Treatment of brewing water

[dirtydingus]

Using RO water how much phosphoric acid takes the PH from 7.44 down to 5.5? There are post out there that say treat all brewing liquor to 5.5. Gordon Strong says that, among other reputable brewers. Do you leave the PH probe in the 5 gal RO jug until it stops? I think I added 1.5 ml to each 5 gal jug and the PH meter finally stopped at 4.6 after 45 minutes. I use the MW 101, and yes it was freshly calibrated. I'm lost when it comes to water chemistry. Maybe there are previous posts out there that will help. Thanx.

 

[tooldudetool]

I'm no water chemistry expert, but I can tell you the pH of your brewing water isn't really relevant, it's the pH of your mash that counts. RO water has very little buffering ability (ability to resist changes in pH). For example if your tap water has high alkalinity, it has a high buffering capability, because it's mineral content will offset attempts to change its pH. RO water has almost no mineral content, so it's pH can be very easily changed. It will actually change pH just from interacting with the air. I would suggest using a brewing water calculator or spreadsheet (I use Bru'n Water), to estimate your mash pH based on your water and grain bill. Like I said, I'm no expert, but this is the info I've gleaned from cruising the forums here. I'm sure AJ or Martin could chime in and explain it much better.

 

[Brewcycle69]

Couple of things,

There is a really good brewing water primer in the Brew Science section, great place to start.

The words "brewing water" also means "mash water"; the PH you referenced is for the mash water with the grains. You may want to check out a spreadsheet like Bru'n Water which provides a good estimation of your PH based on your tap water and the grains you're using. The mash PH will vary greatly between a pale ale and a stout. Bru'n Water also has some very good brewing water information.

Good Luck!

 

[brewing_clown]

If you're lost, the best first step is to get hold of a water report for your local supply. Ward labs has a test for home brewers. Once you get that back, and plug the numbers into Bru'n Water or any of the other tools out there, you'll have a better picture of what's going on.

It's important to remember that your grain bill has a big effect on mash pH so it will vary, as will any need for water chemistry additions, depending on what you are brewing.

The water chemistry primer is a great resource also.

 

[RM-MN]

Using RO water how much phosphoric acid takes the PH from 7.44 down to 5.5? There are post out there that say treat all brewing liquor to 5.5. Gordon Strong says that, among other reputable brewers. Do you leave the PH probe in the 5 gal RO jug until it stops? I think I added 1.5 ml to each 5 gal jug and the PH meter finally stopped at 4.6 after 45 minutes. I use the MW 101, and yes it was freshly calibrated. I'm lost when it comes to water chemistry. Maybe there are previous posts out there that will help. Thanx.

It isn't just the pH that matters with brewing with RO. Your mash water needs to have some mineral content that RO lacks so you use the addition of the correct amount of the right minerals to control the ph of the mash, not just adding acid to control it.