If you have soft water and are brewing a hop forward beer, you’ll want some Gypsum on hand. Gypsum (calcium sulfate) is used to add permanent hardness to your brewing water in the form of calcium ions, which will increase the hop perception in your beer. 

 

1 gram of Calcium Sulfate in 1 gallon of water changes the salt levels by 61.5 ppm calcium, 147.5 ppm sulfate and adds 153.5 ppm to the hardness.