Bigears - your water is like most supplying Dublin city - there is bugger all in it. In terms of alkalinity it is superb for brewing pale beer, but is deficient in calcium and sulphate. For stouts you will need to add carbonates to meet mash pH but on the whole its not bad. I always think it is far easier to add the required minerals than try to remove them.[/quote:2cwjw3gj]
Yes, I brewed an amber ale over the weekend and added calcium sulphate and calcium chloride to up the calcium levels to 150ppm. Mash PH worked out around 5.2 according to my ph strips so it doesn't seem to have gone completely pear shaped. My issue is going to be getting the porters and stouts right with such soft water. Chalk seems to be the main component in raising alkalinity but I've heard that it's not very soluble and can have limited success.
I queried the lack of a figure for magnesium in my water report and got the following reply:
[quote:2cwjw3gj]Total Hardness is the expression of the results of direct measurement (principally of calcium and magnesium) expressed as mg/l CaCO3.
Calcium Hardness is the expression of the results of the measurement of calcium only, as mg/l CaCO3.
Magnesium Hardness is the difference between total hardness and clacium hardness (all figures as mg/l CaCO3).[/quote:2cwjw3gj]
So if Total Hardness is 50 and Calcium Hardness is 40 to 45, this means that Magnesium is 5 to 10?
That seems about right. I wouldn't anticipate too much magnesium in the water anyway.
I wrote on my blog a while back...
[quote:1jjgi2mb]Hardness: This is essentially the concentration of calcium and magnesium in the water. It is divided into two further sets of terms:
Permanent hardness also called non-carbonate hardness. This cannot be removed from the water by simple means. It is made up from calcium and magnesium compounds such as calcium sulphate, magnesium sulphate, calcium chloride and magnesium chloride.
Temporary hardness also called carbonate hardness or alkalinity. This can be removed through the various treatments that brewers use, and is responsible for the lime-scale on household appliances. It is made up of calcium carbonate and calcium bicarbonate.
The significance of the distinction is seen when we consider what the two types of hardness bring to brewing. Carbonate hardness increases mash pH by neutralising the natural acids contributed by the mash, dragging the mash pH away and above the 5.4 that is optimal for malt amylases to work. Non carbonate hardness lowers mash pH and is beneficial to meeting the optimal mash pH.
The contrasting action of these differing forms of hardness leads us to another important term in brewing water chemistry: residual alkalinity. This is the net effect of the water hardness on the mash, and the extent to which the water will have to be treated to meet requirements. For most Irish water supplies carbonate hardness will out-weigh non carbonate hardness and the water will require a degree of treatment to lower the alkalinity.[/quote:1jjgi2mb]
Some of you might have read it already, but I think it explains the terms clearly enough.
This bit explains the 'equivalents' thing and why they refer to CaCO3 when talking about total hardness.
[quote:1jjgi2mb]Water reports state water hardness in 'equivalents' of calcium carbonate or bicarbonate. This is necessary in order to compare the different types of hardness in the water on a equal footing. When compared in this way it is seen that 3.5 equivalents of permanent calcium hardness or 7.5 equivalents of magnesium hardness is required to offset the pH raising effects of 1 equivalent of carbonate hardness. It is clear from these figures that carbonate hardness is very potent at increasing mash pH. If your water supply is low in carbonate hardness it might be possible to offset the residual alkalinity through the addition of calcium sulphate or calcium chloride, which is likely to be added at any rate in order to increase the calcium concentration to a more suitable level. However, if the carbonate hardness is very high, adding calcium to the water will not be sufficient to overcome the residual alkalinity and the carbonate hardness must be removed.[/quote:1jjgi2mb]
You have very high levels of alkalinity in your water - even more than mine - which means you will have difficulty brewing pale beer without treating the water. On the plus side you appear to have reasonable calcium, sulphate and chloride levels which should add some character. If you want to brew pale beer you'll have to get the alkalinity down to around 40 mg/l. You can do this with acids or carbonate reducing solution or use the magic pH 5.2 powder.