Refractometer

[ProfessorWoland]

I was given a refractometer on my birthday yesterday and have been measuring the Brix of nearly every liquid I can find (my cup of tea this morning was just under 2%.)

Anyone know a good idiot's to using one?

 

[Gear101]

I set mine of zero with distilled water and check it every now and then.

 

[ProfessorWoland]

I enjoy using it as I feel like a mad scientist. I'm running out of liquids to test

 

[Culbetron]

My dear professor.

Check out: http://www.homebrewstuff.com/refractometer-how-to

Don't forget to invite me to your ball.

 

[Gear101]

I enjoy using it as I feel like a mad scientist. I'm running out of liquids to test

Try different fruit juices, they are all over the board when it come to Brix. LOL

 

[ProfessorWoland]

My dear professor.

Check out: http://www.homebrewstuff.com/refractometer-how-to

Don't forget to invite me to your ball.

I'm glad someone got my username

 

[Culbetron]

I live in Russia. I'm contractually obligated to get all Russian literature references.

Have fun with that refractometer. It's on my wish list!

 

[jwalker1140]

I've been using one for several years now. My advice: calibrate it every day you use it. And my tap water gives me the exact same reading as distilled water so that's what I use.

 

[BansheeRider]

My refractometer was all over the place during my last brew. I knew my brew would be very high in OG so when I read 1056 I knew that was wrong. Then I tested again and it read 1086, much better. I tested one more time before pitching yeast and it read 1035. I calibrated before use and I was getting 3 different readings with 3 different samples. Not sure if these are aways 100% accurate. I ended up just using my hydrometer to get an OG before pitching yeast. The hydro read 1086 so I tested with my refractometer again and it said 1086. Not sure what was going on with my refractometer. This was only the second time I've used it so it's still a brand new piece of equipment.

 

[ProfessorWoland]

My brother has given me another one which has a v/v scale. I'm just going to start researching that.

 

[william_shakes_beer]

My refractometer was all over the place during my last brew. I knew my brew would be very high in OG so when I read 1056 I knew that was wrong. Then I tested again and it read 1086, much better. I tested one more time before pitching yeast and it read 1035. I calibrated before use and I was getting 3 different readings with 3 different samples. Not sure if these are aways 100% accurate. I ended up just using my hydrometer to get an OG before pitching yeast. The hydro read 1086 so I tested with my refractometer again and it said 1086. Not sure what was going on with my refractometer. This was only the second time I've used it so it's still a brand new piece of equipment.

If the wort is cloudy the line in the eyepeice is less than sharp. Try to get the clearest sample possible. I usually press a teaspoon into the top of the mash tun (after stirring like a fiend) and take my sample from that.

 

[ajdelange]

(my cup of tea this morning was just under 2%.)

Did your cup have 4.7 grams of sugar in it (about 1 tsp)? If it did then you got a reasonably accurate reading. If you drink your tea black then your reading is way off.

People need to understand that refractometers are calibrated to read grams of sucrose per 100 grams of solution where the solution contains sucrose and water and nothing else. Readings taken on wort are often close to the actual extract readings for that wort and this has lulled many brewers into thinking a refractometer is a replacement for a hydrometer. The problem is that refractometer readings on wort are often in error by 1-2 Bx as wort isn't a mixture of sucrose and pure water.

Refractometers can be used to advantage in the brewery to measure the alcohol content of beer if they have first been calibrated for that beer against a densitometer or Alcolyzer (but if you have the Alcolyzer why would you bother with a refractometer?). Without that calibration they are pretty useless, IMO. For OG measurment I strongly encourage comparison to hydrometer readings until it is established that the refractometer's error is aceptable. If the two agree closely for all your Pilsners, for example, then you can use the refractometer for Pilsners in the future but if you brew something new (say a Weizenbock) then be sure to compare until you are confident that the agreement is good enough for Weizenbock. Note that I am not singling out Weizenbock as a beer for which the agreement is poor nor Pilsner as one where it is good. Just arbitrarily picked these two as examples of two rather different beers.

 

[william_shakes_beer]

Did your cup have 4.7 grams of sugar in it (about 1 tsp)? If it did then you got a reasonably accurate reading. If you drink your tea black then your reading is way off.

People need to understand that refractometers are calibrated to read grams of sucrose per 100 grams of solution where the solution contains sucrose and water and nothing else. Readings taken on wort are often close to the actual extract readings for that wort and this has lulled many brewers into thinking a refractometer is a replacement for a hydrometer. The problem is that refractometer readings on wort are often in error by 1-2 Bx as wort isn't a mixture of sucrose and pure water.

Refractometers can be used to advantage in the brewery to measure the alcohol content of beer if they have first been calibrated for that beer against a densitometer or Alcolyzer (but if you have the Alcolyzer why would you bother with a refractometer?). Without that calibration they are pretty useless, IMO. For OG measurment I strongly encourage comparison to hydrometer readings until it is established that the refractometer's error is aceptable. If the two agree closely for all your Pilsners, for example, then you can use the refractometer for Pilsners in the future but if you brew something new (say a Weizenbock) then be sure to compare until you are confident that the agreement is good enough for Weizenbock. Note that I am not singling out Weizenbock as a beer for which the agreement is poor nor Pilsner as one where it is good. Just arbitrarily picked these two as examples of two rather different beers.

There are refractometers for many substances. Beer, wine, saline solution, and even urine!!! I would assume that a refractometer specifically built for beer would be quite accurate for all classes of beer. Is the difference between the refraction index for different a dark and a light beer really so extreme as to be non usable? I am not a scientist, so I genuinely appreciate the input from those who are more familiar with the field.

 

[ProfessorWoland]

Did your cup have 4.7 grams of sugar in it (about 1 tsp)? If it did then you got a reasonably accurate reading. If you drink your tea black then your reading is way off.

No sugar and a dash of milk (the proper way to drink tea!)

 

[ProfessorWoland]

I've not been able to find any info on using the refractometer with the v/v scale.

Help anyone?

 

[ajdelange]

There are refractometers for many substances. Beer, wine, saline solution, and even urine!!!

Since urine is essentially used beer I will point out that there are separate refractometers for people pee and pooch pee.

I would assume that a refractometer specifically built for beer would be quite accurate for all classes of beer.

No, the whole purpose of the MOA is to calibrate the refractometer against the type of beer. Thus a brewery would have a calibration for its Pilsners and another for its ales.

 

[fartinmartin]

The site below has really helped me with my refractometer

http://www.musther.net/vinocalc.html

 

[gr8shandini]

My refractometer was all over the place during my last brew. I knew my brew would be very high in OG so when I read 1056 I knew that was wrong. Then I tested again and it read 1086, much better. I tested one more time before pitching yeast and it read 1035. I calibrated before use and I was getting 3 different readings with 3 different samples. Not sure if these are aways 100% accurate. I ended up just using my hydrometer to get an OG before pitching yeast. The hydro read 1086 so I tested with my refractometer again and it said 1086. Not sure what was going on with my refractometer. This was only the second time I've used it so it's still a brand new piece of equipment.

How were you cleaning between samples? The ATC on a refractometer corrects for the temperature of the head of the instrument, but only within a certain range. If you're rinsing with very hot or very cold water, it could temporarily screw things up. Similarly, if you're testing hot wort, it can take a minute for everything to equalize. You can often even see the line moving.

As for the correction factor referenced above, here's my take on it: It all depends on how anal you want to be. Most of my brews are 1.050, give or take a couple of points. Applying the "standard" correction factor of 1.04 only changes that by about 2 points. I honestly can't tell the difference between a 1.048 beer and a 1.050 one, so it's kind of an academic difference.

Furthermore, if my actual correction factor for a stout were, say, 1.051 and a Pilsner 1.036, the distinction between the two is even more "in the noise", so it really doesn't make sense for me to keep track of a correction factor for every style of beer I brew. Now, if I were brewing really big beers, this may become more of a factor. But I think consistency is more important than the absolute numbers for most of us. If I brew a recipe that comes out to 1.046 every single time even though I think the gravity is 1.048, that's better than if I can measure the SG to 1.00001 but it varies by +/-0.007 every time.

 

[PRE66_6TART]

I just ordered my refractometer before stumbling across this thread. Now I'm wondering if I wasted my money. I've never heard that they needed to be calibrated for different beers styles. I'm a little lost on the details though. What is the margin of error we are talking about? I only brew ales if that makes a difference.

 

[kh54s10]

I just ordered my refractometer before stumbling across this thread. Now I'm wondering if I wasted my money. I've never heard that they needed to be calibrated for different beers styles. I'm a little lost on the details though. What is the margin of error we are talking about? I only brew ales if that makes a difference.

f

I think this is wrong. I also have never heard this before. Unless you get a refractometer that cannot read the full range of beer gravities.

You need to calibrate before you start so that it reads 1.000 with distilled water. If it is not calibrated then you might start at something like 1.016 then every reading you take will be high by .016

On the other hand refractometers cannot read accurately with the presence of alcohol. If you take a reading after fermentation has started you will have to make a correction. There are online calculators to do this.

 

[ajdelange]

I think there is some misunderstanding here. It is when a refractometer is used to measure ABV that it needs to be calibrated for the family of beers. If you have a lab with a densitometer or pycnometer but don't want to have to do all that work for each gyle you come up with a calibration curve for each beer in the profile an can, using that, quickly estimate ABV, in the cellar, on each batch. Of course a modern lab isn't equipped with a densitometer. It is equipped with an Alcolyzer. Just put a sample bottle with a few mL in the carousel and ABV, TE, OG, ADF, RDF, AE... are all sent to your computer.

The problem with the use of refractometers WRT wort is that most of the time they read within 1 °P. But sometimes they are in error by more than 1, as much a 2 Bx or even more (an example would be the gent who read 2.6 on his tea with no sugar in it) and the only way to know is by checking against a hydrometer and if you do that then what's the point in having the refractometer? But if you are OK with potential error of 1 Bx most of the time and occasionally being off by more than that, a refractometer may be fine for you.

 

[ProfessorWoland]

Anyone got any info on how to use the ones with a v/v scale yet?

 

[stpug]

I have had a wonderful experience with my refractometer, and have personally found the final gravity point difference between my refractometer and my hydrometer to be minimal, acceptable, and well within the range of error of reading my hydrometer. I have been collecting comparative data on FG sample readings so I can have a clearer idea of the range of error I might be looking at when using a refractometer to determine FG. With one exception, I have found the FG point difference to be <=1 gravity point (e.g. 1.015 vs 1.014), and frequently I've seen 0-0.5 point differences. I've posted this elsewhere but I have since added a few data points.

                   | DH20   | ESB     | RedAle  | BelgPA | CalComB | SWinSai | SSumSai | BGoldStr | CrmAle  | BDarkStr | BelgIPA | VnaLgr
-------------------|--------|---------|---------|--------|---------|---------|---------|----------|---------|----------|---------|-------
Sample temp        | 60.0   | 59.7    | 59.9    | 60.3   | 60.1    | 59.7    | 59.8    | 72.5     | 66      | 71.8     | 60.3    | 60.2
OG (Brix)          | 0      | 14.6    | 13.75   | 14.2   | 13      | 18.4    | 14.5    | 18.6     | 12      | 22.5     | 16.1    | 14.2
OG (SG)            | 0      | 1.058   | 1.054   | 1.056  | 1.051   | 1.074   | 1.058   | 1.075    | 1.047   | 1.092    | 1.064   | 1.056
FG (Brix)          | 0      | 8.0     | 6.6     | 7.0    | 6.95    | 8.4     | 6.6     | 7.8      | 6.1     | 11.0     | 7.8     | 7.2
FG (Beersmith)     | 0      | 1.015   | 1.009   | 1.010  | 1.013   | 1.008   | 1.006   | 1.004    | 1.010   | 1.014    | 1.010   | 1.012
FG (Hydrometer)    | 1.0000 | 1.0145  | 1.0105  | 1.0100 | 1.0125  | 1.0090  | 1.0070  | 1.0040   | 1.0105  | 1.0150   | 1.0100  | 1.0120
Gravity Difference |        | 0.5     | 1.5     | 0      | 0.5     | 1       | 1       | 0        | 0.5     | 1        | 0       | 0

I believe that the precision of your reading is very important when using a refractometer for both the OG and FG, and taking the reading from the top of the fuzzy line is equally important. The lines can be VERY close in a refractometer and account for 0.2 Brix difference in readings, and I make every attempt to get my reading down to the [mid-point] hundredths decimal place. Some things I do is make sure to let the line become clear and distinct; wait a minute or two to ensure identical readings; and turn the refractometer upside-down to get greater contrast.

I'll continue to take comparative readings over time and will keep adding data points to my dataset, but I don't worry much about my corrected FG readings that I obtain from beersmith. BTW, I have found much closer and more frequent corresponce between corrected readings using BeerSmiths refractometer tool versus Sean Terrills.

When using a refractometer, the line can be quite fuzzy at times. I have found the best place to obtain the readings is from the top of the fuzzy line as shown in this example:

 

[gr8shandini]

Hmm. I never thought to turn the refractometer over to make it easier to read. I'll have to give that a try next time.

Also, minor nitpick, but I think you meant to say that each small line is 0.2 Brix. If it was 2, it'd be so hard to read as to be almost useless.

 

[stpug]

Hmm. I never thought to turn the refractometer over to make it easier to read. I'll have to give that a try next time.

Also, minor nitpick, but I think you meant to say that each small line is 0.2 Brix. If it was 2, it'd be so hard to read as to be almost useless.

Good catch!! I did mean 0.2 brix

 

[Clonefan94]

I just ordered my refractometer before stumbling across this thread. Now I'm wondering if I wasted my money. I've never heard that they needed to be calibrated for different beers styles. I'm a little lost on the details though. What is the margin of error we are talking about? I only brew ales if that makes a difference.

I read this on Friday, but was brewing today, so, I decided to hold off on my response until today. I have checked my refractometer now 3 times against my hydrometer. All 3 times it has been spot on. It had been a while since I checked it and the other two times were against fairly light colored wort. Today I was brewing an IPA that was a bit darker on the scale and wanted to check it on that. Again, spot on.

Now, I don't use it for FG, Just pre-boil, OG and tests during the boil to make sure I'm going to be hitting my numbers. I always calibrate it with distilled water, then leave it on the counter in my kitchen, where I calibrated it. LIving in the midwest, it's not uncommon to have good sized temperature swings outside during the brew, so I always just put a little in a cup and then set it on counter to adjust to the calibrated temp. So, mine, an inexpensive one at that, seems to work great.

As I said though, I don't use it for FG readings. Seems that's where the real variations start. Personally though, I like to use the Hydro sample for FG as a taste test, to make sure everything is coming together correctly.