Water Chemistry

[brewmeister13]

I'm starting to learn about water chemistry and want to make sure I am understanding correctly. From what I gather the most important aspect of water chemistry is getting the correct PH for mashing and sparging. I gathered that RA and grist help predict PH, but that RA in itself isn't something to worry about if you can get the correct PH. The next most important thing it seemed to me was the cl:so4 ratio. Other than that it seems that ion content is a matter of taste and beer style. Am I on the right track?

 

[ajdelange]

More or less, yes. Getting mash pH in the right band is a sine qua non. If you blow that part of the brew day you will not get a good beer (drinkable perhaps but not good). RA is a means for comparing brewing water and one can indeed draw broad conclusions about what various combinations of grain and RA will do in terms of mash pH.

You should not think of the chloride to sulfate ratio as a design parameter. Each of chloride and sulfate has its own effects. They are not antipodal (or log-antipodal as they would have to be if the ratio thing were valid). What this means in English is that if you over dose the gypsum (or your water is gypseous) you cannot 'repair' it by adding more chloride until the ratio is in line. A beer brewed with water containing 10 mg chloride and 10 mg sulfate per liter will be nothing like one brewed with 300 mg/L of each.

 

[brewmeister13]

Okay, good to know about the so4:cl ratio. From bru'n water it said that greater than 2 is very bitter, 2 is bitter, 1.3 is balanced, .75 is malty and .5 is very malty. Is this a general guide kind of like RA? What I mean by this is that since chloride accentuates sweetness and sulfate accentuates bitterness, if they are used in the recommended range (I saw sulfate as 0-150 if not highly hopped and up to 350 if highly hopped [another source says above 500ppm it is strongly bitter] and chloride as 10-100 unless sulfate is over 100, then limit it to under 50 [the other source says 1-100 unless og is 1.050 or above and then you can go as high as 350]) does this loose guide of values hold any truth?

 

[mabrungard]

Do visit the Water Knowledge page on the Bru'n Water site to learn more about the sulfate/chloride ratio. Most importantly, the ratio's usefullness is restricted to a narrow range of concentrations. At low concentrations, there isn't enough to taste. At high concentrations, they are overwhelming.

 

[ajdelange]

To my way of thinking bitterness is controlled by the amount, type and schedule of hopping. Sulfate has an influence on the perception of the bitterness tending to render it more assertive, dry and harsh to the point that where one has paid premium for noble hops he wants to avoid sulfate altogether. As I brew mostly beers that use noble hops my sulfate to chloride ratio is as close to 0 as I can get it. Nevertheless I can brew very bitter beers just by using more hops and beers in which the maltiness is louder than the bitterness by using fewer hops or later additions. But maltiness and hoppiness are different 'principal components' of taste. They don't offset one another though I suppose you could argue that one can tolerate more bitterness if the beer is very sweet and that a sweet beer would be mawkish if you didn't increase the hops.

Chloride and sulfate concentrations represent two degrees of freedom. Chloride concentration and a ratio or sulfate concentration and a ratio also represent those same two degrees of freedom. If it is more convenient for you to think in terms of a ratio then you should do so but I wouldn't take the 'this beer should have a chloride to sulfate ratio of x:y' admonitions too seriously.

You can get an idea as to what these two ions do to beer by adding gypsum and calcium chloride to finished beer. The tastes won't be exactly what you will get by adding these salts to brewing water but are close enough that you can use finished beer tasting results to guide you in your next brew.

 

[brewmeister13]

To my way of thinking bitterness is controlled by the amount, type and schedule of hopping. Sulfate has an influence on the perception of the bitterness tending to render it more assertive, dry and harsh to the point that where one has paid premium for noble hops he wants to avoid sulfate altogether. As I brew mostly beers that use noble hops my sulfate to chloride ratio is as close to 0 as I can get it. Nevertheless I can brew very bitter beers just by using more hops and beers in which the maltiness is louder than the bitterness by using fewer hops or later additions. But maltiness and hoppiness are different 'principal components' of taste. They don't offset one another though I suppose you could argue that one can tolerate more bitterness if the beer is very sweet and that a sweet beer would be mawkish if you didn't increase the hops.

Chloride and sulfate concentrations represent two degrees of freedom. Chloride concentration and a ratio or sulfate concentration and a ratio also represent those same two degrees of freedom. If it is more convenient for you to think in terms of a ratio then you should do so but I wouldn't take the 'this beer should have a chloride to sulfate ratio of x:y' admonitions too seriously.

You can get an idea as to what these two ions do to beer by adding gypsum and calcium chloride to finished beer. The tastes won't be exactly what you will get by adding these salts to brewing water but are close enough that you can use finished beer tasting results to guide you in your next brew.

Thank you, this helps me out a bunch. I am trying to brew a pale ale for my non hop loving friends that they may enjoy (and if not I'll still drink it). I was trying to keep the harsh perception of hops to a minimum. I may just try to keep both Chloride and Sulfate to a minimum while hitting my target PH. Thanks again for this great info AJ and I'll definitely try the gypsum and calcium chloride after brewing to see how it changes my perception of the brew.

 

[Bassman2003]

AJ, thanks for the tip about adding the minerals to finished beer to see their impact. I will be trying this as I use calcium chloride in a lot of my beers but never added much gypsum. I might like the flavor or find I like different amounts of what I do add without putting a batch in the "experimental" category.