Author Topic: Refractometer Question  (Read 377 times)

Offline ynotbrusum

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Re: Refractometer Question
« Reply #15 on: February 26, 2020, 07:24:35 PM »
I rarely care enough to use it, but I acquired a lab grade hydrometer for final gravity readings.  It only has a range of .995 to 1.020, if I recall correctly.  Most of the time the refractometer is sufficiently close for my homebrewing.  I find it interesting, however, how many people who are first tasting a homebrew want to know the ABV and total time from brewing to drinking, but little else about the process.
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Offline KellerBrauer

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Re: Refractometer Question
« Reply #16 on: February 27, 2020, 12:51:16 PM »
I can get a 4 oz. sample from boiling to 60F in 30-60 seconds and that's good enough for me. 

How do you do that?

Put a boiling sample in a metal cocktail shaker with the lid on.  Swirl it in a bowl of ice water  Never takes me more than 60 seconds.  It helps that the Brewing America hydrometer I use only needs 4 oz.

I have always taken a sample in my hydrometer tube, measured the SG with a hydrometer, then taken a temperature measurement.  I then take both measurements and use the calculation tool in BeerSmith to derive the reading.  Are you suggesting this is not accurate?  I’m wondering why you would need a 60° sample.
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Offline Bel Air Brewing

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Re: Refractometer Question
« Reply #17 on: February 27, 2020, 02:08:53 PM »
My instructions say to take the sample for calibration at room temp, 70 degrees.
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Offline Slowbrew

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Re: Refractometer Question
« Reply #18 on: February 27, 2020, 02:21:32 PM »
I can get a 4 oz. sample from boiling to 60F in 30-60 seconds and that's good enough for me. 

How do you do that?

Put a boiling sample in a metal cocktail shaker with the lid on.  Swirl it in a bowl of ice water  Never takes me more than 60 seconds.  It helps that the Brewing America hydrometer I use only needs 4 oz.

I have always taken a sample in my hydrometer tube, measured the SG with a hydrometer, then taken a temperature measurement.  I then take both measurements and use the calculation tool in BeerSmith to derive the reading.  Are you suggesting this is not accurate?  I’m wondering why you would need a 60° sample.

Homebrew hydrometers are typically calibrated at 60F.  So any deviation in the sample temp will introduce error.

It sounds like you are already accounting for differences from standard, so your process sounds fine to me.

The only thing you might want to verify is that your hydrometer is actually calibrated to the 60F standard.  It also doesn't hurt to check the calibration with a 60F pure water.  Those pieces of paper can shift in the glass tube sometimes.

Paul
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Offline denny

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Re: Refractometer Question
« Reply #19 on: February 27, 2020, 03:44:33 PM »
I can get a 4 oz. sample from boiling to 60F in 30-60 seconds and that's good enough for me. 

How do you do that?

Put a boiling sample in a metal cocktail shaker with the lid on.  Swirl it in a bowl of ice water  Never takes me more than 60 seconds.  It helps that the Brewing America hydrometer I use only needs 4 oz.

I have always taken a sample in my hydrometer tube, measured the SG with a hydrometer, then taken a temperature measurement.  I then take both measurements and use the calculation tool in BeerSmith to derive the reading.  Are you suggesting this is not accurate?  I’m wondering why you would need a 60° sample.

For one reason, because it's dangerous to use boiling wort with glass.  For another,the farther away you are from a hydrometers calibration temp, the less accurate the conversipn formula is.  I use a thermos hydrometer, which has a thermometer and correction table built into it.
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Offline Iliff Ave Brewhouse

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Re: Refractometer Question
« Reply #20 on: February 27, 2020, 07:21:52 PM »
I can get a 4 oz. sample from boiling to 60F in 30-60 seconds and that's good enough for me. 

How do you do that?

Put a boiling sample in a metal cocktail shaker with the lid on.  Swirl it in a bowl of ice water  Never takes me more than 60 seconds.  It helps that the Brewing America hydrometer I use only needs 4 oz.

I have always taken a sample in my hydrometer tube, measured the SG with a hydrometer, then taken a temperature measurement.  I then take both measurements and use the calculation tool in BeerSmith to derive the reading.  Are you suggesting this is not accurate?  I’m wondering why you would need a 60° sample.

I take a hydrometer sample while coming up to boil. My flask is plastic. I put it in the freezer and it normally cools to ~60F when the boil has reached 15 minutes in that way I don't have to rely on the adjustment calc. My process is close enough that I don't need a reading sooner because I'm rarely off a point or two.
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Offline KellerBrauer

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Re: Refractometer Question
« Reply #21 on: February 27, 2020, 07:37:28 PM »
I can get a 4 oz. sample from boiling to 60F in 30-60 seconds and that's good enough for me. 

How do you do that?

Put a boiling sample in a metal cocktail shaker with the lid on.  Swirl it in a bowl of ice water  Never takes me more than 60 seconds.  It helps that the Brewing America hydrometer I use only needs 4 oz.

I have always taken a sample in my hydrometer tube, measured the SG with a hydrometer, then taken a temperature measurement.  I then take both measurements and use the calculation tool in BeerSmith to derive the reading.  Are you suggesting this is not accurate?  I’m wondering why you would need a 60° sample.

Homebrew hydrometers are typically calibrated at 60F.  So any deviation in the sample temp will introduce error.

It sounds like you are already accounting for differences from standard, so your process sounds fine to me.

The only thing you might want to verify is that your hydrometer is actually calibrated to the 60F standard.  It also doesn't hurt to check the calibration with a 60F pure water.  Those pieces of paper can shift in the glass tube sometimes.

Paul

Thanks for this information.  Yes, my hydrometer is calibrated at 60F and I have verified it several times.  I use a plastic flask and distilled water for calibrating.
« Last Edit: February 27, 2020, 07:39:00 PM by KellerBrauer »
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Offline Bel Air Brewing

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Re: Refractometer Question
« Reply #22 on: February 28, 2020, 12:48:37 AM »
We are pleased to announce that our OG is 1.056.
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Offline Richard

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Re: Refractometer Question
« Reply #23 on: February 28, 2020, 12:54:33 AM »
Homebrew hydrometers are typically calibrated at 60F.  So any deviation in the sample temp will introduce error.
I have a hydrometer (https://www.morebeer.com/products/triple-scale-hydrometer.html) that is calibrated at 68 F. My wort and ale spend a lot more time closer to 68 than to 60, so I like this a lot. I agree with Denny that I don't trust the temperature corrections very much, so I prefer to get my samples as close as possible to the calibrated temperature.
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