Right amount of phosphoric acid?

[berndawg84]

So I'm just getting into water chemistry, so forgive my ignorance. I don't have an accurate water report (working on it), but want to start with adjusting mash pH first.

I used Bru'N Water to look at this. I'm doing BIAB. With an initial mash water pH of 8.0, my estimated mash pH is 5.71 for my grain bill:

Fermentables

Amount Fermentable PPG °L Bill %
10 lb Belgian - Pilsner 37 1.6 81.6%
1 lb German - Vienna 37 4 8.2%
1 lb Belgian - Wheat 38 1.8 8.2%
0.25 lb American - Carapils (Dextrine Malt) 33 1.8 2%
12.25 lb Total



I'm shooting for a mash pH of 5.3, so Bru'N Water says that if I have

10% phosphoric acid, I should add 0.3ml of the PA to get to 5.3pH. My total water volume for the BIAB 5.5gallon batch is 7.3 gallons of water.

I just want to make sure I'm using the calculator correctly. Does this sound right to people? It doesn't seem like a lot of phosphoric acid compared to what I've seen listed in other threads. Thanks much.

 

[IslandLizard]

Without knowing your water's mineral composition, its pH means very little. Call your water company and ask to talk to someone in charge of water analysis. They have those figures you're interested in.

Do you have any numbers, the most critical ones (Ca++, HCO3-)?

How have your beers been so far?

 

[day_trippr]

I don't see .3 ml of 10% acid dropping a five gallon mash by .4 pH...

 

[berndawg84]

Without knowing your water's mineral composition, its pH means very little. Call your water company and ask to talk to someone in charge of water analysis. They have those figures you're interested in.

Do you have any numbers, the most critical ones (Ca++, HCO3-)?

How have your beers been so far?

Oh hmmm...I didn't realize that that affected things as much. I live in Denver. So the guy from Homebrewacademy.com lives in Denver. He posted his water profile once. There is a Denver water report, but the numbers are in a range, not specific. The guy from homebrew academy has his water as follows:

•Sodium, NA – 17 ppm
•Potassium, K – 2 ppm
•Calcium, Ca – 31 ppm
•Magnesium, Mg – 7 ppm
•Total Hardness, CaCO3 – 107 ppm
•Nitrate, NO3-N – 0.2 ppm
•Sulfate, SO4-S – 17 ppm
•Chloride, Cl – 21 ppm
•Carbonate, CO3 – 6 ppm
•Bicarbonate, HCO3 – 66 ppm
•Total Alkalinity, CACO3 – 64 ppm


I did also just message 2 breweries that are a couple blocks from me to ask them for a water profile. One brewery said they may have their water report, but doubt they could find it. He said he only uses a coarse water filter, doesn't do any other water chemistry adjustments. Interesting. Hopefully the other one gets back to me...

So using the above numbers, I used Bru'N Water again and got that I need 30.5ml of 10% phosphoric acid to lower my mash Ph from 5.84 (this is a new estimate based on the above numbers) to 5.3. That probably sounds more accurate.

Also...I know I could pay Ward Labs for my water report, but I'm trying to be frugal right now and spend my money on other brewing stuff I know it may not be best practice but..

 

[Hopsimus]

The Denver water report is available online at http://www.denverwater.org/WaterQuality/QualityReports/

You'll want the 'Treated Water Quality Reports' tab.

The most recent one posted is from 2015, so a couple years out of date now, but I would think it is fairly close to current numbers.

They also give a number to call to request a copy, but I haven't tried that myself.

 

[Weezy]

If you don't have a pH meter, be conservative. If you do have apH meter, I'd recommend putting in half of what the spreadsheet says you need, check the pH, then go from there. Use a dropper or pipete to add the acid.

 

[berndawg84]

Thanks. I found the water report here

http://www.denverwater.org/docs/ass...5691FE036EA/TreatedWaterSummaryReport2015.pdf

There are other average numbers I found via their site but it's a broad range. The tricky part with that water report is that Denver uses 3 different water sources and they seem to randomly change throughout the year. So taking an average seems to be the only way. Or, testing your water weekly or something.

Wheezy, I do have a basic ph meter. Eventually I want to get a fancier one. But that's a good idea, I will add half the recommended amount and then go from there.

But it does seem important. Jon palmer gave the example of a brewery he went to whose Stout tasted slightly acidic to him. He asked to see their mash ph and it was at 4.9. Since that brewery adjusted their water their stout has gotten much better. Pretty cool stuff.

 

[ajdelange]

The other alternative that many are adopting these days is the use of RO water. RO removes the minerals and in so doing also removes the variability in their concentrations.