Can pH of runnings ever exceed pH of Mash and Sparge Water

[303Dan]

Hello,

First post. Thanks in advance to anyone that can answer my question:

Assuming I am fly sparging (although I guess it applies to any type of sparging), is it possible for the pH of the runnings into the kettle to ever exceed the higher of the two values: Mash pH and sparge water pH?

In other words, from a practical sense, if I measured my mash pH to be, say, 5.3, and I adjusted my sparge water down to say, 5.5, is there any reason at all to monitor the pH and/or gravity of my runnings while fly sparging? (Assuming I understand correctly that a pH of under 6.0 or so prevents tannin extraction)

To this point, I have been taking periodic samples while sparging, cooling them to room temp and taking a gravity reading. I stop sparging when they get near 1.010. But I've also been adjusting my sparge water down to 5.5ish before I sparge. So am I wasting my time at that point monitoring the gravity of the runnings? Do I not have to worry about extracting tannins from the grains given my pH levels?

Thanks in Advance!
Dan

 

[ajdelange]

Assuming I am fly sparging (although I guess it applies to any type of sparging), is it possible for the pH of the runnings into the kettle to ever exceed the higher of the two values: Mash pH and sparge water pH?

No.

In other words, from a practical sense, if I measured my mash pH to be, say, 5.3, and I adjusted my sparge water down to say, 5.5, is there any reason at all to monitor the pH and/or gravity of my runnings while fly sparging?

No unless you want to learn how much sparging it takes to get down to the point where you are getting very little extract for each extra gallon run off.

 

[303Dan]

No.

No unless you want to learn how much sparging it takes to get down to the point where you are getting very little extract for each extra gallon run off.

Thank you! I'm glad I was thinking about it the right way.

Dan

 

[Colbizle]

Good question Dan, I was wondering this too.

 

[ajdelange]

While it doesn't work in quite the same way can you think of a way to mix 100 °F water with 50 °F water and get a mix temperature higher than 100 °F or less than 50 °F? Can you think of a way to mix 4 SRM beer with 15 SRM beer to get a mixture paler than 4 SRM or darker than 15 SRM? Or a sugar syrup of SG 1.020 with one of SG 1.040 and get a mixture with SG outside those limits?

 

[mchrispen]

So the only case I can think that pH would rise would be the liberal use of chalk (calcium carbonate), particularly when using the excess amounts to ensure a mash pH of 5.5 or 5.6 in a very dark beer. As the chalk slowly dissolves it will raise pH, but I suspect the rate of dissolution is so slow that the effect is more a weak buffer than a direct contribution of strong alkalinity. Just a thought - not something I have observed.

Of course, we don't use chalk for this very reason.