How/when to check PH and how to adjust?

[nreed]

Hi all,

I've just ordered a PH meter and some 88% lactic acid solution so I can dip my toes further into water chemistry. I've also got some gypsum and epsom salts which I started using a couple of brews ago but yet to taste. It may be helpful to detail my current process before asking my question:

• I draw my total water for the mash and two step sparge - 12.3l for a 7.5l batch size.
• I add a 1/4 campden tablet along with my gypsum/epsom salts as per BeerSmith recommendations (I assume I add this to the total water volume?!)
• I heat up c50% of my water for the mash so 6l, and do a two step sparge with the remainder following the 60 minute mash. This is usually warm water not mash temp as I don't have access to a

I'm pretty happy with this process, I do BIAB and efficiency was at c74% on my last brew so came in a few points above BeerSmith recommendation of 72%.

So, using the above process, when do I check the PH reading and add the acid? I've seen people doing this 10 mins into the mash but will my batch sparge process increase the PH again after adjustment?

Would it be better to add some of the acid based on BeerSmith recommendation into the total volume and then do a small adjustment if needed during the mash. This way I assume my trated sparge water will not bring the PH back up as much?

 

[Jag75]

Fwiw , I treat my mash water and my sparge water separately. I check the mash ph about 15-20 into the mash .

 

[marc1]

I've never used Beer Smith, so I don't know how it calculates things for you, but I use mash pH estimation software that separates mash and sparge additions for water mineralization profile and suggests amounts of acid to add to the mash to hit a target pH.
I suggest you measure your mash pH throughout for a few brews to see how it works in your hands and how closely your software estimates mash pH.
Generally it should change over time but settle towards a final value.
You don't modify the pH once the mash is started. Take notes and make adjustments on future brews.
You can also measure and adjust your kettle pH, which is different from mash pH.
Also, careful with Epsom salts, too much magnesium will have a negative effect on flavor