Mash PH is always 5.0 ?

[Devils_Chariot]

Almost 90% of the time my mash PH is 5. Despite what ezwater or brunwater tells me. I use RO water that I make from tap. The dissolved solids is 2 or less and the PH is 4.7. Most grain bills ar 2 row, carapils, and wheat or vienna. Not a lot of dark malts.

I cool the wort sample so I am reading around room temp and I do a test from the hot wort and convert for temperature. I have taken the ph reading through out the mashing process 10, 20, and 30 minutes. Always the same readings.

I have reverse engineered how to get accurate predictions from ezwater by putting a value of 10 under the Lactic Acid additions. However, I feel like this is just a band aid.

Can anyone help shed light on whats happening. I don't know if I need to change an input for RO water besides saying I am using 100% RO water. Is there possibly something else going on or that I am doing wrong?

Help!

 

[JLeuck64]

I gotta ask how you are measuring pH? Using a meter or those ineffective strips? I just tried those stupid strips for the first time last weekend and got the same kind of results... seriously thinking about returning them!

 

[Devils_Chariot]

I am mostly using colorphast strips. I used to use a ph meter but i gound strips are easier. I read up on how to use them on the forum. I have also used the calibration solutions for the meter to test the strips and they are accurate.

 

[joshesmusica]

So the ph of your ro water is 4.7 before doing anything to it? That's the first part that would be a bit concerning for me.
Is it a new ro system?

How's your efficiency been doing? Are you ending up with lower than expected FGs even if you're mashing 152 and above? I ask because at 5.0 you're starting to get to the point that the alpha amylase isn't working as much as the beta, which would give you more simple sugars from your mash.
If your efficiency is doing ok, and all your outcomes are as predicted by a recipe calculator, then I would assume the reading is wrong.

Here's a nice experiment that shows why people prefer not to use the strips when measuring a mash ph:

http://braukaiser.com/wiki/index.php?title=ColorpHast_vs_pH_meter

 

[The_Bishop]

The PH of your starting water is completely irrelevant. Especially a very low alkalinity water like RO.

 

[dmtaylor]

So the ph of your ro water is 4.7 before doing anything to it? That's the first part that would be a bit concerning for me.

This. I figure something must be wrong with your measurement method, whether it's the strips themselves, or the technique, or who knows. Try a different method.

 

[ajdelange]

Almost 90% of the time my mash PH is 5. Despite what ezwater or brunwater tells me. I use RO water that I make from tap. The dissolved solids is 2 or less and the PH is 4.7.

No, it isn't. It would be, at lowest, about 5.6 if the RO system were perfect (removed everything). Given that it doesn't pH will probably be in the low 6's. There is something wrong with the way you measure pH.

Most grain bills ar 2 row, carapils, and wheat or vienna. Not a lot of dark malts.

If you are not adding any lactic acid or sauermalz, your mash pH's are going to be around 5.6.

I cool the wort sample so I am reading around room temp and I do a test from the hot wort and convert for temperature. I have taken the ph reading through out the mashing process 10, 20, and 30 minutes. Always the same readings.

Further evidence that your pH readings are flawed.

I have reverse engineered how to get accurate predictions from ezwater by putting a value of 10 under the Lactic Acid additions. However, I feel like this is just a band aid.

If you are having the calculator add 10 (units?) of lactic acid to force it to produce your invalid readings then you have not 'reverse engineered it to get accurate predictions'. You have reengineered it to produce inaccurate predictions which match your inaccurate readings.

Can anyone help shed light on whats happening. I don't know if I need to change an input for RO water besides saying I am using 100% RO water. Is there possibly something else going on or that I am doing wrong?

Yes, you say what you are doing wrong in a later post:

I am mostly using colorphast strips.

That's the problem right there. You cannot use strips for brewing. They simply don't work. I'm not sure anyone really knows why but my personal guess is that the wort stains the dye pad. When Kai Troester did his experiments (mentioned in another post here) he asked me to participate and sent me images of strips and legend. This is like asking John Milton to read your poetry because I am color blind so I used the color meter on my computer to measure the colors of the test strips and the legend. The colors of the test strips did not lie on the curve connecting the colors in the legend. Thus the user is confronted with the task of matching test colors that don't lie in the color space of the legend. Little wonder readings are inaccurate.

I used to use a ph meter but i gound strips are easier.

As is the case with so many other things in life the easiest path often leads to trouble.

I read up on how to use them on the forum.

There are no instructions available on how to use the to obtain accurate readings as you can't. You apparently missed those posts that advocate adding 0.3 to all readings. That would get you closer to realistic mash pH (5.3) but still not all the way there.

I have also used the calibration solutions for the meter to test the strips and they are accurate.

They are reasonably accurate when reading buffers. They are not accurate with wort.

 

[mabrungard]

No, it isn't. It would be, at lowest, about 5.6 if the RO system were perfect (removed everything).

AJ, I'm hoping you are aware that dissolved gases pass freely through RO membranes. As you are aware, some water sources do have a significant dissolved CO2 content and with the concentrating effect of RO, the product water can easily be supersaturated with CO2. That can drive down the water pH much lower than 5.6.

Where excessive CO2 content in water is a problem, we typically send the RO product through an air-stripping tower to remove the excess gas.

 

[ajdelange]

Yes, I am aware of that and if the source water was super saturated (or even close to it) and he goes into a pressure tank then the water could stay supersaturated but what happens when a sample is drawn? If you've ever done an alkalinity test you know how careful you have to be in handling the sample in order to prevent it from moving towards equilibrium with the air before you get it to the lab and you have probably wondered what to write down for sample pH as the meter reading climbs before your very eyes while you are setting up the titration.

That's not what is happening here.

But I'd be curious as to what typical pH's are out of a pressure tank RO system (I have an atmospheric tank before my pressure tank) so how about someone going out and taking a few meausrements. Note: it's tricky measuring pH on low ionic strength solutions.

 

[Devils_Chariot]

No, it isn't. It would be, at lowest, about 5.6 if the RO system were perfect (removed everything). Given that it doesn't pH will probably be in the low 6's. There is something wrong with the way you measure pH.

If you are not adding any lactic acid or sauermalz, your mash pH's are going to be around 5.6.


Further evidence that your pH readings are flawed.

If you are having the calculator add 10 (units?) of lactic acid to force it to produce your invalid readings then you have not 'reverse engineered it to get accurate predictions'. You have reengineered it to produce inaccurate predictions which match your inaccurate readings.



Yes, you say what you are doing wrong in a later post:



That's the problem right there. You cannot use strips for brewing. They simply don't work. I'm not sure anyone really knows why but my personal guess is that the wort stains the dye pad. When Kai Troester did his experiments (mentioned in another post here) he asked me to participate and sent me images of strips and legend. This is like asking John Milton to read your poetry because I am color blind so I used the color meter on my computer to measure the colors of the test strips and the legend. The colors of the test strips did not lie on the curve connecting the colors in the legend. Thus the user is confronted with the task of matching test colors that don't lie in the color space of the legend. Little wonder readings are inaccurate.

As is the case with so many other things in life the easiest path often leads to trouble.


There are no instructions available on how to use the to obtain accurate readings as you can't. You apparently missed those posts that advocate adding 0.3 to all readings. That would get you closer to realistic mash pH (5.3) but still not all the way there.

They are reasonably accurate when reading buffers. They are not accurate with wort.

Sorry I asked.

 

[The_Bishop]

But I'd be curious as to what typical pH's are out of a pressure tank RO system (I have an atmospheric tank before my pressure tank) so how about someone going out and taking a few meausrements. Note: it's tricky measuring pH on low ionic strength solutions.

I've got a shiny new Milwaukee MW102 on the way, should be here Sunday. I also have an RO system with a pressure storage tank, so I'll be happy to oblige.

 

[Devils_Chariot]

So the ph of your ro water is 4.7 before doing anything to it? That's the first part that would be a bit concerning for me.
Is it a new ro system?

How's your efficiency been doing? Are you ending up with lower than expected FGs even if you're mashing 152 and above? I ask because at 5.0 you're starting to get to the point that the alpha amylase isn't working as much as the beta, which would give you more simple sugars from your mash.
If your efficiency is doing ok, and all your outcomes are as predicted by a recipe calculator, then I would assume the reading is wrong.

Here's a nice experiment that shows why people prefer not to use the strips when measuring a mash ph:

http://braukaiser.com/wiki/index.php?title=ColorpHast_vs_pH_meter

I batch sparge and my efficiency is a consistent 65%.

I have seen Kai test before and reviewing it now I see.03 variance could be troublsome.

I'm going to go retest with my PH meter. We'll see if that confirms or voids the phenomenon.

 

[passedpawn]

Sorry I asked.

Uh... why? I think "thanks" would have been a more appropriate response.

 

[joshesmusica]

I batch sparge and my efficiency is a consistent 65%.



I have seen Kai test before and reviewing it now I see.03 variance could be troublsome.



I'm going to go retest with my PH meter. We'll see if that confirms or voids the phenomenon.

I'm glad Martin and aj found this and chimed in. They're the water experts, so listen to them, not me.

Actually guys, this thread got me thinking, with the different compounds coming from the grains, if one started out with a ph lower than 5 would it actually raise it instead of lowering it?

 

[normonster]

Sorry I asked.

Sorry you asked? You just got good advice from water experts....more than one! These guys literally contributed to the waterbook. There is no better advice to be had. Any tone of condemnation you have perceived is not part of their agenda in answering your post.

You pretty much need to get a nice pH meter and do all your tests again.

Cheers!

 

[ajdelange]

That's not what is happening here.

At least I don't think it is but it would be easy enough to see. OP should pour water back and forth between a couple of glasses to get it close to air equilibrium. If the pH when he does that is higher than when he tests straight out of the tank then indeed some CO2 is entrained.

 

[ajdelange]

Actually guys, this thread got me thinking, with the different compounds coming from the grains, if one started out with a ph lower than 5 would it actually raise it instead of lowering it?

Not completely sure I understand the question but I think I do. A mash is a mix of several components. Each has what I call it's 'intrinsic pH'. This is the pH you would measure if you stuck a pH meter electrode into the isolated component. It is obvious what it means in terms of the water and liquid acids or bases the brewer might add but what about the grains or powdered salts? In this case it means the pH of a solution or suspension of that material in deionized water.

When you mix the mash components thoroughly and wait a few minutes the mixture comes to some pH we sometimes call pHz. pHz will between the lowest intrinsic pH and highest intrinsic pH of the set of mash components. Added acids or acidified malts or black malts (low intrinsic pH) will yield up protons and in the process their pHs will increase. Conversely, the high intrinsic pH components absorb the released protons causing their pH's to rise. At pHz the total of absorbed protons just equal the total of released protons.

 

[joshesmusica]

Not completely sure I understand the question but I think I do. A mash is a mix of several components. Each has what I call it's 'intrinsic pH'. This is the pH you would measure if you stuck a pH meter electrode into the isolated component. It is obvious what it means in terms of the water and liquid acids or bases the brewer might add but what about the grains or powdered salts? In this case it means the pH of a solution or suspension of that material in deionized water.



When you mix the mash components thoroughly and wait a few minutes the mixture comes to some pH we sometimes call pHz. pHz will between the lowest intrinsic pH and highest intrinsic pH of the set of mash components. Added acids or acidified malts or black malts (low intrinsic pH) will yield up protons and in the process their pHs will increase. Conversely, the high intrinsic pH components absorb the released protons causing their pH's to rise. At pHz the total of absorbed protons just equal the total of released protons.

Ok so in the OP's case, he's not really using many specialty malts, so then if one was to use mainly just "base" malts (such a confusing term in a discussion about brewing water), would that effectively raise a ph of say 4.7, up to above 5? I thought I read somewhere (maybe you said it?) that base malts have a pH of around 5.8?

 

[ajdelange]

Yes. Lets suppose a brewer has water with alkalinity of 2 mEq/L and 1 mEq/L calcium hardness at pH 8.1 and he wants to mash 7 kg of Weyermanns Pilsner malt to pH 5.5 and asks me how much lactic acid he'd need. I tell him he'll need 6.05 mL 88% acid. Suppose he adds that acid to his water, decides to check the pH and is alarmed to find that its pH is 3.9. Will the malt, he wonders be able to pull the pH of the water up to anything like proper mash pH. The answer is yes. The mash pH goes to 5.5. The acid gives up 69.6 mEq protons and the calcium in reacting with phosphate supplies another 2.8. The bicarbonate in the water absorbs 35 and the malt absorbs 36.6.

 

[normonster]

AJ must have an office day today...straight spilling the knowledge! This is grand.

 

[The_Bishop]

But I'd be curious as to what typical pH's are out of a pressure tank RO system (I have an atmospheric tank before my pressure tank) so how about someone going out and taking a few meausrements. Note: it's tricky measuring pH on low ionic strength solutions.

This is a bit late, but here it goes, tested with a brand new, freshly calibrated and tested MW102:

Feed water to RO system: 6.81
RO permeate from pressure tank: 6.43

 

[Devils_Chariot]

I dont have a tank for my RO. I just run it into a cooler the night before I use it. However, I do have a regular filter inline just ahead of the RO that I put there as a rough filter. It has an activated charcoal filter insert. Is it possible I am getting any kind of pickup or transfer of ions there? The water pressure is 120 psi.

 

[ajdelange]

This is a bit late,

No, not at all.

Feed water to RO system: 6.81
RO permeate from pressure tank: 6.43

Thanks.