RO water pH level - EZWater

This is a 3-part question:
1. If I run my tap water through an RO filter, does that lower the pH of the water?
2. If so, on the EZWater spreadsheet, when you tell it that you are using some RO or distilled water, does it adjust the pH of the water accordingly?
3. If not, does anyone else who uses EZWater have problems with getting their pH to match?

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The background:
I started diluting my tap water with RO water as needed to get my pH and minerals where they theoretically should be. I looked back through my notes and noticed an interesting trend:

Sometimes my mash pH was spot on with what the EZWater spreadsheet calculated. Sometimes it was 0.2-0.4 points lower.

I got to wondering what was causing this - I noted that the every recipe where my pH was equal to what EZWater calculated, I was using 100% tap water (treated with Campden tablets). When my pH measurements were off from what EZWater predicted, I was diluting my tap water by some % with RO water.

My notes cover 13 brew sessions since the start of the year - various recipes and batch sizes. Sometimes I use acid malt to adjust my pH as needed, sometimes not.

I am still interested to see if anyone else has any experience with the questions above, but I think I may have found (at least part of) the explanation.

EZ water uses a default "dist water pH" value of 5.70 for 2-Row. However, down in the fine print, it mentions that Rahr 2-Row has been found to have a "dist water pH" value of 5.56.

I checked with my LHBS - Rahr is the only brand of 2-Row they carry. Sure enough, all of my recipes where my measured pH matched up with EZWater, I was not using 2-Row. My recipes that were off all used 2-Row as a base. Plugging 5.56 into the spreadsheet, I come up with a closer pH to what I actually measured.

So that brings up a follow up question - is there a resource for these distilled water pH values for each grain type based on manufacturer? Or is Rahr's 2-Row just an oddity and the others are pretty standard?

RO water has no or little buffering capacity, so for the most part assume neutral ph of 7. But as it sits in the kettle it will pick up CO2 and acidify to 6-6.5. I alway use 7 though am I'm pretty darn close.

TheHappyHopper said:

I am still interested to see if anyone else has any experience with the questions above, but I think I may have found (at least part of) the explanation.

Click to expand...

Yes, running water through RO does reduce the pH somewhat but as nearly all the bicarbonate is stripped out that is insignificant.

TheHappyHopper said:

EZ water uses a default "dist water pH" value of 5.70 for 2-Row. However, down in the fine print, it mentions that Rahr 2-Row has been found to have a "dist water pH" value of 5.56.

Click to expand...

The distilled water mash pH does not depend on the pH of the distilled (or deionized or RO) water as long as most of the bicarbonate has been removed.

TheHappyHopper said:

So that brings up a follow up question - is there a resource for these distilled water pH values for each grain type based on manufacturer? Or is Rahr's 2-Row just an oddity and the others are pretty standard?

Click to expand...

The Rahr may be extreme but I have meaasured as low as 5.68 (Crisp M.O.). Base malt pH's can be all over the place and there is no central repository for information other than the couple dozen malts that Kai Troester and I have measured.

But... I had a paper published in January's MBAA TQ which begs maltsters to get this data for inclusion in their spec sheets and will be doing a poster which has the same appeal at the annual meeting this fall so keep your hopes up!

It's a little like asking how much damage the fly will inflict on the truck when it hits the windshield.

The fly is so small in comparison, it's mass can be ignored.

The alkalinity of RO water is so low (alkalinity tells us how EASILY pH is changed) that the pH itself is insignificant. The malt will have almost total control over the water. This can be a little counter intuitive at first, hence why this comes up about every day! :cheers:

What's the last thing that goes through the fly's mind when he hits?

ajdelange said:

What's the last thing that goes through the fly's mind when he hits?

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"I wish I could land on one more person's cheeseburger at a BBQ."

ajdelange said:

What's the last thing that goes through the fly's mind when he hits?

Click to expand...

His eyes?

His a*****e.