R/O water with ph 5 resulting in mash ph too low.

[crippled1]

The ph of my R/O water is always 5. My mash ph is usually aroud 5.
I measure ph with both colorphast 0-14 and 4-7 test strips.
It doesn’t matter whether I am making a dark or light beer the ph is 5.
I use Brewers friend water calculator and usually use either light colored and hoppy or balanced profile to build my mash water. I do BIAB and do not sparge.
It seems to me the best addition to raise ph is to add slaked lime.
My concern is this raises the amount of calcium above my target of 80-100.
Is this going to be a problem?

 

[HighVoltageMan!]

1. The strips aren’t very accurate, a calibrated pH meter would be better to get the most accurate numbers.

2. The pH of the water isn’t really impactful unless it contains high alkalinity or has a good amount of buffering capacity. RO water is very low in minerals and would not have much in the way of buffering capacity, and less of an impact on pH. The grain (calcium and phosphate) would be the main driver of lower pH.

It is hard to add alkalinity to water, but you can with pickling lime. Baking soda works too, but adds sodium.

Typically I’m not to concern with a lower pH, but it may not work for you. Water is can be complicated, but most of the time some RO with a little adjustments work really well. I’m sure others who are sharper than me can chime in too.

 

[ScrewyBrewer]

Untreated RO water, with no salt or mineral additions added, will always show a low pH reading. That's because RO water has no buffering to prevent the pH from dropping.

 

[DuncB]

I'd build my Water profile for my desired brew with salts and input my grains.
I'd check the pH about 10 minutes into the mash and adjust based on that reading. Ignoring the pH of the RO water as mentioned it doesn't have the buffers.

 

[TheMadKing]

I'll second the ph strips being your problem. If you're always getting the same pH no matter what, your measurements are definitely the problem.

Get a pH meter and learn how to calibrate it and use it correctly. Take a sample of wort 10 mins into the mash and cool it to room temperature and then measure the pH of that sample.

You almost never need to raise the pH of a mash except with very dark beers sometimes.

 

[IslandLizard]

If you're using RO water, you know the mineral/alkalinity content, it's zero or close to zero.
Any (decent) brewing water calculator will then give you a close prediction of the mash pH which you can tweak with your added minerals/salts/acids. There's very little need to even measure the actual mash pH.

If you do want to measure the mash pH, do so at the end of the mash. It's usually too late to tweak it while the mash is progressing, anyway. When in doubt perform small 4-8 oz test mashes with your intended, representational, grain ratio in the grist mix.

 

[BrewnWKopperKat]

A couple of years ago, when I started with BAIB batches ...

R/O water

+

https://www.bertusbrewery.com/2012/02/water-chemistry-how-to-build-your-water.html

+

Brewers friend water calculator

=

an estimated mash pH in the right range.

There are a couple of other easy-peasy approaches (when using RO water) as well.

 

[crippled1]

For some stupid reason that water calculator defaults the source water ph to 8 I can change it to 5 but it wont save it and it defaults back to 8. So the expected ph according to the calculater is inaccurate.
I just did a brew using 5 gallons of sparkletts spring water which has some minerals and my mash ph was in the acceptable range and this was using my test strips so they are reading correctly.
I will get a meter just to check it.

 

[Bobby_M]

The pH of the source water does not matter so don't spend any time trying to make it work. I would focus on the performance of the RO system and test the output with a very cheap TDS meter.

 

[mabrungard]

The pH of a mash is quite variable during the early stages of a mash. The pH of the mashing water initially dominates the indicated wort pH until the buffering of the grain is slowly released and attained. With that release, wort pH goes toward it's long-term (equilibrium) pH value.

If you grind your grain very fine, your mashing pH should reach its equilibrium pH in about 30 minutes. For us mere mortals with coarser grinds, it will take about 45 minutes for mashing pH to reach its equilibrium.

With that said, it should be very apparent that an early mash pH measurement is essentially useless. If you're brewing a pale beer, early pH measurements are likely to be under your pH target and pH should rise during the mash. The opposite tends to be true if you've boosted the alkalinity or pH of mashing water for dark beer brewing...pH falls during the course of the mash.

 

[HighVoltageMan!]

The pH of a mash is quite variable during the early stages of a mash. The pH of the mashing water initially dominates the indicated wort pH until the buffering of the grain is slowly released and attained. With that release, wort pH goes toward it's long-term (equilibrium) pH value.

If you grind your grain very fine, your mashing pH should reach its equilibrium pH in about 30 minutes. For us mere mortals with coarser grinds, it will take about 45 minutes for mashing pH to reach its equilibrium.

With that said, it should be very apparent that an early mash pH measurement is essentially useless. If you're brewing a pale beer, early pH measurements are likely to be under your pH target and pH should rise during the mash. The opposite tends to be true if you've boosted the alkalinity or pH of mashing water for dark beer brewing...pH falls during the course of the mash.

I guess I have observed something different, although I brew mostly pale beer. I don't measure mash pH until 10 minutes, mostly because I haven't had a chance to do it and I figure it will take some time for the mash settle into it's pH. The difference in pH from 10 minutes and 60 minutes is rarely more than .05. Typically it will drop slightly, but never very much. I have never seen the pH rise during the mash, but the overall pH will come up .1-.2 during the sparge (even with RO water), basically I'm measuring the pH of the preboil wort. To prevent this rise I will acidify the sparge liquor slightly. If I want a rise in pH, I will not add any acid.

The other thing I have noticed during the boil is a slight rise in pH, sometime as much as .1. I usually adjust the pre-boil pH with phosphoric acid. I the past I have adjusted it with lactic acid and had a slight drop in pH. I have never been able to find out why this happens or why there is a difference between the two acids. It's not a big deal, I just compensate for either acid when I use them.

 

[DuncB]

@mabrungard
Thanks for the advice, I'll check at 45 minutes from now on.
Probably won't adjust at all as the calculations always seem close to my measurements in the past.