All RO Water is not created equal (HELP!!)

[keggert]

So, long story short I recently moved from NM to MI. I was brewing with RO water while in NM and thought I had a good handle on it for most of my beers. When I decided I'd be headed to MI I figured I'd just find a source for RO water and I'd be back on track no problems. WRONG

In NM I used AJ's water primer and life was good.

Brewed my first batch this past week in MI and my starting PH of the RO water is 4.9, before mashing. I mixed some of my well water with the RO just to get the PH up and got it the 5.1 during the mash. Figured maybe that RO machine was bad went to a different one today and that one reads 5.1. So any help on where to go from here would be a great help.

Oh and the PH readings were taken with a Hach pocket pro+ calibrated before readings and doubled/tripled check when I saw the readings I got.

Thanks in advance,

Kevin

 

[MGamber]

RO filters particulates, it doesn’t adjust pH. I’d say draw off some water every now and then over a few days and, if it doesn’t move, there’s your base line. Add something base to bring the pH up a bit and you’re golden.

 

[bracconiere]

just add some bicarb to it? has your malt changed?

edit: sorry i had to re read....4.9? before mashing? is that safe to drink? lol

 

[ScrewyBrewer]

Since RO water has no buffering taking a pH reading of it adds no real value. Your well water has buffering so mixing it with your RO water and taking a pH reading is like taking a pH reading of just your well water.

 

[Silver_Is_Money]

Good RO water will be acidic and at roughly pH 5.5 due to the CO2 in the air combining with the water to form carbonic acid. But this is of no concern. There are not enough ions of carbonic acid present within RO water to buffer against anything, so they (and the low pH that they bring along with them) can be fully ignored. The acid ions in RO water will not move a mash pH. There simply aren't enough of them, and they are dwarfed many times over by the acids within the grist.

Due to there being so few ions, you may need to let a pH meter sit in RO water for about 10 minutes undisturbed (no stirring allowed, lest you drive the pH down via inducing stirring error) before it will be 100% stable and accurately reflect the pH of the RO water.

The no stirring and long sitting time advice is also applicable to taking more honest mash pH readings.

 

[Dgallo]

So, long story short I recently moved from NM to MI. I was brewing with RO water while in NM and thought I had a good handle on it for most of my beers. When I decided I'd be headed to MI I figured I'd just find a source for RO water and I'd be back on track no problems. WRONG

In NM I used AJ's water primer and life was good.

Brewed my first batch this past week in MI and my starting PH of the RO water is 4.9, before mashing. I mixed some of my well water with the RO just to get the PH up and got it the 5.1 during the mash. Figured maybe that RO machine was bad went to a different one today and that one reads 5.1. So any help on where to go from here would be a great help.

Oh and the PH readings were taken with a Hach pocket pro+ calibrated before readings and doubled/tripled check when I saw the readings I got.

Thanks in advance,

Kevin

You could always adjust it with some baking soda. Did you plug your recipe and water info into bru’n water?

 

[Lefou]

Much better off using calcium carbonate (lime) for alkalinity adjustments for low pH drinking water. About a teaspoon/5 gallons should be about right to raise your pH.
Bicarbonate of soda works great as an alkalinity booster and pH adjustment for pool water but it will leave extra sodium you may not want in drinking water.

 

[keggert]

I know the starting PH of water doesn't effect the mash PH my reading was for reference. When I saw it was lower then what I wanted for a mash PH I will admit I panicked. I did make the error of splashing the PH meter around in the testing glass, lessoned learned. If I let it set undisturbed for 5-10 minutes the reading does come up to 5.5ish.

I've never used bru'n water as I guess I lucked out and had decent water at last location, by shear luck. Think I'll download a copy and mess around with it and see if I can make it work.

Think I'll send a sample of the well water for analysis as well, you never know it might be alright for brewing. Starting over when you think you have a handle on everything blows.

 

[mabrungard]

Brewed my first batch this past week in MI and my starting PH of the RO water is 4.9, before mashing. I mixed some of my well water with the RO just to get the PH up and got it the 5.1 during the mash. Figured maybe that RO machine was bad went to a different one today and that one reads 5.1.

As mentioned, water pH is meaningless in brewing. In addition, pH measurement in a very low ionic concentration solution like RO or distilled water is difficult and tenuous.

Its best to understand what's in the water and make water adjustments that produce the results wanted in the resulting beer. The tool to use for assessing if RO water is adequately pure, is a TDS meter (total dissolved solids). The tools to use for brewing water adjustment are either prior experience or a reliable brewing water chemistry calculator.

Understand that ALL brewing requires acid for producing a desirable mashing and wort pH. Whether acid from roast or crystal malt, biologic acid, or acid addition, brewing with a typical base malt requires acid.

PS: RO removes more than 'particulates'. Dissolved ions are not particulates.

 

[ScrewyBrewer]

The no stirring and long sitting time advice is also applicable to taking more honest mash pH readings.

Interestingly this doesn't seem to apply to all pH meters. According to the HANNA SOP gentle stirring is recommended for accurate pH readings.

 

[Silver_Is_Money]

Interestingly this doesn't seem to apply to all pH meters. According to the HANNA SOP gentle stirring is recommended for accurate pH readings.

The technical terminology is "stirring effect". The effect is:

A calibration curve obtained under stirring will give a higher than 59 mV/pH slope, because the stirring spins off counter-ions in the TL making the positive potential higher and the negative potential lower [29, 35]

This means a false slope and thereby a false high acidity reading (which means a false low pH reading).

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3933894/

Some meters may apply the slope altering mathematical formula discussed within this technical article in an attempt to negate the "stirring effect" induced increase in positive potential. If that is the case, then calibration and all readings must be taken while under an identical level of mild stirring.

 

[Silver_Is_Money]

I'm rapidly coming to the opinion that mash pH reading should always be taken with two pH meters manufactured by different companies in order to gain a level of additional statistical confidence in the samples actual pH reading.

 

[homebrewfinds]

I'd pick up a TDS meter to double check your water.

 

[ScrewyBrewer]

I recently changed the sediment, carbon block and RO membrane on my filter. After the change the inlet water TDS reading was 185 and the RO outlet TDS reading was 5. Having a TDS meter is a very convenient way of monitoring your water source.