Mash PH

[ajoye]

When I BIAB I start with the full amount of water I need which usually is 8 gallons. I am unsure how to use the beersmith mash PH tool in this regard. Would I just assume sparge vol and sparge water ph should be 8 gallons?

[Oginme]

If you are starting with your full volume in the mash, there is no sparge water so you can just ignore the sparge volume and pH.  Your mash infusion water should be set to your 8 gal in order for the pH tool to calculate with any reasonable accuracy.

[ajoye]

Makes sense so from this screen shot I would need 40 ml of Lactic Acid for 8 gallons?

https://drive.google.com/file/d/0B8DfyJB9f-7VbWdQRXMweHB5dFU/view?usp=sharing

I see most people will mash in then check the PH and then change it but some just change the mash water to around 5.30 and call it a day. I assume changing the mash is a better option?

[Oginme]

There are several thoughts to how to adjust the mash pH.  Since most of the enzyme activity happens within the first 15 to 20 minutes and it takes a good 10 minutes for the mash pH to stabilize, I plan on adding my mash salts, measuring and recording the pH, then making any needed adjustments in my next brew.  Note that in my experience, the mash pH will drop from 0.1 to 0.2 units from the beginning of the mash (10 minutes in) to the end of the mash (at 60 minutes).

Another word of caution, I found the pH adjustment with acids in BeerSmith to be off by quite a bit.  My recommendation is to add the acid slowly (about 10% of what is recommended by the program at a time) and stir in.  Once you get the to top of the acceptable pH range (5.6) stop and let it ride from there as it should fall during the rest of the mash.

[ajoye]

So, just doing a example it adjustment says to use 40 ml of lactic acid. What you say you have see that off by?

[Oginme]

Honestly, I am not sure.  I do know that when the pH calculation first came out, I compared the pH predictions between BeerSmith, Bru'n Water, and EZ Water Calculator using some older recipes and found them all fairly close, but never quite accurate.  Since I adjust mash pH using salts and not acids, I was mostly testing that aspect.  I can say, however, that the acid addition recommendations on BeerSmith were grossly higher than those recommended by either of the other programs.  The recommendations for acidulated malt, for instance, was 10x higher than what I had used to reach the same pH result. 

As with all new modeling programs, I always recommend heading into it slowly and feeling out the quality of the prediction without risking a total loss of overshooting until the software is proven accurate.

[ajoye]

Good to know. Thanks

[durrettd]

I've been adjusting my water for many years, primarily using Bru'n Water, and I've never seen a need for 40 ml of 88% lactic acid in eight gallons. I would guess water that required that much adjustment would be unfit for brewing and perhaps unsafe for drinking. It may be right, but that's far enough out of line that it demands investigation.   I strongly recommend that you download Bru'n Water (https://sites.google.com/site/brunwater/), read the instruction tab (twice) and recalculate your pH adjustment. Yes, it's a complex subject, but with a minimum of study you can make it work reliably.

[ajoye]

I've been adjusting my water for many years, primarily using Bru'n Water, and I've never seen a need for 40 ml of 88% lactic acid in eight gallons. I would guess water that required that much adjustment would be unfit for brewing and perhaps unsafe for drinking. It may be right, but that's far enough out of line that it demands investigation.   I strongly recommend that you download Bru'n Water (https://sites.google.com/site/brunwater/), read the instruction tab (twice) and recalculate your pH adjustment. Yes, it's a complex subject, but with a minimum of study you can make it work reliably.

In Beersmith I just used a base water profile for say Milwaukee, WI which was 7.5 and used measured mash ph = 7.0 and desired 5.30 and it at last claimed 40 ml of lactic acid. It as mentioned earlier that the tool in beersmith is not really on target.

[Kevin58]

I have separate mash profiles set up for BIAB. This video has some valuable tips on the subject.

https://youtu.be/VKiEjhxo2oo