Author Topic: URGENT: First Attempt at kettle sour possibly gone wrong  (Read 2125 times)

Offline makemorebeer

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URGENT: First Attempt at kettle sour possibly gone wrong
« on: July 18, 2019, 07:35:28 PM »
ok.  so i borrowed a PH meter that i was told was calibrated.  possibly my first mistake.  so i went ahead and mashed.  boiled for 10 minutes, chilled to 100 and pitched Lactobacillus (no starter)  I used Omega.  my initial PH was 5.9, 12 hours after pitch i took a reading and it was at 5.63, then 12 hours after that, just a little bit ago, i took another reading and it read 2.20.  the goal was 3.5. 

Question 1) is it possible the PH dropped that drastically.  the batch is ready to boil at 8.1 gal.  after taking my chiller out the temp went up.  form 100 to 110.  so i thought that was OK, i put a blanket on it and it's dropped to 90F in the past 24 hours. 

Question 2) if it's possible this is actually at 2.2 is the batch salvagable, and should i be boiling it now to stop the souring?

Question 3) it doesn't taste severly sour in my opinion.  like nothing compared to lemon juice.  so i'm not sure what to do. 

Any help would be greatly appreciated.

Offline dtapke

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Re: URGENT: First Attempt at kettle sour possibly gone wrong
« Reply #1 on: July 19, 2019, 07:35:35 AM »
That is almost certainly wrong.

I would re-calibrate the meter and re-test. making sure that you're storing the ph meter in an appropriate storage solution and rinsing between checks.

As an additional note, since you're borrowing a ph meter, I'm assuming you're a relatively new brewer.

Make sure you aren't using an aluminum pot, as you'll end up with an aluminum oxide flavored beer.

Lastly, Buy your own PH Meter ;) I find the Hanna Instruments HI98128 to be fantastic, but its a hair on the pricey side for a beginner brewer, although I'm a huge fan of "buy it once and never have to upgrade"

for a cheaper solution the Hanna inst HI98103 is only $30, I'd suggest buying the beer calibration bundle from them also which comes with a bunch of calibration fluids, storage solution, and cleaning solution.


"nice" meter: https://hannainst.com/hi98128-phep-ph-tester.html
"cheap" meter: https://hannainst.com/hi98103-checker-ph-tester.html
Calibration kit: https://hannainst.com/calibration-bundle-for-beer-bottles.html
« Last Edit: July 19, 2019, 07:39:16 AM by dtapke »
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Online Oginme

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Re: URGENT: First Attempt at kettle sour possibly gone wrong
« Reply #2 on: July 19, 2019, 08:15:18 AM »
I agree with dtapke on his points.

To further clarify your post, when you say you borrowed a pH meter that was calibrated, does that mean that you had the buffer solutions to confirm calibration or to recalibrate the pH meter or were you operating on the basis that the person you borrowed it from had calibrated it before you borrowed it?

Depending upon the quality of the pH meter, you need to check calibration or recalibrate it just before use.  Laboratory grade pH meters and probes are fairly stable and can go for a day or so without needing to recalibrate, but we still check for calibration before use.  Cheaper units for water testing or home use have varying degrees of drift and should be calibrated before each use. 

The next question is how you stored the pH meter between your initial use and the follow up readings.  If the probe was left dry, then you need to rehydrate the membrane for a while before taking a reading.  The membrane drying out also leads to calibration drift.

Also, when looking for a pH meter note that resolution does not mean accuracy.  The cheaper pH meter from Hanna that dtapke recommended above has a resolution of 0.1 pH units, but an accuracy of +/- 0.2 units.  So a pH reading of 5.4 with this meter could be an actual reading of 5.2 to 5.6.

Recycle your grains, feed them to a goat!

Offline makemorebeer

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Re: URGENT: First Attempt at kettle sour possibly gone wrong
« Reply #3 on: July 19, 2019, 08:34:20 AM »
So my first thought was damn i don't have a way to calibrate this thing.  I considered it a bit more and brought a sample to work where there is a lab just down the hall.  i had the techs there confirm with their equipment i'm actually between 3.0 and 3.5 as of this morning.  So yea.  sensors way outa whack.  BTW, kettles Stainless.

i'm not a new brewer, although i only switched to AG last year.  Beer always turned out good so i never bothered watching my PH.  I batch sparge.  naturally now that I've done it once i plan to do it continually, and I've been wondering about my water profile now as well.  funny the rabbit holes we go down.

Thanks for the advisement on instrumentation.  I've been looking at the $12 one's on amazon with alot of questions.  I plan to pickup a better one for myself.  I'm more of a buy the right tool vs. the cheap one.  been burnt on too many power tools to keep making that mistake.

Oginme, I borrowed the PH meter from my dad who also uses it for homebrewing.  he calibrated it Monday before handing it off to me.  it's a cheapo unit so yeah.  No solutions to calibrate either so i was out of luck there.  didn't know they needed such frequent calibration.  so i keep reading about storing them wet.  hows that work?  and what is the membrane referenced.  all i see is a white thing on the bottom and what looks like a lightbulb full of fluid.  Probably sounding dumb here, but I've got no experience with PH meters.

Online Oginme

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Re: URGENT: First Attempt at kettle sour possibly gone wrong
« Reply #4 on: July 19, 2019, 09:13:12 AM »

Oginme, I borrowed the PH meter from my dad who also uses it for homebrewing.  he calibrated it Monday before handing it off to me.  it's a cheapo unit so yeah.  No solutions to calibrate either so i was out of luck there.  didn't know they needed such frequent calibration.  so i keep reading about storing them wet.  hows that work?  and what is the membrane referenced.  all i see is a white thing on the bottom and what looks like a lightbulb full of fluid.  Probably sounding dumb here, but I've got no experience with PH meters.

Not at all dumb, if you haven't worked with pH meters much in the past (and even those people who have) it is not a surprise that the construction is not apparent.  At the bottom of that "light bulb" looking sensor is a thin area where ions can transfer charges to the fluid inside the bulb.  This thin area is the membrane and it can be difficult to see.

Generally, most pH probes need to be kept wetted and are stored in a AgCl solution.  Alternatively, storing it in pH 4 buffer, or less preferentially a pH 7 buffer will keep it wetted.  There are also 'dry' bulb probes which can handle being stored dry, but require a few minutes soaking in a pH 4 solution to rewet the bulb and membrane.  These dry bulb probes almost always need to be recalibrated before every use.

Recycle your grains, feed them to a goat!

Offline makemorebeer

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Re: URGENT: First Attempt at kettle sour possibly gone wrong
« Reply #5 on: July 19, 2019, 09:37:12 AM »
so it'd make sense then that the probe I've got here must be a dry bulb type as it'd otherwise probably say in the instructions to keep wet?  it does say to rinse in distilled water before use.  Thanks for the information.  i'm the type who likes to understand why something works instead of just accepting it.

Offline dtapke

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Re: URGENT: First Attempt at kettle sour possibly gone wrong
« Reply #6 on: July 19, 2019, 09:45:37 AM »
so it'd make sense then that the probe I've got here must be a dry bulb type as it'd otherwise probably say in the instructions to keep wet?  it does say to rinse in distilled water before use.  Thanks for the information.  i'm the type who likes to understand why something works instead of just accepting it.

Without knowing the meter, it's impossible to say, although I'm going to venture a guess its a "$12 meter from amazon" so the directions are likely lacking. Almost* ALL PH meters need to be stored in a proper fluid, so I'd say there's a 90% chance or better it should be stored in solution. Do not store in RO or DI water.

my .02 is to definitely get the better hanna meter I posted, and the calibration bundle. I use the bottles, they also have sachets that are one time use. I keep the bottles because I prefer it that way, many people prefer the sachets.

as far as water quality goes, Ward labs does a homebrew water analysis for pretty cheap. Or you can be super nerdy like me and invest 500 in an RO/DI unit and know that you're starting with water that is perfectly void of anything, then add the minerals you want.

Lastly, You're not dumb. 99% of the population has no clue how to store, use, calibrate or even what a PH meter is. Now it's just up to you to learn about them ;)
32g eHERMS
Drinking: Dopplebock, NEIPA, Pils
Primary: empty
Secondary/Lagering:
Next Brew: RIS

 

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