Refractometer vs. Hydrometer Video

[aekdbbop]

Ok, I finally got this figured out in BeerSmith, thanks to Brad.

Under Tools > Refractometer > Fermenting Wort:

Input your Brix in the field, then your OG beneath it. That will give you your corrected FG

Sorry If everyone else knew this, but for some reason I made it much more difficult then it should have been...

 

[Bobby_M]

Bobby, what make and model refractometer are you using? Where did you buy it?

The seller on Ebay is Gainexpress

This is the exact item I have:
Brix Refractometer 0-32% w/ LED light Sugar Fruit CNC c - eBay (item 330296354843 end time Dec-30-08 08:50:04 PST)

They even have a cheap digital PH meter for $25.

WATERPROOF DIGITAL PH METER TESTER, Thermometer °C °F f - eBay (item 230315845047 end time Dec-30-08 06:47:57 PST)

 

[Moonshae]

Very nice, Bobby!

 

[DetroitOS]

I like using the hydrometer because I look forward to drinking the sample.

 

[GNBrews]

Ok, I finally got this figured out in BeerSmith, thanks to Brad.

Under Tools > Refractometer > Fermenting Wort:

Input your Brix in the field, then your OG beneath it. That will give you your corrected FG

Sorry If everyone else knew this, but for some reason I made it much more difficult then it should have been...

LOL..didn't I give you the complete path in the other thread. Jeez.

 

[HoppyDaze]

Ive been putting my beer back in the carboy after sampling...will this be a problem if I sanitized really good?

 

[flyangler18]

Ive been putting my beer back in the carboy after sampling...will this be a problem if I sanitized really good?

Don't do that. Drink the sample.

 

[bob1852]

Don't do that. Drink the sample.

or get a refractometer and only use a few drops

 

[aekdbbop]

LOL..didn't I give you the complete path in the other thread. Jeez.

Ha, yeah you did, now that I look back at it..

I just didn't quite understand it until a few hours ago..

 

[HoppyDaze]

Don't do that. Drink the sample.

OK, 10-4, roger that...

 

[cactusgarrett]

This may be a pretty elementary question, but i'm new to using a refract: For pre-fermented wort, once i get the OG, Brix and subsequent correction factor, is this factor constant across every pre-fermented liquid i test, or does the factor apply only to this batch of wort throughout its fermenting life?

 

[Bobby_M]

The OG only applies for that batch.

 

[cactusgarrett]

I mean the correction factor. I ask because the tab in the options menu in Beersmith for "Calibrate Refractometer Settings" (step 2) saves these inputs.

So, being unfamiliar with the refractometer section in Beersmith as well as the refractometer itself, i'm going to have to "calibrate" this Beersmith setting and get a correction factor for each wort?

 

[ArcaneXor]

I mean the correction factor. I ask because the tab in the options menu in Beersmith for "Calibrate Refractometer Settings" (step 2) saves these inputs.

So, being unfamiliar with the refractometer section in Beersmith as well as the refractometer itself, i'm going to have to "calibrate" this Beersmith setting and get a correction factor for each wort?

1.04 is a pretty standard correction factor. What it does it account for the fact that beer isn't just made out of water and sugar, but that there are other components as well that refractometers aren't designed to take into account.

From BYO:

Understanding the Reading

If a sample is simply sucrose and water, you can take a refractometer reading directly. If, however, you are testing wort, which is mostly maltose, you must make a correction that I call wort calibration.

Wort Calibration

Measurements of the specific gravity of wort using a refractometer will not agree with the measurements of gravity using a hydrometer. Brix refractometers are meant to measure the percentage of sugar in a pure sucrose solution. Since wort is not simply sugar and water, you need to make a small correction because of the non-sugar components of the wort. The correction factor is different for different breweries. Beers that are very dark or have a very high starting gravity may also require a different correction factor. To calculate your correction value, measure the specific gravity with your refractometer. Then chill a sample of your wort and measure the gravity with a hydrometer. Convert the hydrometer reading to Brix using the equation: Brix = (SG-1)/0.004. Then divide the reading of the refractometer by your actual hydrometer reading. You should have a number between 1.02 and 1.06. If you do this for several worts and average them, you will get a number that you can use for your brewery. ProMash defaults to 1.04 and this is the number I use. Once you have this number, divide all of your subsequent refractometer readings by your calibration number to get the actual reading. For example, if your reading is 14.6 Brix then your corrected reading is 14.04 Brix (14.6/1.04=14.04). Then, we can convert the measurement in Brix to specific gravity.

 

[cactusgarrett]

If you do this for several worts and average them, you will get a number that you can use for your brewery.

Cool. Thanks for the details - this is specifically what i'm looking for. I was testing out a starter i just made, and came up with a correction of 1.0757 from an OG of 1.033 and 8.9% Brix. I plan on testing each wort from here on out with grav AND Brix to make sure they jibe, but by you mentioning to average serveral worts, this leads me to believe that the correction factor i get resulting from grav to Brix is characteristic of my specific refractometer. Does this seem like an accurate statement?

 

[ArcaneXor]

Cool. Thanks for the details - this is specifically what i'm looking for. I was testing out a starter i just made, and came up with a correction of 1.0757 from an OG of 1.033 and 8.9% Brix. I plan on testing each wort from here on out with grav AND Brix to make sure they jibe, but by you mentioning to average serveral worts, this leads me to believe that the correction factor i get resulting from grav to Brix is characteristic of my specific refractometer. Does this seem like an accurate statement?

I think it's more characteristic of the types of beers you tend to brew, and the averaging procedure also accounts for user-induced error from inconsistent hydrometer readings.
I am not sure, but I would think that the calibration value would be constant between refractometers.

I'll probably be able to comment on this more once I actually receive my own refractometer sometime in the next couple of weeks

 

[southsidebrewer]

I think it's more characteristic of the types of beers you tend to brew, and the averaging procedure also accounts for user-induced error from inconsistent hydrometer readings.
I am not sure, but I would think that the calibration value would be constant between refractometers.

I'll probably be able to comment on this more once I actually receive my own refractometer sometime in the next couple of weeks

probably not a big deal, but i believe the primary intention with this experiment is to calibrate your new refractometer response to your hydrometer (calibration errors with your hydrometer, calibration errors with refractometer, systematic error in the manner in which you interpret hydrometer readings, etc) while taking into account your brewery (typical beer styles you brew, contributions from your equipment, etc). this offset, or "factor", will likely change from refractometer to refractometer (inter and intra model) as no two instruments are ever identical…you’ll probably also find the factor will change if you bring in a new hydrometer into your shop (they’re not all identical either). it’s a good idea to do this once when you get your new refractometer to establish your factor…then periodically verify your factor to account for any drift (bouncing your refractometer on the floor the day after you’ve established your factor may warrant a “verification”, e.g.).

I use an ATAGO PAL-1 model refractometer (given to me) and have been pretty happy with the performance.

 

[ArcaneXor]

OK, got mine today and checked it on my pseudo-Apfelwein OG. It's the RHWN-25/BrixATC:

First sample:

Calibrated Hydrometer after temp correction: 1.057
Calibrated ATC Refractometer: 13.8 Brix

Second sample:

Calibrated Hydrometer after temp correction: 1.059
Calibrated ATC Refractometer: 14.0 Brix

Nearly spot-on!

What is interesting, though, is that Strangebrew Java, the Morebeer spreadsheet and various internet calculators to convert Brix to OG vary by as much as 3 gravity points. Very interesting.

 

[nathan]

I found that my brix reading was off, based on a table I found online for converting brix to specific gravity. Then later I tested my (3rd) hydrometer, and found it was 2 points off in proper temperature distilled water (read 1.002). So now I need to consider getting my FOURTH hydrometer.

My first broke, no surprise there. My second got less accurate over time, till it was 6-7 points off. This one is now 2 points off. It's not points low, which might be explained by hitting the bottom of tubes or something when it's slid into it's case, I cannot explain why the paper inside is somehow riding UP in two hydrometers.

Does anyone sell a stainless hydrometer with gradations etched on it?

I'd like to test my refractometer against an accurate hydrometer for a few sessions before I'm comfortable enough to drop the hydrometer.

 

[PseudoChef]

For any mathematically inclined, I believe this is the correction formula:

SG = 1.001843 - (0.002318474*OB) - (0.000007775*OB*OB) - (0.000000034*OB*OB*OB) + (0.00574*FB) + (0.00003344*FB*FB) + (0.000000086*FB*FB*FB)

SG = actual specific gravity
OB = original Brix
FB = final Brix

 

[bull8042]

I can't find the spreadsheet anywhere. Do you happen to have a link for that somewhere? Bobby, ol' buddy ol' pal....

Never mind, I found it here - http://morebeer.com/learn_vids/vids_refract

 

[nathan]

do they make refractometers that are plato? Or are plato and brix the same?

 

[remilard]

Plato and Brix use different reference temperatures, but they are very similar.

 

[BeerCanuck]

Excellent Video Bobby..I am now convinced it's a needed device vs gadget.
I bought one off ebay
$24 for the refractometer and $20 for shipping...hope it arrives in one piece

Cheers
Steve

 

[Munsoned]

Just bumping this (awesome) thread to ask if anyone that recently bought a refractometer has any follow up they'd like to add--does it work, is it relatively accurate, etc.? Any particular models that are working/not working for folks?

Thanks!

 

[ArcaneXor]

I don't really use mine (RHWN-25/BrixATC) anymore, except for meads. Too much variance between successive readings due to small hop particles, trub, etc.

 

[Bobby_M]

I always use mine during brewing and for taking the OG. I've given up on trying to use it for mid/FG because the correction spreadsheet always seems to be +/- 1.002. I guess if that's "good enough", it's still workable. I would be OK with it but I find that I always want to taste the sample anyway so I've found a smaller volume test tube and a smaller hydrometer so it only takes me 1 ounce. I get my accurate FG and a quick sip of beer.

 

[DeathBrewer]

I would be OK with it but I find that I always want to taste the sample anyway...

Word to that! Smaller hydrometer and sample vessel? Do tell, where did you get this?

 

[Bobby_M]

I got a huge score of brewing materials from a guy on CL and I found it in a box. The tube is like 1/2" x 4" and the hydrometer fits inside. The scale is only 1.000 to 1.040 but I find that it's perfect for FG reading. I had to drill a hole in a block of wood to hold the tube upright because it's a curved glass bottom test tube. No big deal.

 

[DeathBrewer]

Gotcha...I think they make a lot of the "final gravity" hydrometers for winemaking...I'll have to ask what they can order at my LHBS.