Water for a kolsch

I have an old water report from my supplier that puts my bicarb at 151, calcium at 28, and magnesium at 15 If I’m understanding Brunwater correctly, I need to just use distilled water in order to get my water profile in line for a light brew such as a kolsch, as these numbers are just too high. Am I right?

Thanks,

Ron

Unfortunately not. Your calcium is too low even before dilution, but your bicarb is too high. I would dilute with distilled by at least 50%, and then add some CaCl to bump the Ca level to >= 50 ppm, and bring the pH down to 5.5 or lower.

You can brew light beers with lower Ca levels, but my experience is that it takes them longer to clear.

[quote=“rebuiltcellars”]Unfortunately not. Your calcium is too low even before dilution, but your bicarb is too high. I would dilute with distilled by at least 50%, and then add some CaCl to bump the Ca level to >= 50 ppm, and bring the pH down to 5.5 or lower.

You can brew light beers with lower Ca levels, but my experience is that it takes them longer to clear.[/quote]

+1. Yep.

FWIW, I made a kolsch about 6 weeks ago and used the instructions in Bru’n Water for pre-boiling water to drop the bicarbonates in my water. I adjusted it with CaCl to get the calcium back to a recommended range without increasing pH. Used less gas than a trip to the store to get water. It’s still “lagering” but nicely clear. Looking forward to bottling it in a couple of weeks, but the hydro sample when I transferred it to secondary was nice.

Nah, that water isn’t that bad. Yes, the calcium is too low to promote the removal of oxalate in the mash and to promote adequate flocculation in the fermenter. But other than those needs, there is no need for calcium in brewing water.

For a kolsch, I do recommend a bit more calcium for the two reasons above. I wouldn’t take it higher than about 50 ppm Ca since this is a fairly delicate style. Personally, I like to boost both Cl and SO4 since the SO4 helps dry the finish. Just 0.15 gram/gal each of gypsum and CaCl will provide the Ca and the Cl and SO4 levels will be in the 20 ppm range…very modest.

The high bicarbonate content does have to be neutralized or the mash pH will be too high. About 1 ml per gallon of 88% lactic acid will take care of the bicarb. In the case of German beers, using lactic acid is a very important factor in promoting that ‘German’ flavor. At this dosing rate, the lactate ion should be below the taste threshold for most people. So don’t worry there.

Good starting point for brewing water. Don’t even think about dilution with distilled or RO.

Thanks a million, guys. It was the bicarb that was confusing me. I didn’t realize I could use the acid to neutralize it. Lots for me to learn.

Cheers,

Ron

You might also want to get a more recent water report.

Mine fluctuates quite a bit over the years.