Pre-boiled water adjustments

[SteveH]

Hi all,

Given the current state of lockdown I'm experimenting with pre-boiling as a way to reduce the alkalinity of my high-alkalinity (around 260ppm) water.

Yesterday I boiled about 16l for 30mins with quarter of a campden tablet and half a teaspoon of gypsum, and measuring today with a Salifert KH kit indicates it's now around 40ppm.

My question is what will this process have done to the sulphate/chloride and calcium?

I've got a Ca kit so can test that, but I'm getting a bit lost with what other additions I should now add (planned recipe is a Saison with only pilsner, vienna and wheat malt) - does the boiling change the sulphate/chloride or just reduce the alkalinity? Will the gypsum added pre-boil impact the sulphate of the post-boil water?

I do also have 15l of Ashbeck left which I'm planning to mix with the pre-boiled water and hopefully end up with something suitable for a very light/dry Saison.
Any help or pointers to info would be much appreciated to help me figure this out!

 

[foxy]

Hi all,

Given the current state of lockdown I'm experimenting with pre-boiling as a way to reduce the alkalinity of my high-alkalinity (around 260ppm) water.

Yesterday I boiled about 16l for 30mins with quarter of a campden tablet and half a teaspoon of gypsum, and measuring today with a Salifert KH kit indicates it's now around 40ppm.

My question is what will this process have done to the sulphate/chloride and calcium?

I've got a Ca kit so can test that, but I'm getting a bit lost with what other additions I should now add (planned recipe is a Saison with only pilsner, vienna and wheat malt) - does the boiling change the sulphate/chloride or just reduce the alkalinity? Will the gypsum added pre-boil impact the sulphate of the post-boil water?

I do also have 15l of Ashbeck left which I'm planning to mix with the pre-boiled water and hopefully end up with something suitable for a very light/dry Saison.
Any help or pointers to info would be much appreciated to help me figure this out!

This article here could help you.
https://www.morebeer.com/articles/waterhardness

 

[Ghillie]

Hi all,

Given the current state of lockdown I'm experimenting with pre-boiling as a way to reduce the alkalinity of my high-alkalinity (around 260ppm) water.

Yesterday I boiled about 16l for 30mins with quarter of a campden tablet and half a teaspoon of gypsum, and measuring today with a Salifert KH kit indicates it's now around 40ppm.

My question is what will this process have done to the sulphate/chloride and calcium?

I've got a Ca kit so can test that, but I'm getting a bit lost with what other additions I should now add (planned recipe is a Saison with only pilsner, vienna and wheat malt) - does the boiling change the sulphate/chloride or just reduce the alkalinity? Will the gypsum added pre-boil impact the sulphate of the post-boil water?

I do also have 15l of Ashbeck left which I'm planning to mix with the pre-boiled water and hopefully end up with something suitable for a very light/dry Saison.
Any help or pointers to info would be much appreciated to help me figure this out!

This is a pretty tough question and open to a lot of debate...

Regarding your SO4/Cl values and ratio, I would have though that would be a multiple of your volume difference. i.e. for each: new ppm value = [(original ppm x (pre-boil/post boil)]? Solids can't evaporate, so you've just concentrated the ppm relative to the volume of water?

Might be the same for Ca, maybe you could run a before and after Ca ppm test and then try the calculation to confirm or disprove? If it adds up, you could assume the same for Cl and SO4?

 

[strange-steve]

Boiling will reduce both calcium and alkalinity as calcium carbonate precipitates out of solution. Did you decant the water after boiling into another container, because otherwise the chalk can dissolve back into solution as CO2 is reabsorbed?

Regarding your other questions, the sulphate:chloride ratio will stay the same, however the actual concentration of both will increase as Ghillie says due to evaporation of the water.

The gypsum added pre-boil will indeed increase the sulphate level as well as the calcium level.

 

[SteveH]

Boiling will reduce both calcium and alkalinity as calcium carbonate precipitates out of solution. Did you decant the water after boiling into another container, because otherwise the chalk can dissolve back into solution as CO2 is reabsorbed?

I left it to cool overnight and haven't yet decanted, was planning to do so this later today before brewing, hopefully not too much chalk will have dissolved by then, I'll have to re-test the alkalinity I guess?

I tested the calcium with a Salifert Ca kit and get about 130ppm for plain tap water, and about 110ppm for the boiled water - I guess that makes sense if some calcium has precipitated out, but the evaporation and gypsum added some back?

 

[strange-steve]

I'll have to re-test the alkalinity I guess?

It would be interesting to see if there's any difference because I've never actually tried reducing alkalinity by boiling so this is all theoretical.

I guess that makes sense if some calcium has precipitated out, but the evaporation and gypsum added some back?

Sounds like it makes sense to me thumb

 

[nixhaz]

How did it end up @SteveH ? I've got insanely high alkalinity water here (296ppm!!) and high Ca too so am thinking of trying the same instead of bankrupting myself with AMS for each brew!

 

[SteveH]

How did it end up @SteveH ? I've got insanely high alkalinity water here (296ppm!!) and high Ca too so am thinking of trying the same instead of bankrupting myself with AMS for each brew!

It worked out well @nixhaz - I ended up using half boiled water and half ashbeck, measured Alkalinity was about 30ppm (my normal tap water is about 260ppm) so much more suitable for the style I was brewing. Mash Ph was a reasonable 5.4 so pretty happy overall!

 

[nixhaz]

Brilliant, thanks @SteveH