Really low sparge ph

[THops]

Looking forward to your finding man.

Thanks to you and all who commented. My working theory is that that calculator is correct, and my sparge water really is 3.7 after the lactic addition. BUT since the runoff is only 3 gallons or so, it just doesn't matter. Maybe if I were running off 10 gallons it would...

 

[Yooper]

No measurements. You know how on the water calculator where it shows your mash pH? It also shows sparge pH. My sparge pH is often predicted really low. It seems odd.

Can you send me a link to that calculator page, or a screenshot? I need to look into it.

 

[THops]

Can you send me a link to that calculator page, or a screenshot? I need to look into it.

https://www.brewersfriend.com/mash-chemistry-and-brewing-water-calculator/

So, reporting back. For my Dubbel, I set the above water calculator to 5.3 mash pH. It calculated a sparge pH of 3.7.

I just took all the actual measurements.

The actual sparge (and strike) liquor pH before adding to the grain was measured at 4.4. So kinda close?

The actual sparged wort pH was 5.45 when I took a sample.

The actual mash pH was 5.38. Could be a refractometer calibration error, but reasonably close.

Not sure why it measured lower (perhaps sample stratification?), but the combined wort pre-boil pH was 5.3.

I do think I will set the pH closer to 5.2 next time, but overall I am pleased with these numbers. I have never taken all these pH readings, but I will from now on. Getting the pre-boil pH between 5.2 and 5.4 is the sweet spot, I understand, for the best hop utilization and smoother bitterness.

As for the calculator predicting the low sparge pH, I think it's just a bug/error? Or maybe it should be changed to say sparge liquor pH.

One thing of concern is what happens when it predicts a higher sparge pH, such as 5.5? Will that push the measured sparge pH above 6? For my process, I think the wise move is to see if I can get the the calculator below 4 for the sparge, assuming the predicted mash pH is in line.

 

[Yooper]

https://www.brewersfriend.com/mash-chemistry-and-brewing-water-calculator/

So, reporting back. For my Dubbel, I set the above water calculator to 5.3 mash pH. It calculated a sparge pH of 3.7.

I just took all the actual measurements.

The actual sparge (and strike) liquor pH before adding to the grain was measured at 4.4. So kinda close?

The actual sparged wort pH was 5.45 when I took a sample.

The actual mash pH was 5.38. Could be a refractometer calibration error, but reasonably close.

Not sure why it measured lower (perhaps sample stratification?), but the combined wort pre-boil pH was 5.3.

I do think I will set the pH closer to 5.2 next time, but overall I am pleased with these numbers. I have never taken all these pH readings, but I will from now on. Getting the pre-boil pH between 5.2 and 5.4 is the sweet spot, I understand, for the best hop utilization and smoother bitterness.

As for the calculator predicting the low sparge pH, I think it's just a bug/error? Or maybe it should be changed to say sparge liquor pH.

One thing of concern is what happens when it predicts a higher sparge pH, such as 5.5? Will that push the measured sparge pH above 6? For my process, I think the wise move is to see if I can get the the calculator below 4 for the sparge, assuming the predicted mash pH is in line.

With sparging, there are a couple of types, batch and continuous (fly) sparging. When you lower the pH of the sparge water, it cannot increase during a batch sparge. With continous sparging, the pH may rise as the wort becomes less dense (ie a lower SG of the runnings), but not if the water pH is low. You want to stay under 6 for your runnings. I hope that helps!

 

[THops]

With sparging, there are a couple of types, batch and continuous (fly) sparging. When you lower the pH of the sparge water, it cannot increase during a batch sparge. With continous sparging, the pH may rise as the wort becomes less dense (ie a lower SG of the runnings), but not if the water pH is low. You want to stay under 6 for your runnings. I hope that helps!

I batch sparge. So, I could have a reading error, but I measured the sparge liquor at 4.4 before adding to the (post mash) grain. I measured the sparge runoff at 5.45 ph. So, either I measured incorrectly (possible of course), or it seems like my sparge ph did increase?

Still not sure why the calculator predicted sparge ph of 3.9, which seems closer to the liquor ph. But if the sparge ph really WAS 3.9 or 4.4 or 5.45, it does not seem to matter, since all are below 6.

My pre-boil ph was 5.3. So when the mash and sparge water combined in the kettle, all was good.

 

[Yooper]

I batch sparge. So, I could have a reading error, but I measured the sparge liquor at 4.4 before adding to the (post mash) grain. I measured the sparge runoff at 5.45 ph. So, either I measured incorrectly (possible of course), or it seems like my sparge ph did increase?

Still not sure why the calculator predicted sparge ph of 3.9, which seems closer to the liquor ph. But if the sparge ph really WAS 3.9 or 4.4 or 5.45, it does not seem to matter, since all are below 6.

My pre-boil ph was 5.3. So when the mash and sparge water combined in the kettle, all was good.

If your water is acidified without any alkalinity added (like baking soda), the batch sparge pH shouldn't be higher than the water. Something is odd with that. When batch sparging, a large amoung of the buffers and sugars remain compared to a continuous sparge.

I guess we'd need to know the amount of alklinity remaining in your sparge water if you're not using RO water- but with a low pH like that you'd think the alkalinity would be neutralized. It really shouldn't raise the pH if batch sparging.

 

[GFHomebrew]

Measurement error maybe?

I'd test this batch sparge PH over a few brews before drawing a conclusion .

 

[THops]

If your water is acidified without any alkalinity added (like baking soda), the batch sparge pH shouldn't be higher than the water. Something is odd with that. When batch sparging, a large amoung of the buffers and sugars remain compared to a continuous sparge.

I guess we'd need to know the amount of alklinity remaining in your sparge water if you're not using RO water- but with a low pH like that you'd think the alkalinity would be neutralized. It really shouldn't raise the pH if batch sparging.

I use tap water with a starting pH of 9, if that helps.

So, let's say my sparge water really did get acidified down to 4.4 or the 3.9 the calculator predicted. I would think my sparge pH would at least raise up a little because the grain has absorbed the strike water that had a higher pH.

I guess I thought even with a batch sparge the runoff pH will rise. My mash pH was around 5.4, so a bit higher than predicted. But that is close to the reading I got from the sparge runoff.

 

[THops]

Measurement error maybe?

I'd test this batch sparge PH over a few brews before drawing a conclusion .

Which measurement? Do you think my batch sparge runoff was really 3.9 as predicted?

 

[GFHomebrew]

Which measurement? Do you think my batch sparge runoff was really 3.9 as predicted?

Exactly which is the reason for the thread

I'd be taking your batch sparge PH and comparing it to the BF prediction a few times before calling a conclusion that the predicted PH output is wrong.

I'm gunna stick with my response that the water calc will give a more reliable mash PH prediction than your batch sparge.

In the end I think you've come to the conclusion that your sparge PH isn't as important as your mash ph as all your doing is rinsing the grains this is with exception to the high sparge water PH that may extract tannins...

 

[THops]

Exactly which is the reason for the thread

I'd be taking your batch sparge PH and comparing it to the BF prediction a few times before calling a conclusion that the predicted PH output is wrong.

I'm gunna stick with my response that the water calc will give a more reliable mash PH prediction than your batch sparge.

In the end I think you've come to the conclusion that your sparge PH isn't as important as your mash ph as all your doing is rinsing the grains this is with exception to the high sparge water PH that may extract tannins...

Yes, my conclusion is the mash pH is most important, and the calculator works pretty well for that. Also that I make sure the sparge calculation is below 6.

There does not seem to be consensus on whether the sparge calculator is working for me, though. It's doesn't really matter, because my pre boil pH is good. But it's still curious to me why it predicts such a low sparge ph.

 

[GFHomebrew]

Yes, my conclusion is the mash pH is most important, and the calculator works pretty well for that. Also that I make sure the sparge calculation is below 6.

There does not seem to be consensus on whether the sparge calculator is working for me, though. It's doesn't really matter, because my pre boil pH is good. But it's still curious to me why it predicts such a low sparge ph.

I look forward to your future feedback.


Aside note I used a PH meter a few years back when I started brewing hearing all the important PH recommendations when it comes to mashing and sparging and boiling and in the end beer.

Well the probe died and with it my continued use.

I've come to the conclusion that yes I'll pay attention to bring the mash ph down and my sparge pH with a drop or two of phosphoric but after that what will be will be

Now these days though that I'm using exogenous enzymes that require a specific PH working range and using home malted Gluten free Grains I'm feeling the need for checking actual mash PH again

 

[THops]

I look forward to your future feedback.


Aside note I used a PH meter a few years back when I started brewing hearing all the important PH recommendations when it comes to mashing and sparging and boiling and in the end beer.

Well the probe died and with it my continued use.

I've come to the conclusion that yes I'll pay attention to bring the mash ph down and my sparge pH with a drop or two of phosphoric but after that what will be will be

Now these days though that I'm using exogenous enzymes that require a specific PH working range and using home malted Gluten free Grains I'm feeling the need for checking actual mash PH again

I get that... If your process is dialed in and you always hit your pH numbers, there isn't a need to do all the pH testing.

For me, I'm not quite there. I've been testing mash pH for a while now, but only recently became interested in other pH readings, such as pre boil kettle pH.

I also want to understand things, so I can make the best beer possible.

 

[GFHomebrew]

I get that... If your process is dialed in and you always hit your pH numbers, there isn't a need to do all the pH testing.

For me, I'm not quite there. I've been testing mash pH for a while now, but only recently became interested in other pH readings, such as pre boil kettle pH.

I also want to understand things, so I can make the best beer possible.

Onwards and upwards my brewing Friend!

 

[Yooper]

I use tap water with a starting pH of 9, if that helps.

So, let's say my sparge water really did get acidified down to 4.4 or the 3.9 the calculator predicted. I would think my sparge pH would at least raise up a little because the grain has absorbed the strike water that had a higher pH.

I guess I thought even with a batch sparge the runoff pH will rise. My mash pH was around 5.4, so a bit higher than predicted. But that is close to the reading I got from the sparge runoff.

The pH of the sparge water doesn't matter- it's the aklinity. What's the bicarbonate/alkalinity of that water? That's what you have to neutralize.

 

[THops]

The pH of the sparge water doesn't matter- it's the aklinity. What's the bicarbonate/alkalinity of that water? That's what you have to neutralize.

The alkalinity coming out of the tap is 61 ppm CaCo3. After treatment, the calculator shows residual alkalinity as 13.68. Is this good? The calculator shows effective strength of weak acids as 218.73 -- I have no idea what that means.

So, more data points from my brew a few days ago:

I set the calculator to 5.26 mash ph, and the resulting sparge ph prediction was 3.5.

I measured the sparge liquor ph as 3.77, and the actual sparge runoff as 5.4. So, it seems to me the calculator is showing me the sparge liquor ph, not the sparge runoff ph.

It does not seem to matter, because my pre-boil ph was 5.2.

Here is what the calculator shows. I only really understand mash ph, sparge ph, and mash thickness. Not sure what the other calculations mean.

Grist DI water pH: 5.67
Grist pH buffer: 33 mEq⋅kg-1⋅pH-1
Mash Report:
Mash pH *: 5.26 ✓Sparge pH: 3.5

Mash thickness: 1.60 qt/lb
pH Delta from Water: -0.41
effective water residual alkalinity: 13.68 ppm as CaCO3
effective strength of weak acids: 218.73 ppm as CaCO3
* mash prediction is for mash sample cooled to 25 C / 77 F

 

[Yooper]

Right- the pH of the water is pretty immaterial, but the alkalinity is what is neutralized so that your runnoff pH isn't above 6. In continuous/fly sparging that is important as tannins can be extracted when the pH is above 6 and the SG drops below about 1.020 so that's why that setting is there.
For batch sparging, it doesn't have the same impact but you also don't want the pH to be up above 6 either.

I hope that all makes sense!

 

[THops]

Right- the pH of the water is pretty immaterial, but the alkalinity is what is neutralized so that your runnoff pH isn't above 6. In continuous/fly sparging that is important as tannins can be extracted when the pH is above 6 and the SG drops below about 1.020 so that's why that setting is there.
For batch sparging, it doesn't have the same impact but you also don't want the pH to be up above 6 either.

I hope that all makes sense!

It does.

But my original question remains... What is your conclusion about the calculator showing my predicted sparge pH as 3.5? I think it really is showing sparge liquor pH, right? At least for people who treat all of their water at once...

 

[Yooper]

It does.

But my original question remains... What is your conclusion about the calculator showing my predicted sparge pH as 3.5? I think it really is showing sparge liquor pH, right? At least for people who treat all of their water at once...

Yes, that's correct.
But again, the pH of the sparge liquor is immaterial once the alkalinity has been removed.

 

[THops]

Yes, that's correct.
But again, the pH of the sparge liquor is immaterial once the alkalinity has been removed.

Immaterial as long as the sparge liquor ph is below 6...

One thing that intrigues me is how it all comes together for the pre-boil ph. In the case of my last brew, my actual measured ph was 5.36, so a bit higher than predicted from the calculator (5.26), but it was actually my target ph so all was good. The sparge runoff measured 5.4, which was also good. But how do both those higher ph's result in a pre-boil of 5.2?!

And what would happen if I did have the sparge ph calculator predicting 5.4 instead of 3.5? I have to wonder what my actual sparge runoff ph would be, and especially what my pre-boil ph would be...