Please explain pH and Bru'n Water

[ClemTiger0408]

I understand pH and it's importance in brewing, I am more referring to how pH is calculated and used in the Bru'n Water file.

I had been using tap water and some RO and haven't been happy with results (and if Martin reads this he'll understand, I'm in Westfield, IN). So I've switched to all RO water and will build up.

I had tap water results from Ward entered into the spreadsheet. For my first brew with all RO, I simply made the dilution 100% on the Water Adjustment tab. I made all my additions adjustments and on brew day, I used lactic acid (88%) based on Bru'n Water but I WAYYYY overshot the acidity and my pH was in the low 4s despite adding the amount listed (I did add grain to mash acidification tab).

I then started tinkering with Bru'n Water spreadsheet. I zeroed out everything. No additions. No Malts. Just RO water (from the values listed for RO in the spreadsheet). With everything at zero, the spreadsheet says the estimated Mash pH is 5.79. When I tested the RO with my pH meter on brewday it was in the 6s (I have it written down but I'm at work currently). I found where the base stats for RO is in the Bru'n Water spreadsheet and noticed there is no where for RO water pH to be entered.

Is the spreadsheet somehow deriving pH using the properties of the water? I realize my RO may not be exactly the same as what's in the spreadsheet but why do I enter my pH for my tap water but not RO. I still haven't figured out how I missed the needed mash pH so much on my brew day, however.

 

[SnakeRidge]

I don't have a lot to add, so hopefully Martin or AJ will see this. I do know that the starting pH of your water is just about meaningless. Water on it's own has very little buffering capacity, so the grain will be the dominant driver of pH. I really just stopped by to say Go Tigers!!

 

[ClemTiger0408]

I was re-reading the Bru'n Water Instructions and came across this:

If only RO or Distilled Water is used for brewing, it may not be necessary to acidify the sparge water since RO and Distilled water already have low alkalinity. Acidification of sparge water is performed only to reduce the sparge water alkalinity to low levels. pH targets for acidification only serve as indicators of low alkalinity. Alkalinity reduction is the real goal of acidification. If the starting water alkalinity is less than about 25 ppm, then acidification should not be necessary.

So now I'm wondering if when I use all RO water, if I shouldn't bother using any lactic acid at all.

 

[SnakeRidge]

My water is pretty soft, and I don't acidify. I just add gypsum or CaCl2 to get to ~75ppm Ca+ and roll with it. I'm always in the 5.4-5.5 mash pH range.

 

[QuercusMax]

That seems to refer to acidification of *sparge* water, not acidification of water for the mash. I'm no water expert, but I think you may still need to acidify your strike water.

 

[mchrispen]

RO and distilled water have such low mineralization that using a pH meter with any accuracy can be difficult. Once you start nearing purity in water - the theoretical center point for pH is 6.0 at 25C.

With any water source, you should use acid or alkali to achieve the necessary estimated mash pH (usually between 5.2 and 5.6). With RO, you will use significantly less acid than someone with an average of 80 ppm Alkalinity as CaCo3 (as an example only). You will likely find that you will need to use more alkali (baking soda or pickling lime) than that same example if you are making a very dark beer. BW can help you determine all of that quickly. And you can confirm the estimates with a calibrated pH meter.

As with acidification of the sparge water - if you are using RO as the source, you should not need to acidify. A very tiny amount of acid would be required to titrate the sparging volume of RO to below 6.0 - there is little to no carbonate or bicarbonate to buffer the acid. I would not bother.

 

[Yooper]

I had tap water results from Ward entered into the spreadsheet. For my first brew with all RO, I simply made the dilution 100% on the Water Adjustment tab. I made all my additions adjustments and on brew day, I used lactic acid (88%) based on Bru'n Water but I WAYYYY overshot the acidity and my pH was in the low 4s despite adding the amount listed (I did add grain to mash acidification tab).

Is your pH meter properly calibrated? Unless you dumped a ton of acid into the mash, it would be impossible for your pH to be 'in the low 4s'.

How much lactic acid did you add?

 

[ClemTiger0408]

Now I sound like a super noob and I guess I'm using terms incorrectly. I BIAB so for me, the mash volume is the only volume I have.

Is your pH meter properly calibrated? Unless you dumped a ton of acid into the mash, it would be impossible for your pH to be 'in the low 4s'.

How much lactic acid did you add?

It was a brand new pH meter that I was using for the first time. I used the powders for the two calibration tests so the device was freshly calibrated (granted it's an inexpensive meter ~$25).

On a recent brew (Gumballhead clone), I added 3.8mL to 7.5 gallons of 100% RO water. The only grains were 2 Row and Wheat so they didn't drop the pH much. According to BW, this should have put me at 5.37. Maybe the low 4's is a stretch (I'm working off memory) but it was certainly somewhere in the 4s.

 

[Yooper]

Now I sound like a super noob and I guess I'm using terms incorrectly. I BIAB so for me, the mash volume is the only volume I have.



It was a brand new pH meter that I was using for the first time. I used the powders for the two calibration tests so the device was freshly calibrated (granted it's an inexpensive meter ~$25).

On a recent brew (Gumballhead clone), I added 3.8mL to 7.5 gallons of 100% RO water. The only grains were 2 Row and Wheat so they didn't drop the pH much. According to BW, this should have put me at 5.37. Maybe the low 4's is a stretch (I'm working off memory) but it was certainly somewhere in the 4s.

That's just not possible. Did you stick the meter back into the buffer, to see if it was still calibrated? You may have hit 5.3, but with 3.8 ml of lactic acid, there is no possible way to get under 5.2 let alone in the 4s.

 

[ajdelange]

On a recent brew (Gumballhead clone), I added 3.8mL to 7.5 gallons of 100% RO water. The only grains were 2 Row and Wheat so they didn't drop the pH much. According to BW, this should have put me at 5.37. Maybe the low 4's is a stretch (I'm working off memory) but it was certainly somewhere in the 4s.

I'm a little confused as to what the question is but if you add 4.8 mL of 88% lactic acid to 7.5 gallons of water with nothing else you should wind up with a pH of around 3.75. If you mash 20 lbs of Weyermanns pneumatic pilse with this (1.5 qts/lb) you might expect pH 5.56. If you mash 20 Lbs of Munton's Maris Otter you might expect pH 5.78. If you mash 20 Lbs of Crisp M.O. you might expect 5.63 (all at room temperature).

The reasons for adding acid are
1) Overcome the alkalinity of the bicarbonate in the water you are mashing with (0 or close to 0 with RO water)
2) Overcome the alkalinity of the base malt you are mashing. This can vary quite a bit so the pH with a fixed amount of acid will vary or the acid required for a particular pH will vary.

There are straightforward ways to compute acid requirements and mash pH. I don't know how Brun water does it but I believe it is based on empirical data.

 

[edroberts]

I understand pH and it's importance in brewing, I am more referring to how pH is calculated and used in the Bru'n Water file.

I had been using tap water and some RO and haven't been happy with results (and if Martin reads this he'll understand, I'm in Westfield, IN). So I've switched to all RO water and will build up.

I had tap water results from Ward entered into the spreadsheet. For my first brew with all RO, I simply made the dilution 100% on the Water Adjustment tab. I made all my additions adjustments and on brew day, I used lactic acid (88%) based on Bru'n Water but I WAYYYY overshot the acidity and my pH was in the low 4s despite adding the amount listed (I did add grain to mash acidification tab).

I then started tinkering with Bru'n Water spreadsheet. I zeroed out everything. No additions. No Malts. Just RO water (from the values listed for RO in the spreadsheet). With everything at zero, the spreadsheet says the estimated Mash pH is 5.79. When I tested the RO with my pH meter on brewday it was in the 6s (I have it written down but I'm at work currently). I found where the base stats for RO is in the Bru'n Water spreadsheet and noticed there is no where for RO water pH to be entered.

Is the spreadsheet somehow deriving pH using the properties of the water? I realize my RO may not be exactly the same as what's in the spreadsheet but why do I enter my pH for my tap water but not RO. I still haven't figured out how I missed the needed mash pH so much on my brew day, however.

I'm also in Westfield and I totally understand the battle with the liquid limestone we pour from the municipal tap.
I typically cut my mash volume with around 2 gallons of distilled water, then acidify from there (~1mL lactic per gallon). I'm not quite sure I have it all dialed in yet, but having the natural bicarbonate in there certainly beats re-adding to pure RO water.

 

[edroberts]

@clemtiger0408 BTW... I have a Ward labs report from September if it helps any.