Refractometer

[Steve3730]

What is everyones opinion on these? Personally one of the most annoying and messy things in brewing is filling the tube and measuring the gravity with the hydrometer.

So besides cost what are the cons to a refractometer?

 

[fartinmartin]

Refractometers, fantastic, there arnt any cons !
Once you learn the instrument you will use it, if you don't learn the instrument you will probably like so many talk it down unjustifiably.
Just remember, once the yeast is pitched you have to take a reading and convert it.

 

[Brewsncrabs]

For some reason, mine never gives the same reading twice. I could take 10 back to back readings and they would all be different. Not sure how you can tell if you're buying a "good" one or not. Mine was about $60 from one of the large on line retailers. I use the hydrometer exclusively now and feel confident of the readings.


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[Owly055]

I only use the refractometer, and I DON'T correct......... there really is no reason to once you get it figured out. I know what my original gravity should read and where to expect it to attenuate..... I'm not running a lab, I'm making beer. With my fermenters that have spigots, it's just great.

H.W.

 

[fartinmartin]

Brewsncrabs If your are not getting the right answers , it's probably you and your brew.
If you take your sample properly the refractometer will repeat !
That means a fully mixed wort, it means no condensate in the sample, it means the same time lag ref temperature drop, it means no remaining water left over from when you last cleaned it, it means that you have cleaned off the last sample effectively , of course you have focused it and use the same eye.
It will repeat with water at 0 just the same as it will repeat a wort at 1.060.
Try , put your sample on, let it stabilise re temperature fir the auto temp correct, then read it.
Try shielding some of the light to get a clearer reading, even rotating it so that the prism is upside down, this also give a clearer reading.
The refractometer is a fantastic asset to the hobby, I do however still take one hydrometer reading and that is to really qualify my OG , on my last brew this was within .0002 of my refractometer ! What more could you want ?

 

[chawn]

I believe they're essential for testing your pre and post boil SG.
If you decide to buy one, there's a great Black Friday deal for the BREWfractometer Extreme http://www.homebrewfinds.com/. It's the best on the market for only $50.

 

[Brewsncrabs]

I try to do all of those things but won't say I am perfect at it. Even with distilled water, I will get different readings when calibrated immediately back to back. Can be off by 3-5 points. Definitely could be operator error, but I tend to think otherwise. I try every brew day, but always end up using hydrometer.


Beer and crabs were meant for each other!

 

[fartinmartin]

If you can't repeat a reading with distilled water, you don't stand a chance, may be you need an eye test .

 

[barleywhore69]

It sounds like more hassle than the hydrometer. I was just looking at one at the LHBS and thinking about how I never take hydrometer readings. At $50-$60 for a refractometer, I'll stick with the hydrometer. That is, if I actually take the time to measure gravity.

 

[Donal]

I guess, as most things related to homebrewing, its personal preference. But I will say a few drops for testing with my refractometer beats the several oz required for my hydrometer and my refract never tries to commit suicide as hydrometers are know to constantly try, rolling off the counter... which negates cost difference over time

 

[Brewsncrabs]

My eyes are fine. I do need a new refractometer though.


Beer and crabs were meant for each other!

 

[Owly055]

I try to do all of those things but won't say I am perfect at it. Even with distilled water, I will get different readings when calibrated immediately back to back. Can be off by 3-5 points. Definitely could be operator error, but I tend to think otherwise. I try every brew day, but always end up using hydrometer.


Beer and crabs were meant for each other!

Considering the fact that a refractometer is nothing more than a glass prism what's to go wrong with it except if the piece with the index marks is moving around, or the prism itself is not remaining solid with reference to everything else. which seems improbable, but really is the ONLY thing that could change. The optics in the eye piece have no effect on the reading............... refractometers come apart extremely easily. The barrel unscrews from the prism assembly. You won't damage one by taking it apart, they really are NOT a sensitive precision instrument. You might need to re-zero it with water after taking it apart, but unless you are really careless it would be difficult to seriously damage one. I believe the adjusting screw simply raises or lowers one end of the prism slightly in the housing.

This is a perfect opportunity to indulge that inner child and tear something apart. What have you got to lose. The truth is that an expensive refractometer is functionally no different than a cheap Chinese..... a piece of glass ground on an angle, some optics, and a scale. Light passing through wort doesn't know who made the prism!

H.W.

 

[Brewsncrabs]

That makes sense. I'll give it a try. Thx.


Beer and crabs were meant for each other!

 

[stevedasleeve]

I'll never go back to delicate hydrometers, broken too many and every one I have ever bought has been off a few points with distilled water. I got a Hanna digital refractometer after the last one was dropped and find it way better. No more samples but for a few drops, no waiting for samples to cool down, no sanitizing jars and turkey basters, no wasted beer... I can with the help of a spread sheet figure even fermented beer gravity.

Ymmv of course
Steve da sleeve

 

[Owly055]

That makes sense. I'll give it a try. Thx.


Beer and crabs were meant for each other!

I chuckle every time I read your "beer and crabs" thing......... imagining getting drunk and hooking up with someone and discovering you have crabs a few days later........


H.W.

 

[FarmerTed]

My eyes are fine. I do need a new refractometer though.

Temperature changes can throw your refractometer off. If you're using it outside on a cold day, and holding it in your hands, it could be warming up, and throwing off the calibration. It's best to use it indoors, with room temperature water for calibration and room temperature beer/wort for the measurements. If you've got bigass sweaty hands, maybe you should wear oven mits when you're holding it, to keep from warming up the body of the refractometer.

Cloudy samples will make the reading 'fuzzy.' When I get this, I put a small sample in the fridge for a while (sometimes overnight) to get it to clear, and then pull off the top of the sample with a pipette. Bubbles cause issues, too. If I'm having trouble focusing my eye while I'm trying to read the sample, then I'll use my cell phone to take a picture, and look at it on the computer. It takes some microadjustments to get the camera lined up right, but works pretty well.

My bet is that temperature swings are causing your problems. Sometimes it's best to load the refractometer with ambient water, zero it, then put the refractometer down for a minute or two (without removing the water) and check the calibration. You can also put most samples down for a few minutes to see if the reading drifts.

 

[barleywhore69]

I might just stick with my "wait until it hasn't bubbled for a few days" method. Usually I just leave it for 2 weeks. I've never had a bottle bomb...yet.

 

[guitarguy6]

I purchased a refractometer off ebay for about $25 and I couldn't imagine brewday without one. I can quickly check gravity at every step of the process to make sure I'm on target. I still take post boil and pre boil hydrometer readings to make sure my readings are spot on.

 

[Brewsncrabs]

Great advice everyone! Hope the op learned something as well.


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[Steve3730]

Great advice everyone! Hope the op learned something as well.


Sent from my iPad using Home Brew

I definitely have. While I did purchase 2 new hydrometers at my lhbs sale yesterday, a refratctometer will be moved up to the top of my need to buy list...stirplate will have to wait


Thanks for the input guys

 

[balrog]

I definitely have. While I did purchase 2 new hydrometers at my lhbs sale yesterday, a refratctometer will be moved up to the top of my need to buy list...stirplate will have to wait


Thanks for the input guys

FYI, building a stir plate is really pretty easy and fun. IMHO.

 

[WQDL753]

In addition to what others have said, the light source can make a difference as well. For example a "warm" fluorescent will not give the same reading as full sunlight. It's minor but can make a difference.
I did have a problem with inconsistency on the one I use at work once, I would even get different readings on the same sample! Turned out someone had dropped it, and although the barrel seemed tight on the body it had been cross threaded and was able to wiggle just enough to cause a major problem. I took the barrel off and screwed it back on straight and haven't had a problem since.

 

[Steve3730]

FYI, building a stir plate is really pretty easy and fun. IMHO.

Have any good tutorials you can recommend?

 

[ajdelange]

Refractometers are certainly easier to use than hydrometers but there are several pitfalls the major one being that they can be off by a couple °P seemingly at whim by which I mean I can't make a statement to the effect that they work really well with light beers but not with dark colored ones. Thus the only way to be sure that a refractometer reading is right is to check it against a hydrometer (or densitometer) and given that you are going to haul those out there is little point in using the refractometer.

Other problems with them are that they are perfectly useless once fermentation commences. This is for two reasons. First is that the transmission (one's you look into) are hard to read if yeast cells are present blurring the line. Second, of course, is that the alcohol increases RI just as sugar does so while the consumption of sugar is driving RI down increased alcohol content is driving it back up. Even though this is the case the conditions are predictable within a group of similar beers such that a brewery, for example, who does a batch of Olde Overshoe once or twice a week can use a refractometer to measure alcohol content of each batch of that beer provided that a calibration has been done using pycnomters or densitometer to measure true ABV (in which case they aren't perfectly useless).

 

[barleywhore69]

I would put a stir plate ahead of a refractometer on the list. Many people seem to be saying that there can be problems with refractometers and that you need to compare it to a hydrometer reading to be sure of accuracy anyway. I would go with the old standby.

 

[ggriffi]

I would put a stir plate ahead of a refractometer on the list. Many people seem to be saying that there can be problems with refractometers and that you need to compare it to a hydrometer reading to be sure of accuracy anyway. I would go with the old standby.

Got my stir plate first as well and it is a huge benefit. If it was my money thats the way I would go. I was considering a refractometer but after reading aj's post, I'm not so sure anymore because I didn't know about not being able to get a good fg reading.

 

[Steve3730]

I've decided to make my own stirplate. Haven't pulled the trigger on refractometer yet.

 

[Spellman]

Since this seems to be a good discussion on refractometers, thought I might chime in here. I had one and loved it. Last year I built a new eherms system and also got a new refractometer at the same time that had a slightly higher range and a bit clearer to read. I calibrated and used as normal. I was having massive problems with my gravity and efficiencies on the new system and every time I would check I would get different numbers. I was stumped until one day I cross checked with a hydrometer and woe, instead of 1.042 I was actually at 1.060! I pulled out my old one out of the closet and it gave me the same correct numbers. Now I wonder what I did with that bunk one, as I would like to take apart and make sure everything is lined up. Brewsncrabs your eyes are not bad, you are probably having the same issue I was with it not reading correctly.

On another note, I have been testing my final runnings on my fly sparge and it has been hitting really really low numbers. Yesterday it was reading like 1.002 which is way past the danger level. I just couldn't believe it was correct so I took a sample and used my hydrometer. After it got close to room temp the reading was 1.010. Which is about where it should be. Can't figure out why I can zero out the refractometer and have it read correctly, and it also read my gravity of 1.054 correctly, but not read the final runnings of 1.010 correctly. Any ideas?

 

[aviator01]

If you're looking for a fairly inexpensive yet useful tool get this one. http://www.amazon.com/gp/product/B00F2040LS/?tag=skimlinks_replacement-20

I just got one and so far it seems to work great. Very simple and easy to use. I purchased a huge bag of pipettes so I don't have to worry about reusing or contaminating my wort when I pick a sample. http://www.amazon.com/gp/product/B00207CO7I/?tag=skimlinks_replacement-20


The two drops on the refractometer is much easier than the several ounces needed for my hydrometer.

 

[dmcman73]

Have any good tutorials you can recommend?

I built my own, I included the link in this thread: https://www.homebrewtalk.com/f11/built-my-first-stir-plate-today-504458/ of the tutorial I used and it worked awesome.

The important thing is to keep the magnets a good distance from the fan so it does not interfere with the motor.

Back on topic, I use a digital refractometer and it's worked great for me, I use it in conjunction with this calculator: https://play.google.com/store/apps/details?id=com.brewzor.calculator&hl=en

Most will say to use other online calculators but if they don't have a calibration function on it, I find them not as accurate. The Brewzor calculator has a drop down in the Refractometer calculator labeled "Calibrate". For the first time, take a measurement of your unpitched wort with your hydrometer and enter that value, then take a measurement with your refratcoemter (digital or manual one) and enter that value. The calculator will calibrate and you'll be surprised how it will be dead on with both values after that.

EDIT: This is the one I bought: http://www.amazon.com/dp/B007Z4IN58/?tag=skimlinks_replacement-20

 

[bford]

Where's the best how to use a refractometer video or tutorial? I just got mine in....

I brew small two gallon batches so wasting all the wort on hydrometer readings just isn't smart (not for profit) home business...

 

[dmcman73]

Where's the best how to use a refractometer video or tutorial? I just got mine in....

I brew small two gallon batches so wasting all the wort on hydrometer readings just isn't smart (not for profit) home business...

Digital or manual?

Either one to use is quite simple, just two different ways to read it. The important thing is that you calibrate it prior to each use using a drop of distilled water on the lens, it should read 0 on either the manual one or the digital one.

The digital one is easy to calibrate, place some distilled water on the lens, wait a few seconds for the temp to stabilize and press the "Zero" button. Once the display shows 0, wipe the lens clean of the water and then place a drop of your wort on it, wait a few seconds for the temp to stabilize and then press the read button.

For the manual one, flip the plastic cover up off the lens, place some distilled water on the lens and then flip the plastic cover down again, wait a few seconds for the temp to adjust then make sure it reads 0 or 0.000 while looking through the lens, if it does not there is an adjustment screw on it you will need to turn with a fine small screw driver (should come with one), you should be able to turn the screw as you are looking though the lens. Wipe it clean and then place some wort on the lens of the manual one the same exact way you did with the distilled water, wait a few seconds then look through the lens to read it. If your manual refractometer has both Brix (bx) and gravity readings, I would ignore the gravity reading and record the birx one. Those Gravity readings on them are never accurate and you'll get a more accurate reading using a Brix to Gravity calculator.

EDIT: I should note that the adjustment screw should be located under that small black plug on the body of the refractometer.

 

[bford]

Thanks... I have one of the manual versions...

 

[WissahickonBrew]

I will apply all of the tips mentioned so far in this thread, thank you one and all.

Does anyone have a suggestion related to the the light source for the reading? Is it imperative to go outside to get the better reading? Will fluorescent or incandescent lights throw the reading way off?

I am also wondering if there is a good formula to use when taking readings post fermentation to adjust for alcohol content? I am getting readings that seem way to low for what my recipe projected!

Thanks again all!

 

[balrog]

Is it imperative to go outside to get the better reading? Will fluorescent or incandescent lights throw the reading way off?

I wonder same thing, having just started using mine. I've noticed no perceptible diff between a daylight source reading and a tungsten lightbulb source reading, but I've not compared CFL, fluorescent or LED bulbs yet.

I am also wondering if there is a good formula to use when taking readings post fermentation to adjust for alcohol content?

I've Googled several.
http://www.brewersfriend.com/refractometer-calculator/
http://www.northernbrewer.com/refractometer-calculator/
http://seanterrill.com/2011/04/07/refractometer-fg-results/

And a lot of interesting reading for back-guessing OG when you have refractometer and hydrometer end SG readings:
http://www.woodlandbrew.com/2013/02/refractometer-summary-of-equations.html

 

[ajdelange]

The refractive indices for sucrose solutions (on which the scales of these refractometers are based) were measured by ICUMSA at 546 nm (green mercury line) and 589 nm (yellow sodium line) so that dispersion could be estimated and indeed the ICUMSA polynomial includes a term that allows one to calculate the RI for any temperature, wavelength and strength w/w and thereby construct a Bx scale. The important point is that the light used should be narrowband and preferreably in the yellow/green part of the spectrum. Using broadband light will result in dark to light border that is not sharp. Given the other inaccuracies associated with refractometers the additional error introduced by this blur may be insignificant. Note that the digital instruments contain an internal light source and the internal math will be tuned for the wavelength of that light source.

 

[Steve3730]

So overall its seems like refractometer best for during boil and pre pitch checks hydrometer still best for FG.

I brewed thus past weekend and cooling the cup of wort to check gravity took almost my entire boil time. Leaves little room to make corrections

 

[dmcman73]

So overall its seems like refractometer best for during boil and pre pitch checks hydrometer still best for FG.

I brewed thus past weekend and cooling the cup of wort to check gravity took almost my entire boil time. Leaves little room to make corrections

I use mine for FG as well and it is spot on with my Hydrometer readings. I use and Android app call brewzor calculator. Once calibrated to your Hydrometer and Refractometer, it does a really good job in the conversion.

 

[LLBeanJ]

I have a cheapo $30 Amazon.com refractometer and had issues with repeatability when I first started using it. Due to that, I stopped using it for a while, but 4 or 5 brew days back decided to give it another try. After a little experimentation and some practice I found that I was able to get reliable results and now use it exclusively for OG readings. I still use the hydrometer for FG so I can drink the sample.

 

[ajdelange]

I use mine for FG as well and it is spot on with my Hydrometer readings. I use and Android app call brewzor calculator. Once calibrated to your Hydrometer and Refractometer, it does a really good job in the conversion.

Except when it doesn't. How do you know when you have one of those situations?