pH meter and bru'n water

[hopbrad]

I never tested my pH until my last brew day as we got a milwaukee pH55 meter. We calibrated it with the 2 solutions about 5 days prior to brew day and then stored it in RO water.
My store bought water is reading 8.0 which I thought seemed high for RO, but after a quick search, I guess its not unusual.

Brew day was for Belgian Wit, per bru'n water with my grain bill, acid malt and mineral additions, says my pH should be 5.48

I took my reading and it was at 6.

To get to an acceptable level, I added acid (citric acid) to get the mash pH down. I ended up using .3 grams/gal and a pH of 5.6.
After brew day, I came back and adjusted my additions in Bru'n water and it is saying my pH should of been 5.3.

Notes - I didn't realize you need to take pH readings at room temp, so this was at mash temp. Is this why it is so skewed?

Thoughts?

 

[Yooper]

Make sure you take the readings at room temp- not only does it skew the readings (by about .3 if I remember right), but it will more quickly ruin your expensive probe.

Also, calibrate your meter right before brewing, and then check it in the buffers during that time, to make sure it's not drifting.

 

[JonM]

Online calculators get you in the ballpark; I don't think they're intended to be a spot on predictor because of variables in the lovibond of the grains, etc.

And I think you want to calibrate your meter right before using it. Five days might be a little too long between calibration and use.

 

[xpops]

very likely. I also think that higher temps can potentially damage the prob on some pH meters. I would maybe do some more calibrations and tests before next brew day to ensure your prob is still ok!

I typically calibrate while strike water is heating up, so it's ready to pull a sample shortly after mashing. As others have said - 5 days prior is a little too long to get an accurate calibration.

 

[TheHopfather]

Like everyone has said above, test your mash pH at room temps. The higher mash temp will skew your readings, about 0.3, but the higher temp sample will be 0.3 pH lower than the room temp sample. So your reading of 6.0 pH was more likely 6.3 pH at room temp.

Second, calibrate your meter right before using it. Store it in the 4.0 buffer while you're waiting for the sample to cool. Double check the readings in the buffers to ensure you are calibrated correctly before testing the sample.

Third, Brun Water and such will get you close, but they aren't guaranteed to be spot on every time. There are variations in the grain (company, grain type, process, etc), also your RO water might not be as pure as you think. Have you tested the water with a TDS meter? If you scroll waaay down on the "Water Adjustment" tab in Brun Water you'll see a section labeled "Dilution Water Profiles". The profile for RO has an alkalinity value of 13 ppm, your RO water may have more alkalinity than that, which means more acid is required.

It is important to remember that testing mash pH takes place at room temps. All of the quoted pH ranges are for room temp samples as that is the laboratory standard. The actual pH during the mash will be lower than what you are reading on your pH meter, but you are worried about the room temperature values. Take a look at this link for more info;

http://braukaiser.com/blog/blog/2011/03/02/about-ph-targets-and-temperature/

Braukaiser says it better than I can.

 

[hopbrad]

Great, thanks for all the tips. ill have to get some more solution to re-calibrate.
I also didn't realize it was needed to calibrate so often so we used the entire packet of 7.01 and 4.01 solution that came with it figuring it was a 1 time thing.
Unfortunately that will take a month or 2 to get my hands on their product in my location. Unless there is another common product that could be used to calibrate a meter? Maybe something at at a pool supply store.

 

[JonM]

You can order this stuff online. (Watch for Mem. Day sales.)

http://www.northernbrewer.com/buffer-solution-ph-4-01-220-ml

 

[mabrungard]

I never tested my pH until my last brew day as we got a milwaukee pH55 meter. We calibrated it with the 2 solutions about 5 days prior to brew day and then stored it in RO water.
My store bought water is reading 8.0 which I thought seemed high for RO, but after a quick search, I guess its not unusual.

Brew day was for Belgian Wit, per bru'n water with my grain bill, acid malt and mineral additions, says my pH should be 5.48

I took my reading and it was at 6.

To get to an acceptable level, I added acid (citric acid) to get the mash pH down. I ended up using .3 grams/gal and a pH of 5.6.
After brew day, I came back and adjusted my additions in Bru'n water and it is saying my pH should of been 5.3.

Notes - I didn't realize you need to take pH readings at room temp, so this was at mash temp. Is this why it is so skewed?

Thoughts?

Many things wrong here.

Calibration MUST be performed just prior to usage. You can't calibrate a few days before.

You can't store any pH probe in contact with relatively pure water. That will deplete the probe of its internal electrolytes and eventually destroy it. Use a storage solution to keep your probe in top shape or seal your probe in a chamber with a drop or two of water to keep the probe hydrated.

If RO or distilled water is used without first checking its TDS reading, you can't be sure it was actually as pure as assumed. RO machines are notorious for failing and delivering water that isn't pure enough. Get a TDS meter.

Never insert a pH probe into water or wort that is more than 20 to 30 degrees above room temperature. The thermal stress on the thin glass bulb will destroy it.

 

[ajdelange]

It's not quite so dramatic as all that. Inserting a pH probe into hot wort or mash won't destroy it. But it will subject it to thermal stresses it can well do without. The result is a shorter probe life.

The pH of the source water really isn't relevant. What is is its alkalinity. pH 8 is quite high for RO water. As it is pretty much ion free carbon dioxide dissolved in it from the atmosphere usually pulls its pH down into the 6's.

 

[hopbrad]

Thanks both! Looks like I'm SOL for this meter. I dont think I'll be able to get a storage solution or new calibration solutions anytime soon in my area of the world.

There is only 1 company that delivers water out to my area. It's RO/Mineral water that is reported to have 8 mg/L of Magnesium and 25 mg/L of calcium.
Plugging this into Bru'n water, my beer is super consistent using this water along with acidulated malt/mineral additions. I'll give it a try next brew day with the mash at room temp and report results, altho I wont rely on the meter to change the pH after the fact since I have not stored or calibrated the meter correctly.

Thanks again for the help

 

[spreemotion]

I wanted to follow up on a couple similar questions I had. In my case 100% RO Water, measured 8.0 PH level, however when I type my water profile additions into Bru'n water is has me at, 5.15 and EZ water has me coming in at 5.39. I know my system extremely well and my room temp mash the last 3 batches has came in at, 5.58ish everytime. Anything I might be missing why Bru'n water has me drifting so much? I really want to use it, its really solid XLS calculations.

I completely understand these calculations are rough, however that just seems somewhat skewed. I do need to test with a TDS meter though, good point above.

 

[ScrewyBrewer]

I wanted to follow up on a couple similar questions I had. In my case 100% RO Water, measured 8.0 PH level, however when I type my water profile additions into Bru'n water is has me at, 5.15 and EZ water has me coming in at 5.39. I know my system extremely well and my room temp mash the last 3 batches has came in at, 5.58ish everytime. Anything I might be missing why Bru'n water has me drifting so much? I really want to use it, its really solid XLS calculations.

I completely understand these calculations are rough, however that just seems somewhat skewed. I do need to test with a TDS meter though, good point above.

If you included the grain bill and mash thickness, for the recipe you used, it would be helpful when trying to debug the discrepancies mentioned.

 

[ScrewyBrewer]

It's RO/Mineral water that is reported to have 8 mg/L of Magnesium and 25 mg/L of calcium.

IMO it can be either RO, or mineral water, but not both.

 

[ajdelange]

In my case 100% RO Water, measured 8.0 PH level

Unless the water feeding the RO system is highly alkaline the pH of the permeate should be in the 6's. This is because tyically the alkalinity of RO water is very low to the point that carbonic acid from the CO2 in the air is sufficient to lower its pH.

however when I type my water profile additions into Bru'n water is has me at, 5.15 and EZ water has me coming in at 5.39.

I assume this means that when you specify you grist and RO water to the program it predicts pH in this range. As the pH of the water itself has little effect on the pH of the mash (and I don't believe Brun Water handles those small effects) what you are seeing is perfectly normal.

I really want to use it, its really solid XLS calculations. I completely understand these calculations are rough,

??

 

[ajdelange]

IMO it can be either RO, or mineral water, but not both.

Lots of stores have machines that produce RO to which they add some minerals for flavor. I think that's what he means. Note that I hadn't noticed this in my previous post. Post treatment mineral addition may explain the high pH of this 'RO' water.

 

[spreemotion]

Mostly 2 row and vienna with some crystal 40.

Total Grist Weight, 14.5 lb
Water to grist ration 1.79 (QTS/lb).

On the water adjustment tab the percent Dilution Water is set to 100%. I must be missing something obvious here, thanks for your response...

"I assume this means that when you specify you grist and RO water to the program it predicts pH in this range. As the pH of the water itself has little effect on the pH of the mash (and I don't believe Brun Water handles those small effects) what you are seeing is perfectly normal."

No, seeing I just got a new PH meter been really trying to focus on this. When I add the applicable water profile additions (chloride, gypsum, etc), that is when it goes a little low. However every brew I see the actual PH during mash at a consistent level.

 

[spreemotion]

"Unless the water feeding the RO system is highly alkaline"

This could very likely be in my scenario.

 

[mabrungard]

Mostly 2 row and vienna with some crystal 40.

Total Grist Weight, 14.5 lb
Water to grist ration 1.79 (QTS/lb).

On the water adjustment tab the percent Dilution Water is set to 100%. I must be missing something obvious here, thanks for your response...

"I assume this means that when you specify you grist and RO water to the program it predicts pH in this range. As the pH of the water itself has little effect on the pH of the mash (and I don't believe Brun Water handles those small effects) what you are seeing is perfectly normal."

No, seeing I just got a new PH meter been really trying to focus on this. When I add the applicable water profile additions (chloride, gypsum, etc), that is when it goes a little low. However every brew I see the actual PH during mash at a consistent level.

Unless you are measuring your mashing pH with a freshly calibrated pH meter, you could easily observe a difference there. But an equally important factor is that RO machines do eventually fail and they allow higher concentrations of the raw water's mineral content into the 'RO' water. A very good way to assess if this is happening, is to check the TDS reading of the RO water. If its above 25 to 50 ppm TDS, the machine is probably failing. It should go without saying, that you aren't getting what you're paying for and that also means that a brewing calculator like Bru'n Water won't predict very well.

Make sure your RO water is actually RO quality!

 

[ajdelange]

It's RO/Mineral water that is reported to have 8 mg/L of Magnesium and 25 mg/L of calcium.

I think this is the key. Apparently it is RO water to which some minerals have been added. This would explain (if some of mineral were magnesium and/or calcium carbonate or magnesium or calcium hydroxide) the high pH and introduce alkalinity.

 

[hopbrad]

Lots of stores have machines that produce RO to which they add some minerals for flavor. I think that's what he means. Note that I hadn't noticed this in my previous post. Post treatment mineral addition may explain the high pH of this 'RO' water.

yes exactly that, my understanding is that it is RO water with Minerals added back in.

 

[spreemotion]

Thanks much for your response, everyone for that matter. I stopped at 2 other places on the way home and ran those RO stations into smaller sampling sizes and sure enough those are coming in around 6.05-6.25

Did not see this in the spreadsheet, what does Bru'n water use as a default value for "generic" RO water PH?

Check that already found it, thanks guys!
"RO water pH has virtually no effect on the resulting mash pH. We are talking about altering mashing pH by a hundredth when the RO pH changes by a whole unit.

The most important thing is the alkalinity of the water. In the case of good RO water, that alkalinity should be very low."

 

[Silver_Is_Money]

My homes RO water measures in at 6.08 pH.

 

[mabrungard]

Remember, water pH has very little effect on mashing and wort pH. Alkalinity is the main concern.

 

[Mirilis]

tell you wife you need an under sink RO water system so you guys can use it for stuff around the house and to help replace buying bottled water. At $4 a case it will pay itself off in about 30 cases

Then when shes not looking use it to slowly fill up jugs of water for brewing (it takes a while because they usually only have a 3 gallon tank and take a while to fill)

Im usually within +/- 0.03 of my expected mash pH consistently

 

[skidmark]

tell you wife you need an under sink RO water system so you guys can use it for stuff around the house and to help replace buying bottled water. At $4 a case it will pay itself off in about 30 cases

Be aware that the reject flow can be 5-8 times the product produced. Expect higher water bills, along with membrane replacement, etc. when figuring your costs.

 

[ajdelange]

That is true of the inexpensive under the sink systems. Systems in which you have control over the concentrate outlet orifice can achieve 1:1 output ratios provided that the feed water is relatively low in bicarbonate. Even better recoveries than that can be had at the expense of some rejection performance.

 

[skidmark]

... provided that the feed water is relatively low in bicarbonate.

Not with my "drywall on tap" ...

 

[ajdelange]

That would be permanent hardness i.e. sulfate rather than bicarbonate (temporary hardness). Permanent hardness can be a problem as it limits allowable recovery too but not so much of a problem as temporary hardness. People who want high recovery from waters containing calcium and magnesium install a water softener before the RO unit.

 

[Mirilis]

I was on well water when I had my under the sink system so I can care less about my water bill since it didn't exist

 

[ArcaneXor]

tell you wife you need an under sink RO water system so you guys can use it for stuff around the house and to help replace buying bottled water. At $4 a case it will pay itself off in about 30 cases

I am not a big fan of under-the-sink systems for brewing since the tanks tend to be very small and the back pressure makes them slow to fill. A much better option (in my opinion) is to equip your RO system with an auto shut-off valve and use a large food-grade plastic container with a spigot and float valve as your tank. I always have 15 gallons of RO water ready to use in my utility room. It takes me about 90 seconds to fill up a keg this way. I also recommend getting a pressure gauge and TDS meter for an RO system. The pressure gauge can identify issues with the ASOV, and the TDS meter is great to verify that the membrane is in working order.