Refractometer

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Indiana Red

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I'm fine with the hydrometer method, but I'd like to take the next step with one of these as it seems like dealing with just a drop or two would be a bit less hassle.
Which do you have, do you like it, is it worth it to you and do the cheep ones ($20ish) work just as good?
 

jwalker1140

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I've been using a cheap refractometer for about 6 years now, for both brewing and winemaking, and I absolutely love it.

You'll hear comments about how refractometers shouldn't be used after fermentation starts and how alcohol throws off the result. I did a lot of reading and hand wringing, and it was the considerable amount of parallel testing I did that convinced me there wasn't a meaningful difference between the two in terms of accuracy, provided you use a conversion spreadsheet.

Personally, I can't imagine going back to a hydrometer, but YMMV.
 

mongoose33

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I've been using a cheap refractometer for about 6 years now, for both brewing and winemaking, and I absolutely love it.

You'll hear comments about how refractometers shouldn't be used after fermentation starts and how alcohol throws off the result. I did a lot of reading and hand wringing, and it was the considerable amount of parallel testing I did that convinced me there wasn't a meaningful difference between the two in terms of accuracy, provided you use a conversion spreadsheet.

Personally, I can't imagine going back to a hydrometer, but YMMV.
Is there a particular spreadsheet you would suggest?
 

Craftfan

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Is there a particular spreadsheet you would suggest?

http://www.brewersfriend.com/refractometer-calculator/

Here is the one I use. I have used a refractometer exclusively as well, and recently just picked up a hydrometer to see how much of a difference there really was. The last two batches have been nearly identical. Wasting 2-3 ounces of beer doesn't appeal to me. Especially if you take 2-3 readings. I know it's not much, but it's still a waste. And if you put the hydrometer in a fermenting bucket, it is almost impossible to read. Every bubble and hop particle seems to gravitate to the thing making it almost unreadable. Not to mention if it breaks in your fermenter because you drop it/temp fluctuation/whatever, the batch is gone.

I have an ATC fleabay cheapo model and love it. I calibrate it every use, and has never needed adjustment.

I'm new to the hobby, so take my advice for what it's worth.
There are some who over analyze and need every measurement to be exactly precise. I'm not that guy. Measurements say 7.765" pre boil? 7.75" is close enough for me. You will have to decide for yourself how exact is exact enough for you.

Here is what it comes down to. If I take a FG reading at 1.015 with my refractometer, do I really care if it is 1.013-1.014 on my hydrometer? I don't. If you do, get a hydrometer. .1-.2 ABV is close enough for me.
 

Qhrumphf

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I use a refractometer for everything pre-fermentation, and a narrow range hydrometer for post-fermentation. I've seen many talk up Sean Terrill's calculator, but I still doubt it (rightly or wrongly). But accuracy aside, part of it is getting to taste the sample, and potentially perform other tests like pH. Which you can't meaningfully do with just a drop or two for a refractometer.

Now, if I do another 1 gallon something (it's been a long time), then that's another story, because there the loss for a hydrometer sample is a bit more significant.
 

Craftfan

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I use a refractometer for everything pre-fermentation, and a narrow range hydrometer for post-fermentation. I've seen many talk up Sean Terrill's calculator, but I still doubt it (rightly or wrongly). But accuracy aside, part of it is getting to taste the sample, and potentially perform other tests like pH. Which you can't meaningfully do with just a drop or two for a refractometer.

Now, if I do another 1 gallon something (it's been a long time), then that's another story, because there the loss for a hydrometer sample is a bit more significant.

You doubt it why? Have you done any sort of test on it? I'm truly not trying to be argumentative, I would just like to know what variations have been seen from people who use hydrometer and refractometer readings to verify the results.
 

Qhrumphf

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You doubt it why? Have you done any sort of test on it? I'm truly not trying to be argumentative, I would just like to know what variations have been seen from people who use hydrometer and refractometer readings to verify the results.
I haven't. And folks who have done so have found them immeasurably close. But online calculators cannot predict a very complex situation like that 100%.

So I'm not discouraging anyone from using a (corrected) refractometer reading for FG. For the other reasons I said, I'm fine using a hydrometer.

Plus a pro tried to convince me we shouldn't be using refractometers at all. He didn't elaborate, but presumably due to refractive index. But calibrate with similar known wort and not water and you're fine there too, and even then with water it's still so small that misreading the line will get you as far off. And the bad SG lines are even worse (just work in Brix/Plato/Balling, makes like easier until you have to translate for others).

Point is I'm confident enough in my measurements.
 

Craftfan

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I haven't. And folks who have done so have found them immeasurably close. But online calculators cannot predict a very complex situation like that 100%.

So I'm not discouraging anyone from using a (corrected) refractometer reading for FG. For the other reasons I said, I'm fine using a hydrometer.

Plus a pro tried to convince me we shouldn't be using refractometers at all. He didn't elaborate, but presumably due to refractive index. But calibrate with similar known wort and not water and you're fine there too, and even then with water it's still so small that misreading the line will get you as far off. And the bad SG lines are even worse (just work in Brix/Plato/Balling, makes like easier until you have to translate for others).

Point is I'm confident enough in my measurements.

Perfect answer. Thanks for the reply.
 

jwalker1140

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Here's another way to think about it: what are you really trying to determine when taking a FG reading?

Are you just trying to determine if fermentation is done? If so, then either tool will work since you're simply looking for a stable reading.

Are you trying to determine if you've hit your FG target? If so, why in the world would some abstract number be more important than your taste buds? Does the beer taste too dry to you? Who cares whether the true reading is 1.012 vs 1.011, mash higher next time or change the recipe. Is the body too full? Mash lower or change the recipe. I look at this like the different IBU formulas. Pick one, understand how the numbers relate to what you're tasting, and move on. Again, I haven't noticed a meaningful difference in readings between my refractometer and hydrometer, but I don't see why it would matter even if I did.
 

Spartan1979

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I've got a Hanna Digital Refractometer and I like it. No guessing where the fuzzy line is. Push a button and get an exact number. Not cheap though and my wife bought for me as a Christmas Gift.
 

MagicMatt

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I own a cheaper refractometer ($30 or so) and I find I still gravitate toward the hydrometer for my main readings (OG, FG). What I like the refractometer for is to check the quickies - like end of running gravity, preboil gravity, or a quick OG reading to ensure the boil really is done.

The main problem I have with the refractometer's readings is that it is inconsistent. Take a shot glass sized sample, put several drops on the refractometer and get a reading of say 10.2 Brix. Rinse the refractometer with distilled water, dry, apply another few drops from the same sample and get 10.6 Brix. Do it a third time and get 10.0. It's gotten to the point where I now take 5 readings per sample and average them. Sometimes 4 of the 5 are identical, sometimes every one is different. Another issue is the line is so hard to read, as it's not a distinct hard line, but a blurring of white to blue that happens over the span of say 0.4 Brix or so. I generally aim for the middle of this area to get my reading.

But when it comes down to it, there's nothing as precise as the hydrometer. I'll often find my hydrometer reading is a point or two off of my refractometer reading. When this happens I always trust the hydrometer.
 

Qhrumphf

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I own a cheaper refractometer ($30 or so) and I find I still gravitate toward the hydrometer for my main readings (OG, FG). What I like the refractometer for is to check the quickies - like end of running gravity, preboil gravity, or a quick OG reading to ensure the boil really is done.

The main problem I have with the refractometer's readings is that it is inconsistent. Take a shot glass sized sample, put several drops on the refractometer and get a reading of say 10.2 Brix. Rinse the refractometer with distilled water, dry, apply another few drops from the same sample and get 10.6 Brix. Do it a third time and get 10.0. It's gotten to the point where I now take 5 readings per sample and average them. Sometimes 4 of the 5 are identical, sometimes every one is different. Another issue is the line is so hard to read, as it's not a distinct hard line, but a blurring of white to blue that happens over the span of say 0.4 Brix or so. I generally aim for the middle of this area to get my reading.

But when it comes down to it, there's nothing as precise as the hydrometer. I'll often find my hydrometer reading is a point or two off of my refractometer reading. When this happens I always trust the hydrometer.
Are you allowing the few drops to sit on there a bit before reading, or reading right away? Even with ATC, the instructions with mine said to let it sit for ~30 seconds to allow the temp between the lens and the sample to equalise. Doing so, my readings are always very consistent. And my line is sharp as day even after several years of use.
 

jwalker1140

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Odd, I've never experienced that sort of variance between readings, and my line also is pretty sharp, maybe 0.05 Brix wide. The only exception is when I take readings in the middle of a wine ferment, when there are little bits of grape skins floating around in solution. (And the only reason I take readings in the middle of a wine ferment is to time nutrient additions. I wouldn't bother taking a reading in the middle of a beer ferment).

Makes me wonder if there's something wrong with your refractometer, like your focus dial isn't working properly? I know that's obvious, just thinking out loud....
 

UndeadFred

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Best tool I own for brewing. I don't have issues with inconsistent readings. Mine was super cheap.. Brix only I convert using Brewer's Friend free app on my phone. Works great.

I will often measure FG with the hydrometer but every other reading I even do it with the refractometer. It gives you a lot of freedom to tweak instead of having to do exact calculations pre boil.
 

MagicMatt

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There's nothing wrong with it, it's just how the cheap ones work. You get what you pay for, and should use it as such. I've used 3 different models of <$100 refractometers (2 were <$50) and seen roughly the same results. There are times when they seem to be consistent, and there are times when they definitely are not. Just when you think you can trust it, it throws a whack reading. This may not be your experience, but it is mine. As I said, sometimes it's consistent 4/5 times in a row, sometimes not at all. Because of this I use it as a quick reading tool, an aide so to speak, not necessarily a precise scientific instrument. At this price point, to me it's a scientific toy. And it's great for those quick readings. But to each their own.

I keep a few shot glasses in the freezer and use them to draw my samples (from mash for pH, from sparge or kettle for gravity readings), and let them sit for about 5 minutes before using. I always measure temps first, and they're never more than 80°F. I do allow time for the refractometer to adjust, and I always check calibration with distilled water. It's just the scale is so tiny on most models, it makes it hard to see. The line is definitely distinct, but it's just not as sharp as I'd like it. I'll try to take a pic.
 

GuldTuborg

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Here's another way to think about it: what are you really trying to determine when taking a FG reading?

Are you just trying to determine if fermentation is done? If so, then either tool will work since you're simply looking for a stable reading.

Are you trying to determine if you've hit your FG target? If so, why in the world would some abstract number be more important than your taste buds? Does the beer taste too dry to you? Who cares whether the true reading is 1.012 vs 1.011, mash higher next time or change the recipe. Is the body too full? Mash lower or change the recipe. I look at this like the different IBU formulas. Pick one, understand how the numbers relate to what you're tasting, and move on. Again, I haven't noticed a meaningful difference in readings between my refractometer and hydrometer, but I don't see why it would matter even if I did.
Best answer on this thread. I was thinking about formulating a reply, but this one sums it all up already. The only extra detail I'd add is that it's sometimes helpful to be able to get a reasonably accurate ABV measurement. Yes, you can do that using a conversion from the refractometer reading, but using a hydrometer makes for more consistency.
 

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podz

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Plus a pro tried to convince me we shouldn't be using refractometers at all. He didn't elaborate
That's not an attempt to convince, then - that's called listen to me blindly because I'm a "pro".

Sort of reminds me of that neighbor who stops you as you're driving off and tells you to keep the windows rolled down because that new car smell will give you cancer.

Or maybe it reminds me more of a religious evangelist.

Hydrometers are wildly inaccurate for measuring any liquid which contains even the slightest traces of carbonation. Additionally, some people might just want to get a refractometer and try it because they grew up in some backwoods ****hole and are actually trying to get a grasp on science or something.
 

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I use a cheapo refractometer that I got online for $20. Just now getting around to figuring out its wort correction factor using the brewer's friends spreadsheet. After getting around 10 or so side by side measurements with the refractometer and hydrometer, they are very close to matching each other both pre and post fermentation when I use the correction factor.

I do find that my refractometer does vary with multiple samples occasionally- usually 0.1-0.5 brix. At one point I did find myself taking multiple samples to try and nail it down, but then I realized that even a variance of 0.5 is only 0.2% abv difference.... So who really cares? Now I take 2 or 3 measurements (usually only 2 if they are both within 0.5) and use the average. One thing to note- I've noticed more variance with time after taking sample when brewing outdoors in extreme temps.

The ease of using a refractometer over a hydrometer far outweighs the need to be accurate to the second decimal place for abv. This is homebrew after all.

Good point about hygrometer varying. I've had sg measurements taken with hydrometers vary even more due to carbonation, temperature variances, and other unknown factors.
 

Qhrumphf

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That's not an attempt to convince, then - that's called listen to me blindly because I'm a "pro".

Sort of reminds me of that neighbor who stops you as you're driving off and tells you to keep the windows rolled down because that new car smell will give you cancer.

Or maybe it reminds me more of a religious evangelist.

Hydrometers are wildly inaccurate for measuring any liquid which contains even the slightest traces of carbonation. Additionally, some people might just want to get a refractometer and try it because they grew up in some backwoods ****hole and are actually trying to get a grasp on science or something.
All devices have limitations. It's simply knowing those limitations and being able to work with them.
 

DurtyChemist

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How do you guys calibrate your refractometer? Wort? Distilled water? Tap water? Sugar dissolves in water?
 

Qhrumphf

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I just use tap water. Any discrepancy there is going to be within margin of error of my reading it anyway.

If you want to be really thorough, measure a sample of wort with a hydrometer that you are sure is accurate (measuring exactly 1.000 in distilled water at reference temp is probably good enough, but if you can two point calibrate it even better just in case the scale is off). And then calibrate your refractometer based on that. If I understand correctly, that should calibrate your refractometer so that even the refractive index of wort is accounted for (it's very slightly off otherwise as refractometers measure sucrose solutions, and the refraction of maltose is slightly different). Of course, being super-super thorough would require you to calibrate with your actual wort you're measuring , as different worts will have different sugar concentrations and thus different refractive indexes. Which if you'd ultimately have to measure with a hydrometer anyway, it makes the refractometer pointless.

Not suggesting you do that, just be aware of the limitations of your instrument.
 

fun4stuff

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I just use tap water. Any discrepancy there is going to be within margin of error of my reading it anyway.

If you want to be really thorough, measure a sample of wort with a hydrometer that you are sure is accurate (measuring exactly 1.000 in distilled water at reference temp is probably good enough, but if you can two point calibrate it even better just in case the scale is off). And then calibrate your refractometer based on that. If I understand correctly, that should calibrate your refractometer so that even the refractive index of wort is accounted for (it's very slightly off otherwise as refractometers measure sucrose solutions, and the refraction of maltose is slightly different). Of course, being super-super thorough would require you to calibrate with your actual wort you're measuring , as different worts will have different sugar concentrations and thus different refractive indexes. Which if you'd ultimately have to measure with a hydrometer anyway, it makes the refractometer pointless.

Not suggesting you do that, just be aware of the limitations of your instrument.
I think few people understand how to correctly use a refractometer with beer.

You calibrate it with distilled water. Then you need to determine the wort correction factor specific to your refractometer.


http://www.brewersfriend.com/how-to-determine-your-refractometers-wort-correction-factor/
 

Qhrumphf

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I think few people understand how to correctly use a refractometer with beer.

You calibrate it with distilled water. Then you need to determine the wort correction factor specific to your refractometer.


http://www.brewersfriend.com/how-to-determine-your-refractometers-wort-correction-factor/
Which is still an averaged figure. That's why your article suggests sampling multiple times from different worts. Because unlike a pure sucrose solution (which is what both Brix and most refractometers are designed to measure), wort is NOT a uniform sugar source and will contain different levels of maltose, glucose, fructose, sucrose, maltotriose, etc. And in no way is that ratio consistent between batches. If it was, no one would ever be worrying about things like mash temperature.

But yes. An averaged correction is better than no correction at all. But ultimately it's still making assumptions, and a hydrometer is more foolproof in that regard, but a much bigger PITA to take readings with.
 
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Then you need to determine the wort correction factor specific to your refractometer.
*wort

a hydrometer is more foolproof in that regard, but a much bigger PITA to take readings with.
I've been doing this a long time and compared to all the processes involved in making beer, using a hydrometer is amazingly simple.

I wish I could use my refractometer to measure beer ABV, but I have tried and failed (due to lack effort I think). Wort correction factor? I don't make the same beer twice, not often anyway. I only use my refractometer during the boil (every time).
 

Qhrumphf

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*wort



I've been doing this a long time and compared to all the processes involved in making beer, using a hydrometer is amazingly simple.

I wish I could use my refractometer to measure beer ABV, but I have tried and failed (due to lack effort I think). Wort correction factor? I don't make the same beer twice, not often anyway. I only use my refractometer during the boil (every time).
Depends on when. It's chilling the sample I find a PITA. Taking a reading if your runnings gravity, or your preboil gravity, and having to chill down an entire hydrometer sample isn't my cup of tea, as opposed to literally only chilling a few drops for your refractometer.
 
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Depends on when. It's chilling the sample I find a PITA. Taking a reading if your runnings gravity, or your preboil gravity, and having to chill down an entire hydrometer sample isn't my cup of tea, as opposed to literally only chilling a few drops for your refractometer.
Like I said, I use the refract every time during the boil. My boil time is depends on that measurement.

I ONLY use it for the boil. Otherwise, hydrometer FTW.
 

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Like I said, I use the refract every time during the boil. My boil time is depends on that measurement.

I ONLY use it for the boil. Otherwise, hydrometer FTW.
I find it much easier to obtain only a drop than a whole cylinder full of wort, so I prefer the refractometer for checking to confirm fermentation is done. Not only is it easier, but fermentor is exposed to air for a shorter time (3 seconds vs. 1 minute for hydrometer) and less wort wasted. Then can also calculate FG and abv from these samples. My hydrometer is collecting dust now.

After calculating my wort correction factor (3-5x samples from prior yeast starters and different worts from 10+ batches), SG has matched my hydrometer by +/- 0.001. Was expecting it to be off when I made a chocolate stout a couple months ago for reasons mentioned by poster above- it was dead on for OG and FG compared to the hydrometer.
 

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Nope, it's "specific to your instrument."

E.g. http://www.brewersfriend.com/how-to-determine-your-refractometers-wort-correction-factor/ Second paragraph, last sentence.

Most people on these forums seem to have wcf's ranging from 0.9-1.1 which is specific to their instrument, but pretty similar with worts. Mine ranges from 0.92X - 0.93X (light ales to dark stouts). Only time it was different was when OG was 1.150, where it was 0.96. As long as my OGs were between 1.040 and 1.080, I did not see much variance to the hundredths place.
 
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Nope, it's "specific to your instrument."

E.g. http://www.brewersfriend.com/how-to-determine-your-refractometers-wort-correction-factor/ Second paragraph, last sentence.

Most people on these forums seem to have wcf's ranging from 0.9-1.1 which is specific to their instrument, but pretty similar with worts. Mine ranges from 0.92X - 0.93X (light ales to dark stouts). Only time it was different was when OG was 1.150, where it was 0.96. As long as my OGs were between 1.040 and 1.080, I did not see much variance to the hundredths place.
Hmmm - I see. I did a lot of experiments many years back trying to get my refractometer to measure gravity after the yeast was added. I would calibrate it to a light beer but then have wild inaccuracies with the next beer, usually when a different color or different hop content. After a LOT of frustration, I just use a hydrometer now after the boil.

Maybe I'll have to revisit this.
 
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