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Old 08-10-2013, 05:18 PM   #11
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Gameface, are you calibrating your meter and checking your mash sample cooled to room temp?

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Old 08-10-2013, 05:47 PM   #12
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Yeah, it was a lot. I also have my doubts that you can't taste it under 5% of the grist. I chewed on a couple grains and they have a very strong sour taste.
Yes, they do. The stuff is 1 - 2% lactic acid by weight. I think it's pretty tasty when chewed - the combination of the lactic acidity and the sweetness of the malt itself.

As to whether you can taste it or not: try the beer on your friends without phrasing your request for their opinions in terms like "Does it taste sour?" Suggestion is awfully powerful. A double blind triangle test is the only way to be sure if the sourness is perceptible to people in general.

Quotation from the horse's mouth:

Importantly, Acidulated Malt NEVER
imparts “sour,” acidic notes to the
finished beer, as long as its portion of
the grain remains below 10%!"

But keep in mind that this horse (Weyermann) sells acidulated malt.

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My last batch had a measured ph of 5.82 so to get it between 5.2 and 5.5 I needed quite a bit.
According to Weyermann's guidelines 5% should drop your mash pH by 0.5 so that is the amount you would need for a mash pH (without any) of 5.82. But 5.82 is suspiciously high. Your alkalinity is low and most grains don't have DI pH's as high as 5.82, in particular Maris Otter which tends to come in low at 5.6 or so.
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Old 08-10-2013, 08:56 PM   #13
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Gameface, are you calibrating your meter and checking your mash sample cooled to room temp?
My ph meter was calibrated just before I took my readings on the previous batch but I did not calibrate this time.

I cooled the wort for the sample but it was still in the upper 80s. My meter claims to correct for temp but I've read that shouldn't be trusted.

I agree that 5.8 seems really high when I've been brewing for years and haven't had any major issues with my mash and my beers have generally turned out well. I was surprised to see that number.
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Old 08-10-2013, 10:21 PM   #14
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My ph meter was calibrated just before I took my readings on the previous batch but I did not calibrate this time.
Until you have demonstrated to yourself that your pH meter is stable for long periods of time you should at least check calibration each brew day. It is usually required that the inexpensive meters that home brewers typically buy be calibrated more than once per day. More on checking and calibrating at http://www.homebrewtalk.com/f128/ph-...ration-302256/.

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I cooled the wort for the sample but it was still in the upper 80s. My meter claims to correct for temp but I've read that shouldn't be trusted.
There are two temperature related effects at play. One is that the electrode response to a particular pH changes as a function of temperature. I.e. the voltage from an electrode in pH 5 solution is higher at 80 ° than it is at 40 °. This is what the meter corrects for. If the meter has an 'isoelectric pH' other than 7 ATC will introduce an error. Modern electrodes are usually pretty good wrt to this but I have one that is not.

The other effect is that the actual pH changes with temperature. ATC does not compensate for this. It is best that all measurements and calibration be carried out at room temperature because of both these effects.


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I agree that 5.8 seems really high when I've been brewing for years and haven't had any major issues with my mash and my beers have generally turned out well. I was surprised to see that number.
I'd bet on cal drift.
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Old 08-10-2013, 11:24 PM   #15
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The 5.8 was immediately after cal. The meter is a HI-99151 and it says "Beer ph meter" on the front. But if my previous mash ph was 5.8 and I used 4.4% acidulated malt this time around then the numbers basically check out because this time my measure ph was 5.36. I'll calibrate before use on my next brew day, and I get that the numbers are suspicious. I'll be more prepared with an ice bath for my samples. I've had a pretty solid brew day routine and the ph testing is kind of an awkward fit at the moment. I'll get it worked out so it's a smoother operation.

Now the cal procedure is pretty simple. I go into cal mode and use the specified ph solution, then it beeps when it's done with that one and I put the probe in the next solution. When I have calibrated in the past the meter displays the correct ph for the solution once stable (before the beep), so to me that means that the cal was good going in. Is that not a correct assumption?

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Old 08-11-2013, 02:35 AM   #16
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The question is 'how long does the meter hold the cal?' Inexpensive meters don't hold it long. You need to do a cal, then check both buffers again after 10 min, 20 min, 30 min..... The meter should still read the correct pH for the buffers. If it does not then recalibration may be necessary even after only a few minutes. This can be a real pain even though the calibration procedure is simple. The alternative, should you find this to be necessary, is to buy a more expensive meter.

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Old 08-11-2013, 09:17 AM   #17
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The question is 'how long does the meter hold the cal?' Inexpensive meters don't hold it long. You need to do a cal, then check both buffers again after 10 min, 20 min, 30 min..... The meter should still read the correct pH for the buffers. If it does not then recalibration may be necessary even after only a few minutes. This can be a real pain even though the calibration procedure is simple. The alternative, should you find this to be necessary, is to buy a more expensive meter.
Right, it seems to hold cal really well. I'll test it more...

No problem just checking cal by taking a reading from the cal solution instead of going through the cal procedure, is it?
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Old 08-11-2013, 11:26 AM   #18
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The question is 'how long does the meter hold the cal?' Inexpensive meters don't hold it long. You need to do a cal, then check both buffers again after 10 min, 20 min, 30 min..... The meter should still read the correct pH for the buffers. If it does not then recalibration may be necessary even after only a few minutes. This can be a real pain even though the calibration procedure is simple. The alternative, should you find this to be necessary, is to buy a more expensive meter.
It looks like a $275-300 meter, so I'd hope it performed at least decently.
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Old 08-11-2013, 11:30 AM   #19
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Right, it seems to hold cal really well. I'll test it more...

No problem just checking cal by taking a reading from the cal solution instead of going through the cal procedure, is it?
That should work fine. You might also try some of the suggestions in the meter calibration sticky. For instance, are you rinsing with distilled water and then wicking off excess water before you take your actual reading (after having calibrated)?
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Old 08-11-2013, 12:08 PM   #20
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No problem just checking cal by taking a reading from the cal solution instead of going through the cal procedure, is it?
That is exactly what you want to do. Recalibration wipes out the previous cal. What you want to do is check to see how long that cal is valid.
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