Mash PH, how low is too low?

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zach1288

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I miss calculated my acid addition and the mash PH was at 5.02, by the end of the rest it was 5.12. Is this too low? I usually shoot for 5.1-5.3 on my pale beers. So i'm not far off but I'm a little concerned.
 

Homercidal

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I wouldn't worry. I *believe* pH is mainly important for speed and efficiency in conversion. Meaning, if you are close, it will still happen, but might take a lot longer.

For instance, this Sunday I measured water, added minerals, crushed grain, mashed in, calibrated my pH meter, and took a reading.

4.74

Of course I was concerned, but not for the mash itself. I was concerned because there was "No Friggin WAY!" my pH could have been off that much! There was no way my mineral additions could have been off. No way my water was that far off it's normal.

Then it hit me: I used 100% RO water. Now this is what I normally do, because my water is high in alkalinity. But in this case I was brewing a dark beer, so I calculated my additions with 50% dilution and forgot when I measured water.

There was no easy way for me to increase the pH that I new of, so I unloaded the uhaul trailer I rented and drove it back to the store in a nearby town, stopped at the store to get a few things (but not the cocoa powder I needed for my boil...) and got back to the mash about 1.5 hours after mashing in. I collected my runnings and found I was off by about .03 from my calculations, which is pretty normal.

So I think hitting the pH is admirable, and certainly something to strive for, if you just get in the ballpark you will still make beer.

In my case, I sparged with 100% tap water to get the finished pH in range or close to it. It would have been better to have the flavor additions where I wanted them, but it's not the end of the world.
 

Manzier

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I think having proper pH is important as it effects the activity of the amylase enzymes. A amylase works best at pH 7. B amylase works best at pH 5. So it's a compromise to aim for around 5.4 from empirical evidence. I think there is more to it then just the speed of conversion, such as dextrin production and the like from pectins. But I'm not really sure. At a pH of 5.4 I always achieve good beer.


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afr0byte

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A lower or higher pH will change the hop utilization / quality of the bitterness, since the mash pH effects the boil pH....among other flavor differences
 

riderkb

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http://braukaiser.com/wiki/index.php?title=File:PH_and_temp_enzyme_matrix.jpg

This chart is very well made. It shows the pH and temp ranges for all of your enzymes.

From experience I can tell you that you can get full conversion in well under an hour even below pH 5.0. As long as the starch converts I would not sweat it.

On the other hand, I wonder how pH affects the sugar profile. If you held the mash temp constant and did a low pH vs high pH comparison, which one would make the drier (or sweeter) beer? Assuming you mashed long enough to get full conversion in each case, of course.
 

frettfreak

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Palmer States in "how to brew" that pH is important, but temp is way more important. As long as your in the ballpark you should be good. I brewed an imperial brown the other day and mashed at 5.1. Not ideal but got pretty close to my numbers. Still tastes good already so I am not worried.
 

Homercidal

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A little bit of baking soda will raise pH. Powerful stuff.

Props on the Judas Priest siggy, Homer!
Thanks! And thanks on the baking soda tip. I was sure there was something useful for raising the pH, but I thought it was some fairly exotic chemical I didn't have. By the time I got to looking it up, the brew day was done, and I was smacking my head for not bothering to look it up right away.

This reminds me to go check the fermentor to see how the beer is coming. I haven't even opened the door to the chamber since I pitched the yeast.
 

LarMoeCur

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I had a pH meter go wonky on me once. I added 18ml of acid instead of 6. I know! That's a lot and believe me you can taste it for sure. First batch of beer I had to toss in a very long time.

I'd check your finished beer pH. Depending on the style of beer anything in the 3 pH range will taste very acidic. Your beer probably finished 4.3-4.4. I think you will be alright again depending on the style of beer. Hopefully it's not a an IPA. The acid will dull any hop flavors so IPA will not have that good hop flavor. More like a dull muddy old hop flavor.
 

mabrungard

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This is an ancient thread, but it’s worth mentioning that pH also proteolytic enzymes. An overly low pH increases proteolysis and that can reduce body and mouthfeel. Its best to keep mash pH above 5.2 in most brewing.
 

NSMikeD

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In another thread there was a post with which I fully agree, that is to trust the pH software calculators more than your pH meter and use the pH meter to expose major issues. Zach1288 just shared a good example of this. Inexpensive pH meters in the hobby are not reliable and more likelihood an off pH meter reading would be due to either user error or meter error. But the big difference sufficient to alarm him to recheck his process, identify an input error that resulted in an incorrect process.

thanks for sharing.
 
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