Hydrometer Sample: Hot or cold?

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I take my reading...

  • from a hot sample and calculate the correction

  • from a cooled sample with the cold break on the bottom

  • from a cooled sample with the cold break mixed up

  • other


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ESPY

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For those who take pre-boil hydrometer readings, I'm curious how you do it.

For some reason I've never fully trusted the hydrometer correction calculations in ProMash. I have absolutely no reason not to, but still don't. Therefore, I've always waited for my hydrometer sample to cool before reading. But then there's usually some cold break that settles out and I've never really known if I should leave the stuff on the bottom or mix it up before I take a reading.
 
ESPY said:
For those who take pre-boil hydrometer readings, I'm curious how you do it.

For some reason I've never fully trusted the hydrometer correction calculations in ProMash. I have absolutely no reason not to, but still don't. Therefore, I've always waited for my hydrometer sample to cool before reading. But then there's usually some cold break that settles out and I've never really known if I should leave the stuff on the bottom or mix it up before I take a reading.


A few brews ago, I had the opportunity to take a sample at 150 degrees F and adjust with promash, and then measure again when the tube dropped to 60 degrees F. I found no difference between the final reading and Promash's adjustment, but even with the 90 degree difference in tempurature it's not a large adjustment.

My immediate thoughts on cold break would be, that since it is not solulable, whether it is mixed up or at the bottom it would simply displace the liquid and not alter the gravity reading.
 
Ahh I voted wrong. My preboil I take out of the wort just after sparging. I then let it cool to temp while the wort is heating up and then add it back to the boil. I don't trust correction algorithms beyond a few degrees for some reason. Call me paranoid, but I haven't seen the actual equation so maybe that is why I get nervous, but it seems to me the higher than say 90's corrections are not er uhm correct? I am speculating but that is how I proceed.
 
Pabst Blue Robot said:
A few brews ago, I had the opportunity to take a sample at 150 degrees F and adjust with promash, and then measure again when the tube dropped to 60 degrees F. I found no difference between the final reading and Promash's adjustment, but even with the 90 degree difference in tempurature it's not a large adjustment.

I have heard that taking readings in hot wort tends to break hydrometers. I haven't experienced this, but it seems plausible, since breathing wrong anywhere near them tends to break hydrometers.

I usually cool my post-sparge sample to 60 in an ice bath. I put the sample tube in a 1 gal thermos, then add ice around it and fill with water. It cools very quickly.
 
Pabst Blue Robot said:
A few brews ago, I had the opportunity to take a sample at 150 degrees F and adjust with promash, and then measure again when the tube dropped to 60 degrees F. I found no difference between the final reading and Promash's adjustment, but even with the 90 degree difference in tempurature it's not a large adjustment.

Yeah I use some calculator off the net, maybe that is why I don't trust it. I dunno, at any rate I have done comparisons and found them to be occasionally a point or two off...this could be reader error though.
 
cweston said:
I have heard that taking readings in hot wort tends to break hydrometers. I haven't experienced this, but it seems plausible, since breathing wrong anywhere near them tends to break hydrometers.

I usually cool my post-sparge sample to 60 in an ice bath. I put the sample tube in a 1 gal thermos, then add ice around it and fill with water. It cools very quickly.


It's funny, I've broken 4 hydrometers over the course of my time brewing but never from that. Boiling water might do it, but I've never had problems at mash temps. Now I'm in for a 5th, I can feel it...
 
zoebisch01 said:
Yeah I use some calculator off the net, maybe that is why I don't trust it. I dunno, at any rate I have done comparisons and found them to be occasionally a point or two off...this could be reader error though.

This may sound like a really stupid question, but is your graduated cylinder on a level surface? I used to take readings with mine on my workbench which isn't level, and it would throw the reading by about 2 points.
 
Right before turning the kettle off, I take a sample with a 1 cup pyrex cup and put it in the fridge. By the time I get the wort chilled, in the fermenter and get the big equipment cleaned, the sample is right at 60 and the break material has settled.
 
Pabst Blue Robot said:
This may sound like a really stupid question, but is your graduated cylinder on a level surface? I used to take readings with mine on my workbench which isn't level, and it would throw the reading by about 2 points.

Yeah, we made sure of that when we installed it hehe. Tbh, I really don't get it but at any rate if I could actually find the equation somewhere it would probably put my mind at ease. The funny thing is it seems hard to find charts that go beyond 100 or so (guessing at the actual numbers, every time I had searched for charts they were always ranged from something like the 40's to 100 or whatever) and I was wondering if they just didn't want to put those numbers up on the charts or if there is some other reason.
 
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