[cfleisher]

How much gypsum per gallon do I have to add to my mash/sparge water to lower my ph into the optimal range. My water is 7.5 ph.

[sambates]

Download Bru'n Water and you can calculate your grain bill, mash and sparge amounts and then adjust the gypsum to achieve your desires pH. I use it every batch and it's awesome. Just make sure you get an up-to-date water report to plug in.

[erockrph]

+1 to BrunWater. The calculator on Brewer's Friend is excellent as well (http://www.brewersfriend.com/mash-chemistry-and-brewing-water-calculator)

Basically, there's a lot more to it than simply making a generalization. Your grist and starting water profile are vitally important in order to determine what type of mineral and/or acid additions you need to hot your target mash pH.

[hopfenundmalz]

The pH of the water has little influence on the pH of the mash. You need to understand the buffering capacity of the water, which can be low or high at a given pH.

Certain grains will have higher acidity than others and how much are used, along with the hardness of the water (mainly Ca, and to a lesser extent Mg) combining with phytin from the malt, will lower the mash pH.

So it is not simple, and we can't answer the question as stated. Programs such as Brunwater will solve the problem for you, if you know the water report and the grist for the recipe.

[mabrungard]

Don't plan on relying on only calcium additions to get your mash pH where you want it. You could end up with a minerally taste. An appropriate addition of an acid is much more effective and is less likely to degrade the beer flavor. In addition, you still have to concern yourself with reducing alkalinity of your sparging water. If your tap water alkalinity is high, calcium additions are far less effective than acidification.

Acid: It's your friend! (OK, its dangerous and can bite you. Do learn to handle and use it properly!)

[denny]

How much gypsum per gallon do I have to add to my mash/sparge water to lower my ph into the optimal range. My water is 7.5 ph.

Who knows?  It depends on the composition of your water, not just the pH.  And just gypsum isn't a great way to adjust pH.  Using some acid would work better.

[Steve L]

I definitely like bru'n water. At first it seems a bit difficult to understand everything that it covers but you quickly learn the interplay of all adjustments and how they interact with all the phases of mashing and sparging. FWIW, I will take my water, which is high in bicarbonate, and I dilute it down with distilled to my target alkilinity, then I add either Gyrpsum or Calcium chloride depending on my recipe and goals to get my calcium, chloride and sulfate levels where I want them then I will acidify my mash water until I get it to the PH I'm targeting.  But as the others have eluded to, adding one thing often times affects something else and you end up changing and balancing your additions to dial in the target profile. for me this would be impossible without the spreadsheet. I'm kinda new to the whole water adjustment thing so I don't really know if this is the long way to get it done,  but it has worked for me so far.   hope this helps

[erockrph]

I definitely like bru'n water. At first it seems a bit difficult to understand everything that it covers but you quickly learn the interplay of all adjustments and how they interact with all the phases of mashing and sparging. FWIW, I will take my water, which is high in bicarbonate, and I dilute it down with distilled to my target alkilinity, then I add either Gyrpsum or Calcium chloride depending on my recipe and goals to get my calcium, chloride and sulfate levels where I want them then I will acidify my mash water until I get it to the PH I'm targeting.  But as the others have eluded to, adding one thing often times affects something else and you end up changing and balancing your additions to dial in the target profile. for me this would be impossible without the spreadsheet. I'm kinda new to the whole water adjustment thing so I don't really know if this is the long way to get it done,  but it has worked for me so far.   hope this helps

Right, the biggest part of the learning curve is figuring out the best set of steps to get to your target mineral and pH profile without having to go back and forth with a bazillion tweaks because every time you make a change it changes something else.

It sounds like you follow the same steps as I do; i.e., set your flavor ions first, then adjust pH. That almost always works out to be the easiest course of action. The Brewer's Friend calculator has a nice function where you can tell it what form and concentration of acid you're using, your target pH, and then it gives you the volume of acid to add. This way you really only need to tweak a couple of mineral additions once you have your water and grist inputted.