I gave in and bought a refractometer on amazon for $40. I decided to switch to a refractometer because I now do small batches (2-3 gal) and didn't want to waste a portion of the brew to take. Hydrometer reading. With that being said, I brewed today and used my new refractometer for the first time. My readings after my mash with the refractometer was at 1.042 with the promash conversion. I thought this was low so I used a hydrometer too and it came in at 1.046 which is right where it was supposed to be. I then did the boil and after boil my refractometer said only 1.048. This was way off as my post boil SG was supposed to be 1.054. I didn't compare this to my hydrometer bc I didn't feel like sanitizing it. After all that I guess does anyone know why my refractometer is reading so low and do others have his problem as well? Thanks in advance!!!
Yet another complaint thread about a malfuntioning refractometer!!!
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wyzazz
Well-Known Member
Did you calibrate it?
Did you calibrate it?
The only complaint threads I've come across about refractometers on here turn out to be operator error issues, like folks not calibrating them properly, trying to read already fermented beers with it where the alcohol content throws it off, stuff like that. I've not come actoss any complaint threads where there was actually something wrong with the refractometer, just the brewer using it wrong.
The only complaint threads I've come across about refractometers on here turn out to be operator error issues, like folks not calibrating them properly, trying to read already fermented beers with it where the alcohol content throws it off, stuff like that. I've not come actoss any complaint threads where there was actually something wrong with the refractometer, just the brewer using it wrong.
DakotaPrerunner
Well-Known Member
We are also working under the impression that your Ebay refractometer reads in brix. Some are designed to be used for antifreeze or salt water aquariums.
HItransplant
Well-Known Member
I dont have a refractometer, but Im not really sure how you can determine that your equipment isnt working. The fact that your reading doesnt match what the OG was "supposed to be," doesnt really tell you anything.
ClaudiusB
Well-Known Member
Before you can use a refractometer correctly two things need to be done, calibration and determine the Brix correction factor.
Determining the Brix correction factor is a one time deal and you enter the correction factor into ProMash system settings.
A Brix refractometer calibration is based on sucrose not wort (Maltose, etc.) and for this reason it is necessary to use a correction factor.
For more information take a look at ProMash calibration section.
Cheers,
ClaudiusB
Yes I calibrated it to water but did not calibrate it for the correction factor. I was thinking it wasn't workin properly bc it was four points lower than my hydrometer reading. Does debris in the sample cause the refractometer to read differently bc I noticed most of my drops of sample did have a little bit of debris in it. And yes this refractometer is supposed to be used on beer and not salinity or antifreeze.
Bentpirate
Well-Known Member
You want the sample debris free for a more accurate read.
What was temperature of your refractometer? If you were brewing outside and it got cold it could throw off the readings.
Does your refractometer have Automatic Temperature Compensation or ATC?
Keep in mind ATC corrects for the environment the refractometer is subjected to, not for the sample. The scale in the refractometer "floats" on a bi-metal wire, same principle as bi-metal thermometers. It is a narrow correction range however so I always leave my refractometer in the house in both hot and cold weather extremes of the current season. This information came from the Basic Brewing podcast dated Sept. 2, 2010 (visit www.basicbrewing.com to listen)
The hot wort sample is no more than 1/2 teaspoon or so and quickly cools on the refractometer lens. It should not be an issue.
Does your refractometer have Automatic Temperature Compensation or ATC?
Keep in mind ATC corrects for the environment the refractometer is subjected to, not for the sample. The scale in the refractometer "floats" on a bi-metal wire, same principle as bi-metal thermometers. It is a narrow correction range however so I always leave my refractometer in the house in both hot and cold weather extremes of the current season. This information came from the Basic Brewing podcast dated Sept. 2, 2010 (visit www.basicbrewing.com to listen)
The hot wort sample is no more than 1/2 teaspoon or so and quickly cools on the refractometer lens. It should not be an issue.
Water or Distilled water? My understanding has always been that you need to calibrate with distilled...I'm not sure how much of a difference it makes, BUT if you are off a couple points, and calibrate with water that reads a couple points different, then that could be your problem.
So what are you using to pull your drops? Did it come with a tiny pipette? I can't see how any particulates could into that little openning. I've never had particulate matter in any of my samples.
So what are you using to pull your drops? Did it come with a tiny pipette? I can't see how any particulates could into that little openning. I've never had particulate matter in any of my samples.
wyzazz
Well-Known Member
I've never gotten any particulate in any of my samples either, I take a spoonful during the boil and blow on it, then drop it on the refractometer. For samples during fermentaton I use the pipettes. No air bubbles, no particulate or it will change the reading.
Yes it was calibrated with regular tap water, but I don't understand how there is a difference between tap and distiller water because neither one should have any sugar in them. Yes my refractometer has an ATC. Also I used a pipette but when u put the few drops on the glass...you can see there were a few bits of particulate matter.... probably hop material. I'm still confused.
wyzazz
Well-Known Member
Your tap water may have minerals, etc in it that can throw off the reading.
wyzazz
Well-Known Member
I don't know the science behind it but mine says to calibrate with distilled water. And I do know that my tap water reads differently than distilled.
I've seen postings on here where the descrepincy between distilled and their tap water was 4-6 gav points....which is about what the OP's readings are off by.
What was it we were saying about operator error vs malfunctioning refractometers threads?
Well if thats the case this thread should be obsolete very soon! Ha I will try and recalibrate it tomorrow and see how that goes. The only bad thing is that I probably won't be brewing for a few months so I won't be able to see if it's accurate for awhile....but that you for all of the positive (maybe?) criticism and advice..
Well if thats the case this thread should be obsolete very soon! Ha I will try and recalibrate it tomorrow and see how that goes. The only bad thing is that I probably won't be brewing for a few months so I won't be able to see if it's accurate for awhile....but that you for all of the positive (maybe?) criticism and advice..
I keep a test tube of distilled water in the case with the refractomter. It's a good idea to calibrate before every use.
I was only giving you a hard time because you said this is ANOTHER malfunctioning refractometer thread, like there's some epidemic out there, and honestly there's NEVER been a malfunctioning refractometer thread on here, that I've seen. It may appear if you look at the titles, but the reality is, that, just like this tread, the user wasn't doing something right, like not calibrating with distilled.
It's not too different from new brewer's starting a thread titled, "Another infection thread" in reality those too turn out to be false alarms, mostly new brewer panic threads." If you look at the titles you think every other batch is infected, when in reality that too is a rarity.
ClaudiusB
Well-Known Member
Don't forget to determine the Brix correction factor or ProMash will give the wrong conversion.
Catt22 and I must be lucky our Refractometers gives us the same reading with or without distilled water.
Cheers,
ClaudiusB
iaefebs
Well-Known Member
I was thinking the same thing. I don't see any difference between tap and distilled but since the wife uses distilled for the steam cleaner I use that when calibrating.
You certainly can't go wrong using distilled water and I nearly always have some around the house for various other uses. After checking a few times with both tap water and distilled, I've found that there is no discernible difference. I don't think that tap water which registered a reading on a refractometer would meet the federal regulations.
I don't.
There's two other things to consider.
1. Have you calibrated your hydrometer? Perhaps your hydrometer could be inaccurate. I know most of mine were.
2. What temperature did you take the hydrometer reading at? Temperature compensation for hydrometer readings can be very inaccurate with more than about 30F difference between the calibration and sample temperature.
FWIW, I found that the default brix correction factor of 1.04 in Promash gave me good accuracy when brewing pale ales.
-a.
1. Have you calibrated your hydrometer? Perhaps your hydrometer could be inaccurate. I know most of mine were.
2. What temperature did you take the hydrometer reading at? Temperature compensation for hydrometer readings can be very inaccurate with more than about 30F difference between the calibration and sample temperature.
FWIW, I found that the default brix correction factor of 1.04 in Promash gave me good accuracy when brewing pale ales.
-a.
Orthobrewsky
Senior Member
I can't see why distilled water would be preferable unless one is in the habit of using distilled water in beer. It seems we'd want our beer water to read zero before the beer is there.
Here's why it is considered the norm to use distilled over tap water- consitency.
Believe it or not it tool me a LONG time to find the answer on the intertetz. Everyone talks about the importance of calibrating with distilled, but almost no-where does it explain why.
Everybody's water is going to be different, everyone's plumbing is going to be different, we know from brewing that different regions have water with different mineral content- Like Burton on trent for instance. Even boiling different waters aren't going to make them all the same.
The idea is that distilled water is going to be the most consistant due to the process of distillation.
It's going to be the most purest and free of minerals.
BUT if you start reading forums about fishtanks and such you'll see that the argument is not Tap water vs Distilled water, it's Calibration Fluid vs Distilled water.
This is an interesting article about even the difference between cali fluid and distilled;
Granted with fish it's life and death, and a few points difference in gravity of out beer isn't going to probably be all that different, even between tap and distilled...BUT hopefully now you can see why distilled is the hobby norm for calibration.
You basically want to zero out your test device, and you want to know it is zero, or whatever the calibration standard is. It's like check the accuracy of a scale in the old days with a standard weight set. You want to trust that a gram is really a gram, before you measure whatever is important to you.
Believe it or not it tool me a LONG time to find the answer on the intertetz. Everyone talks about the importance of calibrating with distilled, but almost no-where does it explain why.
Everybody's water is going to be different, everyone's plumbing is going to be different, we know from brewing that different regions have water with different mineral content- Like Burton on trent for instance. Even boiling different waters aren't going to make them all the same.
The idea is that distilled water is going to be the most consistant due to the process of distillation.
It's going to be the most purest and free of minerals.
BUT if you start reading forums about fishtanks and such you'll see that the argument is not Tap water vs Distilled water, it's Calibration Fluid vs Distilled water.
In the case of a refractometer, the reference standard is generally a fluid that has been prepared or standardized on instrumentation that is traceable to a nationally or internationally recognized source; alternatively, it may be a fluid such as distilled water that has accepted physical properties. Traceability relates individual refractometer results through an unbroken chain of calibrations back to a national standard, a fundamental physical property, international standards, or a consensus standard. At MISCO, we provide traceability back to the U.S. National Institute of Standards and Technology (“NIST”
This is an interesting article about even the difference between cali fluid and distilled;
Granted with fish it's life and death, and a few points difference in gravity of out beer isn't going to probably be all that different, even between tap and distilled...BUT hopefully now you can see why distilled is the hobby norm for calibration.
You basically want to zero out your test device, and you want to know it is zero, or whatever the calibration standard is. It's like check the accuracy of a scale in the old days with a standard weight set. You want to trust that a gram is really a gram, before you measure whatever is important to you.
Orthobrewsky
Senior Member
This would explain why the factory sends these out calibrated with distilled water, but not why you would calibrate with distilled water. When you calibrate your device, you don't really care what the water is like in various parts of the world, but only with what your water is like today for your brew.
To zero a scale, you don't need a standard weight set. Using a standard weight set to correct a scale would correspond to finding a correction factor for your refractometer when using it with wort as opposed to clear sugar water. Zeroing a scale would correspond to zeroing your refractometer.
From what I've heard, it doesn't sound like it makes much difference whether we use distilled or tap water. However, to the extent that it may make a difference, it certainly seems we should use the water with which we brew. Here's an analogy:
The scales we use to weigh our ingredients may arrive from the factory "zeroed." If so, they will calibrate zero by using no basket on top. The reason is for consistency. We all use different baskets to hold our ingredients together on the scale for weighing. However, I want my scale to read zero when my empty basket is on it. An empty basket is weight on the scale, but it is not what we want to measure, so we treat it as if its weight is zero, so that we get the weight of our ingredients. When it comes to using a refractometer to measure the sugars we place in our water, we want to measure those only. The tap water or spring water is only the "basket" we use to hold our extract. Even your hydrometer may not read zero if you have a lot of mineral content in your water. To find our how much sugar you have dissolved in that same high mineral water, you'd want to zero your hydrometer (not normally possible except by subtraction) to the high mineral water not to distilled water.
A mathematical proof:
Specific gravity minus 1 is a linear function of the ingredients we put in our wort. The vertical intercept of that linear function is zero--the equation is of the form y = mx. If we put in 3 times as much extract, we expect 3 times the number of gravity points. As I understand it, Brix is not precisely a linear function, with vertical intercept zero, of specific gravity since the conversion formula is not as simple as y = mx. However, it is extremely close to such a linear function. So much so that that I can't detect the difference between a standard conversion table and the formula y = 4x (x=brix and y=(SG-1)*1000, of course) until I reach a level in the neighborhood of SG=1.080 and then it is so close it is hard to care about the difference. Furthermore, even at that level and beyond, 4x hits below the true conversion, so (4 + very little)x would be an even closer linear function. Thus, since the function between brix and gravity points is (almost precisely) linear with vertical intercept zero, and the function between gravity points and dissolved sugars is linear with vertical intercept zero, the composition of these two linear functions is (almost precisely) linear with with vertical intercept zero. Given that what we wish to measure is dissolved sugar (not mineral content), we should zero our refractometers with our brewing water rather than with distilled water.
There also is the question of how accurate the hydrometer is. Mine reads .002 high.
wolfman_48442
Well-Known Member
With mine, I use a turkey baster to take more than I need for the sample and drop it in a clean shot glass. Then I let all the bits of stuff settle down, cool, etc and then take my reading. I then have a bit left over for a taste sample.
Average of three readings since I usually forget something and will get at least 1 wack reading...
I get a little bit of partical matter in my samples too, I put it down to hop/break material. From what I have read it might affect the sharpness of the divide (it will be more fuzzy) but not the actual reading as it is a solid suspended in the liquid and therfore not changing the liquids properties. Of coarse I could have read it wrong
I think that makes a good case for using tap water to calibrate instruments when brewing. For most waters, I don't think there will be a measurable difference between tap and distilled water when using an hydrometer to take the measurements, but let's say that distilled water reads 1.000 and tap water reads 1.002.
Now suppose you make two identical brews, one with distilled water, and one with tap water. The brew made with the tap water will have an OG and FG 2 points higher than the distilled water brew (assuming they were identical except for the source of the water).
If you calibrated your hydrometer is distilled water, then all of your readings will read 2 points high, but if you calibrated it tap water, then the readings would automatically correct for the higher density of the tap water. Brewers are interested in the amount that the gravity increases from a know starting point.
In the case of aquariums, the fish don't give a damn about the density of the water, but they care very much about the dissolved solids, so in that case you do want your instruments calibrated against a know and reliable standard. They want an absolute reading.
-a.
wildwest450
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Refractometers should come with a tongue, then they could at least lick your balls.
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Orthobrewsky
Senior Member
I broke down and got one (deeply on sale) after struggling with extracting hydrometer samples to see when a perpetually bubbling beer was really finished. So far as that part of things goes, I don't need to zero it and I don't need a correction factor. I just need to see that my brix reading, whatever that may really mean, has stopped moving. It's still a new toy and I envision taking a preboil hydrometer reading, computing a correction factor, (I may just throw the sample in the boil later) and a final hydrometer reading (there's always enough leftover for that when I bottle). So, what it can do for me is let me take instant readings during the boil to see what SG I'm getting to and during fermentation to see when I'm finished.
Marquez
Well-Known Member
That's brewer's gold!
Orthobrewsky
Senior Member
There is something at the front end of it that pretty much moves like a tongue, but it doesn't move by itself. Still, it could be a nice feature.
