusting the pH at the point is a waste of time. Mash pH matters when conversion is going on, not after it is complete. By 30 minutes I have removed the grains from the wort and have already started heating toward boil so the 45 minute reading is ??? Take your pH reading at 15 minutes but don't bother adjusting it. Plan your next brew and do the adjustment before you add the grains. Take the pH reading at 15 minutes again and make plans for the next brew. Remember that you are targeting a range of pH and don't get hung up on hitting an exact number.

 

[Oginme]

Well, what is written in Bru'n Water will be updated based on the mashing trials I've been conducting. I've seen this response for years in my mashes where the pH rises through the mashing period. As Larry said above and I've now confirmed without any doubt to me, pH does rise during the mash. Thirty minutes is definitely the earliest you should consider the mash pH to be somewhat valid. Forty five minutes is even more accurate. The pH becomes relatively constant after that time.

Measuring at 15 minutes AND planning on implementing any sort of pH adjustment is not a good approach. The pH SHOULD be significantly lower than your targeted pH at the 15 minute mark. You shouldn't be adding a base to your wort if you find that the mash pH is several tenths lower than you intend. The ONLY reason that I would consider an adjustment is if I measured a pH that is way over my target. If you're using a competent brewing water calculator, your mash pH should be a bit low at the 15 min mark and it will climb during the mash.

You can measure at 15 min, but it only matters at 30 and 45 minutes. The pH of the early mashing stage is less important. Making sure that your wort pH into the kettle is in the 5.2 to 5.6 range is what is more important.

I have stopped doing a 15 minute pH check and now only check the pH at the end of the mash. If I end up at target (usually around 5.4, but it depends upon style), I know that I was most likely at 5.1 to 5.2 at the early stages, 5.3 to 5.4 about midway through the mash in order for it to settle in at around 5.4 at the end of the mash. Over the course of 30 to 40 brews where I monitored my mash pH, it has never failed to follow this pattern. The main reason for checking at the end of the mash now it to maintain the offset in the pH calculators to my ending pH. Using Bru'n water or BeerSmith, I see a distinct offset from predicted pH to actual measured pH which is consistent regardless of which tool I use.

 

[littlewashingtonbrewery]

Question for Martin B. You said "The pH SHOULD be significantly lower than your targeted pH at the 15 minute mark."
How much does it typically increase. Lately I have been hitting BruNWater numbers but I have been checking at 15 minutes. So I guess I am wondering how much I am off at the end of my usual 45 minute mash. Editing my post - I just reread the excellent post by Oginme directly above mine and curious if your results are consistent with his. Is there any variables I should be looking at to explain my pH readings difference or if I should start using an offset. Thanks all for the excellent discussion!

 

[mabrungard]

While it is generally true that starch conversion is complete at the 15 minute mark in a mash, there is still a LOT of sugar breakdown that should be performed with additional mashing time. I wouldn't even think of ending mashing at 15 or 30 minutes. I find that I end up with high unfermentability and worty beers when I tried that short mash approach.

From the data that I've collected to date, the amount of pH rise observed in the trials was typically in the 0.2 to 0.4 range and the thinner the mash, the larger the rise. But in all cases (except where baking soda was used), the final pH for all the worts (regardless of thickness) were fairly close together.

 

[Blazinlow86]

While it is generally true that starch conversion is complete at the 15 minute mark in a mash, there is still a LOT of sugar breakdown that should be performed with additional mashing time. I wouldn't even think of ending mashing at 15 or 30 minutes. I find that I end up with high unfermentability and worty beers when I tried that short mash approach.

From the data that I've collected to date, the amount of pH rise observed in the trials was typically in the 0.2 to 0.4 range and the thinner the mash, the larger the rise. But in all cases (except where baking soda was used), the final pH for all the worts (regardless of thickness) were fairly close together.

I've found similar results with 0.2 to 0.4 rise through a 60 min mash. Cheers

 

[RM-MN]

While it is generally true that starch conversion is complete at the 15 minute mark in a mash, there is still a LOT of sugar breakdown that should be performed with additional mashing time. I wouldn't even think of ending mashing at 15 or 30 minutes. I find that I end up with high unfermentability and worty beers when I tried that short mash approach.

From the data that I've collected to date, the amount of pH rise observed in the trials was typically in the 0.2 to 0.4 range and the thinner the mash, the larger the rise. But in all cases (except where baking soda was used), the final pH for all the worts (regardless of thickness) were fairly close together.

Surprisingly I didn't get much difference in fermentability with a 10 minute mash compared to the same grain bill with a 30 minute mash. The difference I noticed was in flavor which is why I do not suggest to people that they go shorter than 30 minutes.

 

[Nathan Hassey]

I'm confused. If it rises throughout the mash then what if it is already way to high at the beginning? Wouldn't you want to make sure you are at least on the low end so that as it rises it stays within the range throughout the mash time?

 

[VirginiaHops1]

I'm confused. If it rises throughout the mash then what if it is already way to high at the beginning? Wouldn't you want to make sure you are at least on the low end so that as it rises it stays within the range throughout the mash time?

They're saying don't try to adjust your mash ph UP if you're below target early on, because it will rise during mash. The only adjustment you should be doing is adjusting down if you're too high. I've never tried to adjust during the mash though. Early batches when I was trying to figure things out my mash ph hit 5.9 a few times I just let it ride and adjusted on subsequent batches. Those beers turned out fine, actually one of them was one of my better brews to date.

 

[Nathan Hassey]

Ahh ok. Thanks for clarifying. So it still should be checked early on then to ensure its not too high correct? I use distilled water with salts which is why im asking this.

 

[sarandos25]

@mabrungard could you please point me to reference materials on pH behavior during the mash? I'm experiencing the opposite of what you had posted here a few years back. I just brewed an IPA yesterday, the pH readings were

10' 5.43 (I know this is too early per conventional wisdom)
20' 5.36
30' 5.38
45' 5.14
60' 4.78

This is now a recurring event, where my mash has dipped below 5 towards the 45/60 minute mark. Generally all acid and salt additions have been done prior to the mash, but because I kept getting such low pH readings, yesterday I withheld all salts and acid, so the mash pH observed was just the result of the grains / water (i.e. there was no water treatment performed).

Grain Bill was 7.2 kg pale, 1.2kg pale wheat, 1.2kg oats, .2 kg carared.

I appreciate any advice on the following 2 questions:
1. A declining pH during the mash, is it normal? If not, what could be at play?
2. Using this particular example, would you have interfered at any point? I was shooting for a 5.3 pH

 

[mabrungard]

That is odd behavior. Is that wort recirculated through the mash? If its not, there is no way for the mash to be truly 'mixed'. Are the water amendments added to the water and thoroughly mixed prior to the grain being added?

 

[sarandos25]

That is odd behavior. Is that wort recirculated through the mash? If its not, there is no way for the mash to be truly 'mixed'. Are the water amendments added to the water and thoroughly mixed prior to the grain being added?

Is that wort recirculated through the mash? <- No, most of the time I don't. I keep the HLT at sparge strike temp which would cause the mash temp to rise given my setup. Per your feedback, I will keep the HLT at a lower temp and recirculate. Do you have any guidance on recirculation? Throughout the entire mash, for portions, thanks.

Are the water amendments added to the water and thoroughly mixed prior to the grain being added? <- Usually yes. This last brew I didn't make any water adjustments because the pH tends to always drift below 5 so I figured the salts and lactic acid would only make things worst. I'll brew again and determine if the recirculation during the mash makes my pH more stable or at least more normal in that it will rise instead of decline.

 

[AlcheMania]

First post!! I am new to BIAB. At what point should I test the mash ph? How much lactic acid for a 5 gallon batch? Per my city water report, my water is 8.33 ph. I suspect this to be an issue when I get to mash. Thanks!

David

Use a calculator and pretreat your water. Dilute if necessary. Buy a microscale and weigh your salts ahead of your brew day. Water chem took my beer quality and consistency to the next level. I check at 10, 20, and 30 minutes and add lactic acid as needed.

 

[Silver_Is_Money]

Indeed going from 5.43 pH to 4.78 pH across the mash is odd behavior!

10^−4.78 ÷ 10^−5.43 = 4.467

Where is the extra 446.7% more H+ ion (I.E., more acid) coming from? Even most dark caramel and/or deep roasted malts don't mash at much lower than 4.78 pH when they are standing alone.