pH stability of wort

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BuzzCraft

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not sure if this qualifies as "brew science", but thought i'd post here first. does any one know how long pH will remain stable in a wort sample?

i have access to accurate pH meters at work and was wondering whether i can collect samples of wort during various stages of the mash/sparge process and check them the next day.

any information related to this would be appreciated (i.e. need to bring samples up to enzyme denaturing temp before storing?....wouldn't think this would affect things. freeze or refrigerate samples?, etc)


thanks.
 
pH will vary with temperature, dissolved CO2, and ongoing chemical reactions (especially metabolism of any bugs). I'd freeze the samples to slow any chemical reactions, enzymatic activity, and any yeast/bacteria that get in it. But cooling will change pH a little and allow more dissolved CO2. Ultimately it depends on how buffered your water it. High hardness will be more resistant to pH change - both during mash and during storage/transport to pH meter.
 
The information is not very valuable the next day, as you can't respond to it (until the next brew day but that is a very slow feedback process).

I would recommend a pH meter at home as a good investment. A field quality meter at home is more useful for mash pH than a lab quality meter 2 days later.

However, if I had access to a lab quality meter every day at work I would certainly use it to measure finished beer pH, probably on all of my beers (something I don't do now unless I suspect a problem).

ETA: I could guess at some factors that would affect pH stability, but not the magnitude of effect.

If I were you, I would mash a few ounces of grain in a travel coffee mug or something at work some day. Then you can get a pH reading during mashing and store samples for a couple days in a couple different ways and see empirically if any or all storage methods result in a stable pH.
 
Thanks for both of your replies and the information you've provided. Sounds like some testing is in order.

Based on previous tests with a borrowed meter at home, I think I'm pretty close on my mash pH. Although you're correct that I can't respond directly, I'm just hoping to get ball parks for different beer colors that I brew. If I know that I can adjust to proper pH for a beer of "X" SRM using "X" amounts of various salts, I won't bother checking pH in the future. I would think that I could come up with 4-6 buffering protocols that would cover the range of styles/colors I brew (fyi, I have very soft water here) and employ them in my brewing. Perhaps there is fallacy in that approach?
 
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