Refractometer Accuracy Testing for Homebrewers

[@DavidHeathHomebrew]

A follow up to this video is coming on the 1st of November, where I test two high gravity samples.

[@KegLand]

Top work. Thanks for this video David. Everyone loves a good side by side comparison.

[@DavidHeathHomebrew]

Cheers guys, much appreciated 🍻🍻🍻

[@hombredeletras8112]

Thanks for making this David, I think these are really interesting little tests and evidently from the comments is super helpful to folks and a very popular format. One (unsolicited) suggestion for the follow up video you’re planning would be to, in addition to using wort, make up a range of different gravity solutions across the typical brewing range using distilled water and sugar so you have values of a known quantity (after applying wort correction factor) as in this video we are using the SmartRef as our reference measurement without having verified this against a set of known values across the intended range. The SmartRef may well have the advertised accuracy, but it would be dead simple to prove it in the interests of completeness and best scientific practice I look forward to the follow up, thanks again Cheers!

[@DavidHeathHomebrew]

Great, many thanks for you suggestions. I really want to stay with an all grain wort for these tests. I will be putting together a high gravity one next which is coming up over this weekend for testing and filming.

[@dennispurdy3533]

I use the cheaper one like you showed. I first calibrated it for plain water but when I tried using it with my hot wort that had full starting gravity it was way off by comparison to my hydrometer. So when the wort was cooled down I calibrated the refractometer to match my hydrometer. Now several brew batches later it still matches my hydrometer at full starting gravity.. however it reads way to low on plain water. I have also learned that it reads about one brix too low when the wort is hot but it seems consistent in that way. So for me only needing to read wort with full gravity it works great. thanks for the video.

[@DavidHeathHomebrew]

Great, glad you enjoyed this one. I touched on this within the video but the Blue box type vary a lot as they are copied greatly throughout China. You can get lucky or unlucky, however hydrometers also vary too as I have also covered in a previous test found here:- kzbin.info/www/bejne/jKetdpR-nLR6mZosi=Mj60TJqABirX0fnO

[@simonc3847]

Thanks for doing this. If I may suggest, I would have liked to also see the reading of your wort from a standard hydrometer, as comparison with the more technical devices, because using one is so cheap. Plus some approximation of the differing costs between devices (e.g. SmartRef is generally 10x price of NoBrand, or something similar) - as lower margin of error is expected as price increases. Just a suggestion, perhaps in the notes.

[@DavidHeathHomebrew]

Hi, many thanks for your feedback. Actually I already did a test like the one you suggest which is available at this link:- kzbin.info/www/bejne/jKetdpR-nLR6mZosi=Mj60TJqABirX0fnO In terms of price this is something I avoid because my channel is viewed in many countries and especially these days prices are very much subject to change. Cheers 🍻🍻🍻

[@simonc3847]

@@DavidHeathHomebrew Great! - very interesting to see that also, thank you!🍻

[@DavidHeathHomebrew]

Cheers 🍻🍻🍻

[@brewingbadTN]

Thanks, David! Would have loved to see a standard hydrometer reading as well for comparison. Maybe next time. Cheers 🍻

[@DavidHeathHomebrew]

I already did such a test which can be found here:- kzbin.info/www/bejne/jKetdpR-nLR6mZosi=Mj60TJqABirX0fnO This video was refractometer focussed 🍻🍻

[@brewingbadTN]

@@DavidHeathHomebrew Thank you!

[@DavidHeathHomebrew]

@brewingbadTN 🍻🍻🍻

[@lafamillecarrington]

I use a cheap(ish) refractometer for all my readings, correcting for alcohol content as necessary. Whilst this may not be perfectly accurate, it is certainly good enough to warn me of any problems during the brewing process.

[@DavidHeathHomebrew]

Yes, it sure is.

[@johnpantling9284]

Hi David like most of your videos this was very comprehensive thank you. For my part I I use a cheap blue box refractometer and to be fair to it for the price it is excellent. I used my hydrometer to standardise my refractometer. I chose three different sugar concentrations and check the hydrometer zero using distilled water my hydometer was surprisingly accurate! I have to be honest my refract did not show a reading more than 0.001 sg at any of the three chosen sugar concs. I further used my hydrometer and refractometer over several mashes taking samples at different intervals. After taking some twenty diferent sample readings over various brews I could not split my hydrometer and my refractometer by more than 1 to 2 points . So my take is that for the average home brewer a cheap blue box refract is adiquate we are not selling a product and if the error is so small calculated ABV values will not be badly effected.

[@DavidHeathHomebrew]

Hi John, Do keep in mind that most of the cheap glass hydrometers are also varying in accuracy. You never really know until you have something much more expensive how accurate you are. It is of course argueable if this is an issue though, if you are happy with the actual beer results.

[@johnturner2890]

I use a generic blue box refractometer while brewing just for a guide but use a conventional hydrometer for taking my actual readings, I certainly don't rely on the refractometer due to its suspect accuracy. Call me old school but I do prefer a hydrometer and can't really justify the expense buying a digital one.

[@DavidHeathHomebrew]

Fair play. Yes, I only recommend refractometers for during the brew. After that its hydrometers or density meters 🍻🍻🍻

[@curtpick628]

Great comparison, David!

[@DavidHeathHomebrew]

Cheers Curt, much appreciated 🍻🍻

[@NoMusiciansInMusicAnymore]

It would have been really good to see these comparisons but with temperature differences as one of the big bonuses with the refractometers is that you can use high temp wort (assuming your refrac has temp adjustment)

[@DavidHeathHomebrew]

Ok, thanks for your input, much appreciated 🍻🍻🍻

[@NoMusiciansInMusicAnymore]

@@DavidHeathHomebrew thanks for the videos, you make pretty unique content and it's very much appreciated!

[@januszkszczotek8587]

Nice test. I suggest to additionally test this with a wort of higher gravity. An alternative could be to produce two sugar solutions of known gravity and test all devices against it (in your experiment, the SmartRef couldn't be incorrect). A few years back we tested standard homebrew hydrometers and cheap refractometers with two solutions of known (but secret) gravity - the solutions were distributed to several people, who tested with their personal device(s). The result was, that all devices were "good enough" for home brewing, however the refractometers seemed a bit more precise than classic hydrometers. The reason is probably because reading the measured value on a refractometer is less error prone than correctly reading a hydrometer (surface tension).

[@DavidHeathHomebrew]

Thank you, yes I will be making a high gravity test soon after others suggested it, its a good idea. In my test the SmartRef was the benchmark unit due to its known and trusted accuracy, its actually a little more accurate than the EasyDens. These tests are certainly fun and interesting but what is «good enough» is really down to the individual.

[@AVCMMAC]

I use a bluebox refractometer for all my readings (during brewing and fermenting), but enter the brix into the Refractometer/Brix correction tool in Brewfather. I have determined my correction factor to be 1.04 by following the procedures laid out by Short Circuited Brewers. This seems to work for me just fine. Sure would like to have one of those Smart Refs though...

[@DavidHeathHomebrew]

Yes, ultimately it really depends on the level of accuracy desired. Being aware the this can vary is useful though of course.

[@leiflindqvist9095]

Most people probably understand that the cheap ones do not have the highest accuracy. But there is a methodology that can handle that problem very well and that gives good accuracy over the entire measurement range. If you make measurements with calibration fluid over the range you want to measure well. Then, with a small polynomial formula in a spreadsheet, you can get a value that is compensated for the inaccuracy. If it's worth the trouble, yes if you think that kind of thing is a bit funny, otherwise maybe not.

[@DavidHeathHomebrew]

Oh you would be surprised then. Many actually do expect high accuracy for the cheapest of instruments. This was one of the core reasons to make these videos in fact.

[@leiflindqvist9095]

@@DavidHeathHomebrew Fair enough, I'd guess that about every other person born is moderately gifted.

[@DavidHeathHomebrew]

That well could be true but it surprises me just how many people take a cheap hydrometers reading as accurate and many cannot be swayed from it even with explanation.

[@SunePedersen88]

It would be great if Kegland considered venturing into the digital refractometer market. As you said in the video the current digital refractometer offerings mainly appeal the the very high end prosumer homebrewers. If Kegland or anyone else for that matter could bridge the gap between the Saber and something like the smartref they would be at a very competitive position for that sort of product.

[@DavidHeathHomebrew]

Hey Sune, yes I agree for sure.

[@marklpaulick]

You might like the Milwaukee digital refractometer

[@DavidHeathHomebrew]

@marklpaulick 🍻🍻🍻

[@paulrobertson9439]

Very interesting thank you for taking the time to share this information. For me, I'll wait until they can invent one that works post fermentation also. Cheers :)

[@DavidHeathHomebrew]

Great, thanks Paul 🍻🍻🍻

[@bruceedwards3366]

ive calibrated my bluebox item to 1060 with my hydrometer, my PIL reads the same. This is where most of my SG starts so it works for me.

[@DavidHeathHomebrew]

If its working for you then great, the bluebox type can vary hugely.

[@GodfreyTempleton]

I ferment liquid malt extract kits in a plastic bucket then transfer to a keg, my only monitoring capabilities are temperature and gravity. The other day I transferred a batch from a bucket into a carboy due to lack of space. Temperature was right, all looked correct. I then put the airlock in, but it was quiet. Panic stations the whole thing seemed to have died. Then I got my magnifying glass out and looked at the surface and there was little bubbles coming up to the surface. Today a lot of froth on the surface and it looks right, yet the airlock is still still. Gravity is reducing. What I'm thinking is that all the measuring devices have their place yet being able to look at what's going on and then with experience make a judgement on the situation is just as important. I'm sure this batch will be okay.

[@DavidHeathHomebrew]

Sounds like something could be up with your airlocks seal. Certainly they are not to be taken too seriously as they can bubble just due to air pressure. So yes, its great to have other ways to measure 🍻🍻

[@zzing]

I use a Milwaukee digital refrac and love it, but do find a lot of variation among readings even after just waiting a minute or two - even though it should correct for temperate.

[@DavidHeathHomebrew]

Ive not tried it but this variation does not make it sound so reliable.

[@zzing]

@@DavidHeathHomebrew I have been curious if settling solids can affect it over seconds to minutes.

[@DavidHeathHomebrew]

As long as the reading is consistent after some minutes then thats ok.

[@alexandersoderholm3619]

Could you do the same test on a high gravity wort? It would be very interesting to see if the deviation stays the same or somehow scale with the gravity.

[@DavidHeathHomebrew]

I plan to do that yes at the next opportunity. This will not be straight away soon but asap 🍻🍻

[@leroygross9144]

Interesting and suprising 👍

[@DavidHeathHomebrew]

Great to hear, thanks 🍻🍻🍻

[@jakebertrand8414]

Thanks David. I may have to pick up a sabre

[@DavidHeathHomebrew]

I am impressed for the price for sure.

[@InvisibleCitizen]

I went back a few years ago and tested ALL of my brew store purchased brewing thermometers and found all but one off by at least 5 deg f. The worse was 11 deg off. Always test brewing instruments once a year!!!

[@DavidHeathHomebrew]

Yes, its a smart idea for sure 🍻🍻

[@Margarinetaylorgrease]

What’s an “f”?

[@DavidHeathHomebrew]

@Margarinetaylorgrease That would be Fahrenheit I should think 🍻🍻🍻

[@luizreboucas6063]

Hi David! Did you do any tests with higher gravity worts to know how much does the inaccuracy grows?

[@DavidHeathHomebrew]

Due to demand that will come in the near future.

[@arnoldovid4675]

Regarding settings the Anton Paar device, which calculations do you use?

[@DavidHeathHomebrew]

I use the standard settings.

[@cindy99toker]

I use the blue box refractometer as a way to check when the mash is completed. When the brix stops increasing, i pull the grains.

[@DavidHeathHomebrew]

That works 🍻🍻🍻

[@seanjennings9042]

Thanks for this video. It's been one I've been looking for a while. As an owner of a small brewery that has just started up I have been relying on a hydrometer to this point as unfortunately the Anton Paar units are out of my budget at this point. I have also been reluctant to purchase the unbranded refractometers over concerns of the very reasons you have shown in your video. I always intend to rely on hydrometers for OG and FG readings anyway but a refractometer will help with taking readings during the sparge. One quick question, were these readings taken with wort correction factor taken into account?

[@DavidHeathHomebrew]

Thanks. I would recommend the Anton paar solutions personally. These tests were completed as was. The saber is tuned to wort and sugar. I have high gravity tests coming next.

[@CascadesHomebrew]

For the cheap model, is the reading from the SG scale? I have followed the advice to use the Brix reading and convert that to SG with a wort correction factor. I use the BeerSmith Mobile app tool for this. Using this method I have found my readings to be within a gravity point of my hydrometer readings. It is an additional step, lets me know on brew day how I am doing. It sounds like the Kegland one has a better SG scale built in. I use a hydrometer reading for my official OG and FG readings. Cheers!

[@DavidHeathHomebrew]

It should not make any difference but my Blue Box only has Brix. Your hydrometer is also unlikely to be very accurate, if its the typical budget type.

[@FermentationAdventures]

Interesting. Additional data points at 1.065 and 1.100 and maybe different SRM wort would be good to know. Would the kegland always off by .001 or by some linear range at 1.1?

[@DavidHeathHomebrew]

Thanks. Yes, I can do more with this. Lets see

[@ianjones6849]

Another great video David. The difference in readings between the cheapest and more expensive is about 4 points. Other than having an affect on the final ABV, will an incorrect gravity reading of the wort have any affect on taste, colour etc? I find it very difficult to read an exact figure on the cheaper ATC as the display is very small, so I'm wondering if its worth the extra outlay?. Thanks, Ian

[@DavidHeathHomebrew]

Cheers Ian. A change in gravity will have an effect on final ABV, balance and taste. The actual difference will vary on the recipe. In terms of value this is really down to the individual but personally I see great value in accuracy.

[@ianjones6849]

Thanks so much for responding and the expert advice. I am struggling to find a Saber supplier in the UK, hopefully there will be availability soon, thanks again @@DavidHeathHomebrew

[@DavidHeathHomebrew]

@ianjones6849 I would suggest contacting Angel homebrew and Brewkegtap to see when they have these coming in. You may be able to reserve one.

[@ianjones6849]

thanks David, great suggestion. I have also reached out to Olbrygging Norway (they have stock) a supplier which you recommended to me a good few years back now! 😀. I bought a bottom filter for my old GF from them. I'm not sure what the current delivery situation is, post Brexit, but will await their response, thanks again and cheers!

[@DavidHeathHomebrew]

@ianjones6849 this is the company that I work for but we do not ship to the public outside of Norway 🍻🍻

[@patrickglaser1560]

That's why I've always been lax about following recipes to the T... maybe it's cause I've only had one dissapointing batch.

[@DavidHeathHomebrew]

People can argue this both ways but I prefer a «live and let live» approach personally.

[@patrickglaser1560]

@@DavidHeathHomebrew how laissez-faire 😉

[@DavidHeathHomebrew]

@patrickglaser1560 Haha, I think there way too many these day telling others that they are «not allowed to» do as they wish with way too many thinks, so yes very much «laissez-faire» 😎🍻

[@pvj2000]

No pictures just encase we have another 'hydrometer gate' scandal! J/K

[@DavidHeathHomebrew]

Haha. I tried and tried, seems impossible.

[@oslodunc]

“ Are you happy with the end result?”

[@DavidHeathHomebrew]

Thats the question to many things in life, as I see it 🍻🍻🍻

[@oslodunc]

I’ve had a couple of brews lately that the numbers were off but turned out great. I’m more relaxed about this these days.

[@DavidHeathHomebrew]

@oslodunc Yes, it is often not the end of the world. Some mistakes can also lead to something grest 🍻🍻🍻

[@gunnarbech]

Didn’t you just assume, that the most expensive was the most accurate? Why?

[@DavidHeathHomebrew]

Its far from an assumption, it is a fact. I covered the specifications of the SmartRef within this video too.

[@bobshiruncle7746]

HI THERE I'M THE PICKY GUY! It's wert as in worst. not wort as in wart. bloody english...

[@DavidHeathHomebrew]

Thanks for your thoughts. Actually, this is not totally correct, I did some research on this some years back. Wert is the old spelling and the way it was pronounced in old English. In modern times this word has become “wort” and it is totally correct to pronounce it either way. I pronounce it the modern way essentially because this was how I just heard it said for many years. Now for some reason some have reverted to the old way. I hear on this from time to time from people and some even get quite annoyed! Oh well 🍻😂😎