Water Chem Check

[QldKev]

I've recently moved, and have access to a brand new rainwater tank.

So time to update my recipes for the salt additions.

Recipe for 100L batch (BIAB)

100L strike water
12.0 kg Pale Malt BB
6.0 kg Munich II
0.5 kg Crystal

Using the rain water I assume all elements zero, and tested pH is 7.1 at 22c

I'm looking at the additions
25.0g Calcium Chloride
20.0g Gypsum
11.0g Epsom Salt

It's been a while since I've calculated additions, so for the color and wanting an emphasis on a slightly dry and bitter ale, do you think the additions look correct?


QldKev


edit: I should add BeerSmith2 gives me the following
49.6g Gypsum
0.8g Epsom Salt

But that would throw the Chloride / Sulfate ratio way out?

 

[RdeVjun]

Yep, at first glance that seems remarkably similar to my rainwater additions for the style.

 

[Steve@PMF82]

Looks good to me, although personal preference is less magnesium - i only add 0.05g/L of magnesium and make the rest of the sulfate up with the gypsum. I just found it gets a bit minerally for my taste.

I would not do what BS2 suggests, stick to original plan!

 

[QldKev]

Thanks for the check over. I was not 100% happy with the additions, as the RA is -87, which I would had preferred to be closer to zero for the color.

I should have mentioned I had already commenced the mash; which at half time I just checked the pH (allowed to cool to room temp, about 27) is 5.3

With the Magnesium I also like to keep it low, bit Palmer recommends 10-30ppm, so I went within the bottom of the range.

QldKev

 

[QldKev]

I had a chance last night to have a read, my alkalinity (HC03) is too low, hence the RA was to low.

Updated additions

Recipe for 100L batch (BIAB)

100L strike water
12.0 kg Pale Malt BB
6.0 kg Munich II
0.5 kg Crystal

Using the rain water I assume all elements zero, and tested pH is 7.1 at 22c

I'm looking at the additions
25.0g Calcium Chloride
25.0g Gypsum
11.0g Epsom Salt
12.0g Baking Soda
5.0g Chalk

This get the RA to -14, which is a lot better than the -87
And keeps a Chloride to Sulfate ratio of 0.66 which is great to help enhance the bitterness, being an APA is what I am after.

 

[Steve@PMF82]

I would be interested to know your mash PH with those additions?

My rainwater has a starting PH of around 8.5, so after adding my salts i usually add some acid to get the starting PH down to 6.5 for a similar grain bill to one you just posted, gets my mash into the correct range of 5.2 to 5.6.

Edit: I should add that my water does test alkaline for ph but has a very low to almost nothing buffering capacity, it takes an ants fart of phosphoric acid to drop a couple of points.

 

[QldKev]

I would be interested to know your mash PH with those additions?

My rainwater has a starting PH of around 8.5, so after adding my salts i usually add some acid to get the starting PH down to 6.5 for a similar grain bill to one you just posted, gets my mash into the correct range of 5.2 to 5.6.

Edit: I should add that my water does test alkaline for ph but has a very low to almost nothing buffering capacity, it takes an ants fart of phosphoric acid to drop a couple of points.

Using the original additions
Mash pH was 5.3 at room temp
So using the -0.35 rule, at mash temp it would have been 4.95.

It will be a few months before I brew this same beer. (although my house beer, a 100L lasts a while) and the next couple of brews are going to be completely different grain profiles.

I'm pretty confident now with the extra baking soda and chalk it should be within range.


I take it your rain water is from a cement tank to get that pH?

QldKev

 

[Steve@PMF82]

Using the original additions
Mash pH was 5.3 at room temp
So using the -0.35 rule, at mash temp it would have been 4.95.

It will be a few months before I brew this same beer. (although my house beer, a 100L lasts a while) and the next couple of brews are going to be completely different grain profiles.

I'm pretty confident now with the extra baking soda and chalk it should be within range.


I take it your rain water is from a cement tank to get that pH?

QldKev

Interesting

I have cement tanks but the water in there does not get used for the house, the house tanks are Poly.
My limited understanding of water chem is that my high PH would come from free carbonates generated by things like bird shit on the roof, bugs and microbes ect and being in a rural area with very little to no pollution there is less Co2 in the atmosphere on the way down for the rain to absorb which would leave me with a lower PH.