I'm not really an expert in water chemistry having done most of my AG brewing in Newcastle which is blessed with some of the finest water in the world; it's something that I have just started to pay attention to. Interestingly enough I'm not convinced that there is a marked improvement in my beer quality, but I am seeing a jump from around 80 to 84-85% BHY (Brew House Yield i.e. into fermenter yield). My reading of both professional and home brew literature leads me to think that Calcium is king. You want at least 50-100 ppm of Ca2+ in the mash water now this is where it starts to get interesting; the upper beneficial limit for Calcium is more about the amount of accompanying Anions (Chloride, Sulphate, Magnesium, Carbonate...) than it is about the Calcium. I think we can take it as a given that too many of the anions will not improve the beer.
In the mash, other than its role in pH Calcium is an important enzyme cofactor (I regularly use the exemplar "not the wheel, nor the axle, but the grease that makes it run smoothly"), high concentrations of Calcium also protect Alpha Amylase from heat degradation, so it keeps working longer, hotter and better. Resulting in higher yields, better attenuating and more stable beer.
The role the anions is much more controversial, the idea that Chloride will promote pallet fullness is supported in both professional and home brew literature, the role of Sulphate and Carbonate are much less clear.
In the kettle, Calcium also lowers pH, aids in protein coagulation, helps with the removal of Oxalate (main cause of beer stone) reduces colour formation; and just for fun it reduces hop utilisation - but it improves the quality of the bitterness.
I think it's important to make sure you have enough Calcium in both the mash and the kettle, if you are confident that there will be adequate Ca carried over with the sweet water, then adjusting the kettle pH with acid is I think the easiest (personally I use Lactic Acid). If you aren't sure then more Calcium won't hurt, just keep an eye on the Anion contributions.
Try looking up "Residual Alkalinity" it's sort of the unified theory of calcium addition
MHB
Just as an aside I've been experimenting with Calcium Lactate, all the calcium you want without apparently any of the issues more conventional salts bring into play, only downside being the cost; it's very expensive by conventional brewing salt standards.
Any thoughts on using Calcium Lactate would be appreciated.
Mark
In the mash, other than its role in pH Calcium is an important enzyme cofactor (I regularly use the exemplar "not the wheel, nor the axle, but the grease that makes it run smoothly"), high concentrations of Calcium also protect Alpha Amylase from heat degradation, so it keeps working longer, hotter and better. Resulting in higher yields, better attenuating and more stable beer.
The role the anions is much more controversial, the idea that Chloride will promote pallet fullness is supported in both professional and home brew literature, the role of Sulphate and Carbonate are much less clear.
In the kettle, Calcium also lowers pH, aids in protein coagulation, helps with the removal of Oxalate (main cause of beer stone) reduces colour formation; and just for fun it reduces hop utilisation - but it improves the quality of the bitterness.
I think it's important to make sure you have enough Calcium in both the mash and the kettle, if you are confident that there will be adequate Ca carried over with the sweet water, then adjusting the kettle pH with acid is I think the easiest (personally I use Lactic Acid). If you aren't sure then more Calcium won't hurt, just keep an eye on the Anion contributions.
Try looking up "Residual Alkalinity" it's sort of the unified theory of calcium addition
MHB
Just as an aside I've been experimenting with Calcium Lactate, all the calcium you want without apparently any of the issues more conventional salts bring into play, only downside being the cost; it's very expensive by conventional brewing salt standards.
Any thoughts on using Calcium Lactate would be appreciated.
Mark
