Calcium reactor

[Alphonso]

Hi everybody.

First post but I've been reading on here for awhile and just wanted to thank everyone for all the awesomeness. The collective knowledge of everybody here is a great resource.

Anywho,
first question; does anyone here mess around with calcium reactors (aquarists?), or know if a similar process would work to dissolve chalk into water to harden it? Possibly utilizing the CO2 from fermentation? Like with a closed pressure system?

 

[urbanmyth]

I think most people just use a teaspoon or so of gypsum to harden their water. I did this in the last brew I did, as I use RO water. Somebody with a little more experience might be able to explain better...

 

[michaeltrego]

does anyone here mess around with calcium reactors (aquarists?), or know if a similar process would work to dissolve chalk into water to harden it? Possibly utilizing the CO2 from fermentation? Like with a closed pressure system?

Kai has done some work in that area: Building brewing water with dissolved chalk

 

[ajdelange]

One should never harden water with chalk. Chalk is highly alkaline and will send mash pH much too high. One of the main reasons for hardening water is to try to lower mash pH. An addition of chalk to a mash with 1 unit of potential to decrease pH has 3.5 units of potential to increase pH.

Sometimes the object of hardening is to get the calcium level high enough that it aids decarbonation. Obviously, calcium carbonate would be a poor choice for that.

Sometimes the object of hardening is simply to increase the calcium level for yeast health etc. In those cases the chloride or sulfate are preferred because they do not increase pH as the use of chalk would.

So when does one use chalk? When the mash pH is too low and needs to be raised. Another application is when one wants to brew with authentic water. He may go to the trouble of simulating the water of some city of brewing reknown as closely as he can, including the bicarbonate. This is almost always a waste of time and effort as, at mash pH, most of the carbonate and bicarbonate have been converted to carbon dioxide which will escape the hot mash.

Those who want to add chalk to their water must dissolve it in acid. Any acid will do (for dissolving it) but nature uses carbonic acid for that job. Brewers who are willing to take the trouble will sparge water to which the chalk has been added with CO2 or will put the chalk in a soda bottle or Cornelius keg, pressurize with CO2 and shake thus causing the CO2 to dissolve in the water. The resultant carbonic acid then dissolves the chalk.

As soon as the water is depressurized it is super saturated WRT CO2 and the object is to mix it with the target water before enough CO2 has the opportunity to escape that the chalk starts to precipitate back out.

 

[mabrungard]

A calcium reactor would work just fine, but I'm not sure how you would assess the ending alkalinity of the finished water, except through testing. I'm not sure how expensive a reactor is, but a carbonator cap and a 2L soda bottle is pretty cheap. (this assumes you have a CO2 cylinder).

Unless the CO2 from the fermenter was recompressed and injected into the water, I'm not sure that you could dissolve much chalk as the OP wants.

As many brewers have found, brewing a darker beer with RO or distilled water or any other low alkalinity water can produce a mash pH lower than desirable. Having some alkalinity is an important component in brewing. Just don't add too much alkalinity since the impact on beer quality can be severe.

 

[ajdelange]

A calcium reactor would work just fine, but I'm not sure how you would assess the ending alkalinity of the finished water, except through testing.

While testing isn't that difficult with the wide availability of kits one of the advantages of the soda bottle/cornelius keg approach is that it's easy to calculate the alkalinity produced by an addition. It is simply

alk = [CaCO3]*( 1.0167 -0.39579*exp( -(pH - 4.7)/0.43063 ) )

where [CaCO3] is the milligrams chalk dissolved divided by the number of liters it is dissolved in plus the number of liters its added to and pH is the pH of the mix. For example, if I put 200 mg of chalk in a corny keg, with 4 liters of water, pressurize and dissolve and then add that to 16 liters of untreated water [CaCO3] = 200/(4 + 16) = 10 mg/L.