Improving the Accuracy of Measurement

[SonomaBrewer]

Curious what others do to improve the accuracy of gravity and pH measurements during the mash. Because the initial wort is so murky, I'm not getting reliable measurements for either.

For gravity, I use a calibrated digital refractometer as I found it took too long to cool the wort down for a floating hydrometer measurement. For pH I use a handheld meter. Both measurements fluctuate a lot.

Do any of you filter the wort before taking measurements? I'm thinking coffee filter or something like that now.

 

[dmtaylor]

1) I don't check gravity during the mash. But I sometimes cool a sample and measure gravity toward the middle of the boil to adjust boil time if necessary so that I can be closer to hitting my OG target by the end of the boil -- sometimes I cut the boil short or extend it a little as needed, and/or add more water if I overshot.

2) I calibrate my cheap pH meter immediately prior to use. Then dunk it in the hot mash, then add 0.25 to adjust the mash temperature reading to room temperature. Ta-da. Yes the reading fluctuates a little bit. But I also don't think pH is as critical as people make it out to be. If it's within 0.10 of reality, I'm happy. Experience shows the 0.25 adjustment for temperature is just about perfect for most mashes.

People will either love or hate my responses above. I don't care. Cheers all.

 

[bracconiere]

Do any of you filter the wort before taking measurements? I'm thinking coffee filter or something like that now.

i kinda do a mini vorlauf into a graduated cylinder a few times to get clear wort.

 

[micraftbeer]

I use a fine mesh stainless steel strainer to pass the sample through into the measuring disc of my Milwaukee digital refractometer. I tried coffee filters but it was a pain and way too slow. I get repeatable results, even with wort from boil kettle that has a bunch of hops. I'll do 2 readings if they're identical, which happens 50% of the time, or I'll have to do a 3rd, with 2 out of 3 identical and the third different by 0.1 Brix.

Before I found the strainer, my results varied wildly.

 

[marc1]

Curious what others do to improve the accuracy of gravity and pH measurements during the mash. Because the initial wort is so murky, I'm not getting reliable measurements for either.

For gravity, I use a calibrated digital refractometer as I found it took too long to cool the wort down for a floating hydrometer measurement. For pH I use a handheld meter. Both measurements fluctuate a lot.

Do any of you filter the wort before taking measurements? I'm thinking coffee filter or something like that now.

So you're trying to measure the mash pH over time? I did that at first to see how it changed over time. Now I just measure once near the end. I calibrate my meter, pull a small sample, cool it, and run it. I mix with the probe when I first put it in to make sure I got air bubbles out, then let it sit for a minute and it stabilizes.

For a pre-boil gravity reading, I get some wort in a mason jar with a lid and stick it in a larger container of cool water. Some swirls, and within several minutes it's cool enough to test.

For me these readings aren't time-critical, I don't need them ASAP when I take them.

 

[micraftbeer]

Check the specs on your pH meter if you're sticking it directly in your mash. It's not about temperature compensation, most of the elements that do the measurement can't take the heat. The exception are probes that can tolerate mash temperature.

Knowingly damaging your probe of course defeats the purpose of trying to measure something precisely.

And all of the brewing literature references about pH are pH at room temperature. Which is not simply about temperature compensation, but the true pH is different at different temps.

 

[crazyjake19]

I've never really had an issue with either I pull a sample at 15 minutes into the mash and let it cool to take a pH reading, and a gravity reading (refractometer) out of curiosity.

For any pH readings - I have both an Apera PH60 and a $12 Amazon pH meter - always calibrate them right before your brew day for the most accurate readings. They're more finicky than something like a thermometer, and should be recalibrated more often.