how much acid to add?

[briggssteel]

I wanted to adjust my water before mashing and I'm planning on using lactic acid to drop it to 5.5 pre mash. What I can't find an answer for is how much I need to add roughly. Is there a basic ratio? something like 2ml per gallon will drop the PH by .1. I completely made that up but is there a guideline to how much I need to use? Thanks in advance.

 

[solbes]

I would suggest 2 things. 1) Buy a decent pH meter and 2) Download the free EZ Water Calculater (Excel spreadsheet) from this site. You will also need a copy of your water profile.

Your lactic addition will change based on your water profile (higher alkalinity will increase lactic) and grains used (darker grains will reduce lactic). The EZ calculator will get you close and the pH meter will allow you to fine tune.

 

[onthekeg]

Every water supply will have different requirements due to the buffering ability of the water. Your recipe will also adjust the pH due to the dark roasted malts that will lower the pH also.

 

[TopherM]

Most base malts will get your PH around 5.5-5.8 during the mash without having to add anything. 5.1-5.5 is considered ideal, so you will be pretty close to ideal without any additives, unless you have really weird local water.

 

[briggssteel]

Right. I should have been more specific. I'm planning on starting with RO water and I'm adding the specialty grains at the end of the mash so they don't drop my PH. At the start of the mash I'll be adding a teaspoon of calcium chloride. I'm trying the Gordon Strong method I mentioned in a previous post.

 

[wubears71]

You really need to get a good pH Meter. Lactic Acid is really strong. I have added as little as 0.1 mL to get my pH within Mashing range. I would not add lactic acid even with RO Water unless I have a pH Meter and then add it in extremely small increments.

 

[briggssteel]

Good to know it's that strong. I do have a quality PH meter I just bought and calibrated. I'm using a little over 8 gallons of water total for my next batch so maybe try 1 ml for all of it, take a reading and keep adding from there until I hit 5.5?

 

[wubears71]

Good to know it's that strong. I do have a quality PH meter I just bought and calibrated. I'm using a little over 8 gallons of water total for my next batch so maybe try 1 ml for all of it, take a reading and keep adding from there until I hit 5.5?

I typically add 0.5 mL to start if the pH is > 6 with about 7-9 gallons in the Mash. I then stir and take another reading and then adjust from there. The only time I add 1.0 mL right away is if my pH is above 6.5 pH.

 

[bigdongsr94]

I think bru n water has RO water on the spreadsheet. You can select it and add your grains to see what you will have. Then add acid accordingly. I would download the bru n water and see if you get a better understanding. Obviously the pH meter people are suggesting is important but i feel you will prob just brew before then. I just started making water adjustments and find my water in which i thought was very hard actuallly doesnt buffer much. So when the grains are added my pH drops within range. The problem i have is later with sparging. My sparge water needs adjusted and I did that with Brunwater. I think EZwater is considered better but I am just at step one of the building water process.

 

[Buna_Bere]

For every 0.1 pH reduction you want, make 1% of your grain bill acid malt. Acid malt is malt sprayed with lactic acid.
The 1% acid malt=0.1 pH drop is just an approximation. Definitely try EZ water.