# Refractometer usage



## Matplat (23/8/16)

Evening all, 

I did a bit of a search on this, but could only find about people who hadn't used a calculator to correct their FG reading.

So i just got a refractometer, and immediately calibrated it. Being most of the way through my current fermentation, i thought I would give it a go.

First thing i noticed was that whereas when calibrating with water the line was perfectly defined, it was now much more blurry. I assume this is due to cloudiness from suspended yeast?

I converted my original gravity reading to brix (10.5) so I could use a calculator, using my approximate blurry FG reading of 5 brix, I get an FG of 1.006 however this does not match my hydrometer reading of 1.010?

Where am I going wrong?

Cheers, Matt


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## Ducatiboy stu (23/8/16)

Honestly........

Refractometer suck. Sorry, but they do. I made the mistake of buying one in the big refractometer rush of 2000 & something. They are a bit of a wank

*First thing i noticed was that whereas when calibrating with water the line was perfectly defined, it was now much more blurry. I assume this is due to cloudiness from suspended yeast?*

Stick with a Hydro. B)

My kids ended up using it to amuse themselves with the flappy bit at the end....and using it as a bit of a thing to look at small objects with.


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## Denobrew (23/8/16)

Hey Matplat, have you tried turning the eyeglass to focus it? You probably have, not trying to be a smarty pants. Cheers Tim


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## mckenry (23/8/16)

Yeah, theyre a pain in the arse. I have one thats retired. But the answer to your question is that they are not for measuring samples that contain alcohol, unless you have the correction factor.


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## gaijin (23/8/16)

I've plugged your numbers into the formula I use and 1.006 seems to be correct. Not sure why the hydrometer reading is high - was there perhaps a few tiny bubbles in the lens of the refractometer making the fluid seem appear thinner/give a lower reading? Maybe try taking another reading as this has happened to me before.


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## Danscraftbeer (23/8/16)

Refractometer used only for pre ferment readings.
I use my _calibrated _refractometer as a quick easy gravity reading any time through the brew process. Then the final confirmation measurement against my Hydrometer for the opening gravity reading.


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## mikec (23/8/16)

Clear sample and good light will help with readability. You do need to use a calculator to compensate for the alcohol factor but it sounds like you are doing that.


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## Ducatiboy stu (23/8/16)

mikec said:


> Clear sample and good light will help with readability. *You do need to use a calculator to compensate for the alcohol factor *but it sounds like you are doing that.


And that bit as well that makes them more of a PITFA


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## MichaelM (23/8/16)

There is a correction factor that needs to be determined for your refractometer. This is done by taking numerous readings for unfermented wort with the refractometer and hydrometer and plugging them into a spreadsheet. This may be why you got a reading of 1.006 compared to a hydrometer reading of 1.010. Brewersfriend website has a spreadsheet for doing this.


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## Ducatiboy stu (23/8/16)

MichaelM said:


> There is a correction factor that needs to be determined for your refractometer. This is done by taking numerous readings for unfermented wort with the refractometer and hydrometer and plugging them into a spreadsheet. This may be why you got a reading of 1.006 compared to a hydrometer reading of 1.010. Brewersfriend website has a spreadsheet for doing this.


Can we have that in English please

At least the old Hydro has easy to read markings that are easy to read


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## MichaelM (23/8/16)

Ducatiboy stu said:


> Can we have that in English please
> 
> At least the old Hydro has easy to read markings that are easy to read


not saying that refractometer is better. Just giving a reason for the discrepancy. At least a hydrometer is more straight forward to use.


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## stewy (23/8/16)

Refractomoters are great to use after the mash, during boil etc. Once the beer begins fermenting use your hydro


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## Bribie G (23/8/16)

I have no problem at all with my refrac, used during the boil or before pitching. After that let hydro be your friend.

ed: when I lived on Bribie Island a pineapple farmer (such people are the main users of refracs to measure sugar content, you don't seriously think in a million years that they actually manufacture such devices for the sole use of home brewers, ffs?) had a look at mine and said it's good. The ones with OG scale are a very very small subset of the refracs out there, and they are aimed at home brewers but are just bog standard fruit juice ones.


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## btrots87 (23/8/16)

I only ever use my hydrometer at two points these days, getting an OG just before pitching and confirming the FG once I'm sure the ferment is finished. All other readings I just use the refractometer and plug the numbers into Brewer's Friend which converts it to a gravity reading.

I agree the hydrometer can be a bit easier to read and is potentially more accurate, which is why I use it for the OG and FG readings, but the refractometer has other advantages. It uses a lot less sample which means less beer wasted, and you don't have to worry about cooling a couple hundred mL of sample to get a reading during the mash/boil. I find it really helpful to use to keep an eye on my ferment gravity and getting mash/boil gravities to track efficiency.

For what it's worth I always find that my hydrometer readings and corrected refractometer values are within 1-2 points of each other anyway, even after the ferment. The Brewer's Friend calculator seems to be pretty reliable.


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## Lyrebird_Cycles (23/8/16)

The refractometer measures the refractive index of the solution.

Refractive index is a colligative property: it depends on the number of solute molecules present*, not on their properties such as molecular weight.

Density is not a colligative property: it is highly dependent on the weight of the solute molecules present.

Therefore the equivalence between refractive index and density changes when the type of molecules in solution changes.

A standard brix refractometer converts the refractive index to the equivalent sucrose solution in weight %.

Since wort solids are not sucrose, a correction factor must be applied which is dependent on the average molecular weight of the wort solids as compared to sucrose.

The average molecular weight of your wort solids depends on the mash profile and the types of malts and adjuncts used so it will vary for each brew.

A good average factor is about 4% eg on an average wort if a densitometer reads 12.5 Brix (or Plato) a refractometer will read about 13.0.

During ferment two things happen that affect the reading: one is the production of alcohol which breaks the rules for solutes and increases the refractive index.

The other is that the yeast uses up the low molecular weight sugars first so the average molecular weight of the remaining wort solids keeps increasing, thus changing the relationship between density and refractive index further.

The calculators commonly used account for the first of these effects but not the second, so they are to be taken with a grain of salt.

Despite this, with a bit of practice you can use a refrac during ferment and get quite good results. You'd just better like maths is all.



* This is on the assumption that the solute molecules themselves do not affect refractive index. This is the case for most solids but it is not the case for dissolved liquids such as ethanol.


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## Blind Dog (23/8/16)

^^^^

Or what DBS said in English...


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## Lyrebird_Cycles (24/8/16)

Matplat said:


> I converted my original gravity reading to brix (10.5) so I could use a calculator, using my approximate blurry FG reading of 5 brix, I get an FG of 1.006 however this does not match my hydrometer reading of 1.010?
> 
> Where am I going wrong?


Further to post #15 above, from the best information I can find, the numbers you gave are possible if the average MW of the remaining wort solids corresponds to that of saccharides with a mean degree of polymerisation of about 3.5.

I'm guessing from that figure that we are talking about a wort produced from a highish temperature mash (>66 oC)


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## Matplat (24/8/16)

So many responses! I pretty much went to bed after posting this... guess I'm turning into a lightweight. I bought the refrac so I could monitor gravity during the mash, monitor gravity of the runnings and so that smaller FG samples needed to be taken. Seems like I will just drop the last one, which isn't such a bad thing because I like tasting the samples anyway.
Lyrebird, you continue to impress me with your understanding and knowledge of the process. This wort was mashed between 63-64, however I'm wondering if something isnt right though because I was expecting FG below 1.010 for that mash temp.


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## droid (24/8/16)

Come on Stu - refractometers are awesome and much easier to use than hydro for taking BG and OG Gravities. Then like others have said - it's over to the hydro once the yeast is involved.

Take a reading when your 80% full during filling your kettle - you can see how your gravity and of course efficiency is doing. Then at 90%. Much better to be getting the OG exactly where you want it (at least you've made a calculation) than to wait till your filling a fermenter. Measuring your BG then at full boil volume based on your (80% - 90% kettle volume ~ whenever you measure) findings. If you get a better eff you can run some more wort in and alter your hops quantities accordingly.

I got 100ltrs more beer on a commercial system because I ran up to the kettle and did a BG - it was 3 or 4 points higher so we put in an extra 100ltrs and hit the OG exactly, there is no reason to not be doing the same at home.


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## Mardoo (24/8/16)

They'll never get my refractometer until they pry it from my cold, dead hands. Unless of course I'm doing sugar additions during ferment. Well that's a completely different story. 

But, yes, you are relying on relative mathematical extrapolation when you use a refractometer. And on the little piece of paper inside the tube staying in one place when using a hydro. 

There's a thread with a massive debate about whether to use the top or bottom of the blurry line to take your refractometer reading. I myself am not seeking absolute precision.

Edit: But you need to get a good one if you get a refractometer. Not worth going cheap, IMO.


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## droid (24/8/16)

@Matplat

My advice on cleaning your refractometer is to NOT use paper towel. Paper towel scratches. Use some soft chux wipes soaked in water to remove the last test solution and then use soft glass cleaner fabric or polishing cloth - stuff that wont scratch.


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## RdeVjun (24/8/16)

As is related elsewhere, the refractometer probably not that much use for a reliable FG or SG during the ferment, although the ABV correction can be helpful for some. Seeing as you have a hydrometer then use that for the ferment, while you should find the refractometer extremely useful for monitoring SG through the mash and boil processes.
One tip I can give you is that tiny air bubbles in the sample can contribute to blurriness, minimise that and you should get a slightly clearer result. Also, focussing is a feature of most, simply rotate the eyepiece.

Any suggestion that the refractometer is a universal device for measuring specific gravity in the home brewing setting is mistaken, sadly disappointment will be the inevitable result. It is a brilliant device in certain circumstances, worthless in others, while exactly the same can be said for the hydrometer, they do complement each other though so I recommend keeping and using both.


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## Lyrebird_Cycles (24/8/16)

Matplat said:


> So many responses! I pretty much went to bed after posting this... guess I'm turning into a lightweight. I bought the refrac so I could monitor gravity during the mash, monitor gravity of the runnings and so that smaller FG samples needed to be taken. Seems like I will just drop the last one, which isn't such a bad thing because I like tasting the samples anyway.
> Lyrebird, you continue to impress me with your understanding and knowledge of the process. This wort was mashed between 63-64, however I'm wondering if something isnt right though because I was expecting FG below 1.010 for that mash temp.


I use a refrac for fermentation monitoring and get perfectly good results. It's a total internal reflection type, not a transmission type, which makes things a little easier and I apply a correction for later readings as above.

Thanks for the compliment: as I have said before, I have a brain made of flypaper, all kinds of shit sticks to it.


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## Bribie G (24/8/16)

droid said:


> @Matplat
> 
> My advice on cleaning your refractometer is to NOT use paper towel. Paper towel scratches. Use some soft chux wipes soaked in water to remove the last test solution and then use soft glass cleaner fabric or polishing cloth - stuff that wont scratch.


I lick mine then wipe it with a clean T shirt, preferably the one I'm wearing. Tastes nice. :icon_drool2:

As droid says the refrac is great measuring OG in the kettle. I often adjust during the boil (edit, add more liquor or conversely boil a tad longer) to get the refrac reading spot on with what Brewmate says it should be. Particularly for comp beers where the ultimate difference between say 4.3% ABV and 4.7% ABV and equivalent variations in IBU from the bittering additions can kick it off-style to a gun judge.


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## Mardoo (24/8/16)

Lyrebird_Cycles said:


> I have a brain made of flypaper, all kinds of shit sticks to it.





Bribie G said:


> I lick mine then wipe it with a clean T shirt, preferably the one I'm wearing. Tastes nice.


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## Matplat (24/8/16)

Pretty sure I have been using baby wipes so far, those things are like WD-40  however it did come with a glass cleaning cloth so guess I'll use that in future. 
It seems that gravity measurement will be a joint effort from now on.... looking forward to controlling my process better. Until now my first gravity measurement has been at pitching, so always been a 'fingers crossed' moment at that point


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## Ducatiboy stu (24/8/16)

A kitten is the ideal thing to clean your refractometer with... bet you didnt know that


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## TheWiggman (24/8/16)

Lyrebird_Cycles said:


> I use a refrac for fermentation monitoring and get perfectly good results. It's a total internal reflection type...


Blurb on web site: "Everyone is talking about the new "Pocket" as featured on recent TV programs and Magazines."






They sure are. I was at a family gathering on the weekend and my sister in law was complaining how she wasn't able to do refrac measurements when walking her dogs and how inconvenient it was that her refractometer didn't fit in her pocket. My brother in law chimed in about the Pocket refractometer and how it was all the rage, and cousins said they'd seen it on TV. We then talked about refractometer portability and convenience to take SG readings running errands, doing the laundry, playing tennis you name it. One of the kids mentioned how styling it was in a magazine they'd read. EVERYONE'S talking about it!
/end overdonesarcasm (BS advertising shits me)


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## Lyrebird_Cycles (24/8/16)

You didn't know that a pocket pal is the latest hipster fashion accessory? Shame on you.


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## Matplat (24/8/16)

Ducatiboy stu said:


> A kitten is the ideal thing to clean your refractometer with... bet you didnt know that


Bummer, I'm all out of kittens since I stopped using an airlock...


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## Tex N Oz (24/8/16)

I've used this calculator and it's never missed a beat. Tested against my hydrometer it seems to be right on the money.

http://seanterrill.com/2012/01/06/refractometer-calculator/


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## Lyrebird_Cycles (24/8/16)

Another thing nobody's mentioned is that refractometers are only accurate when used with a monochromatic light source, classically the D line of a sodium vapour lamp (589 nm). An amber / yellow LED is a close approximation.


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## MHB (24/8/16)

Generally the clearer (less chunky bits floating around) the cleaner the line. One easy way to "filter' the sample is to throw in a cotton ball or a bit of scrunched tissue and suck your sample up through the cotton/tissue with the plastic pipet that should come with every refractometer.
Mark


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## Ducatiboy stu (24/8/16)

Matplat said:


> Bummer, I'm all out of kittens since I stopped using an airlock...


You might get away with a rice gull


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## mikec (24/8/16)

I use an el-cheapo refracto almost exclusively.
Much smaller sample size, faster result.

Also, when you just want to know if the beer has finished fermenting, you don't need a super accurate result. You just wanna know if it's still dropping.
Use a hydro for the final reading if you must.


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## mikec (24/8/16)

Lyrebird_Cycles said:


> I use a refrac for fermentation monitoring and get perfectly good results. It's a total internal reflection type, not a transmission type, which makes things a little easier and I apply a correction for later readings as above.


That looks pretty good. ATC up to 100 deg is awesome.
How much did it set you back?


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## Killer Brew (24/8/16)

Lyrebird_Cycles said:


> Another thing nobody's mentioned is that refractometers are only accurate when used with a monochromatic light source, classically the D line of a sodium vapour lamp (589 nm). An amber / yellow LED is a close approximation.


Yep, can't believe nobody has mentioned that


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## evoo4u (24/8/16)

How does natural daylight fit in with that?


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## Killer Brew (24/8/16)

mikec said:


> I use an el-cheapo refracto almost exclusively.
> Much smaller sample size, faster result.
> 
> Also, when you just want to know if the beer has finished fermenting, you don't need a super accurate result. You just wanna know if it's still dropping.
> Use a hydro for the final reading if you must.


Me too. Use mine for taking readings throughout the mash and boil before doing a hydro test before sending to fermenter to confirm. Likewise I find it more convenient and less wastage to take daily refrac readings to track fermentation (accurate enough with correction applied in my eyes) before taking a final hydro reading once ferment has finalised. I use this correction sheet as I'm old school and like having paper in my brewhouse. 

View attachment Refractometer_Chart___During_Fermentation___Brix_to_SG.pdf


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## Droopy Brew (24/8/16)

Mate it is very easy- no need for spreadsheets etc just use this and punch in your numbers:

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

So you had a SG of 10.5 and FG of 5. Put those numbers into here and voila- 10.042 SG and FG 1.010. same as your refractometer.

edit- use part 2. First part gives SG in Plato, 2nd part gives you your alcohol adjusted reading.


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## malt junkie (24/8/16)

Just get a mass-spectrometer and be done with it!!?!


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## Lyrebird_Cycles (24/8/16)

evoo4u said:


> How does natural daylight fit in with that?


Broadens the border as the different wavelengths refract at different angles (that's how a prism makes a spectrum).


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## Lyrebird_Cycles (24/8/16)

malt junkie said:


> Just get a mass-spectrometer and be done with it!!?!


Don't laugh, I came very close to scoring a Hewlett Packard GC-MS package on Ebay a few years ago for under $7k. Probably a good thing I missed out, would very likely have been a source of domestic disharmony.


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## Ducatiboy stu (24/8/16)

malt junkie said:


> Just get a mass-spectrometer and be done with it!!?!


Bulk buy !


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## Bribie G (24/8/16)

Lyrebird_Cycles said:


> Another thing nobody's mentioned is that refractometers are only accurate when used with a monochromatic light source, classically the D line of a sodium vapour lamp (589 nm). An amber / yellow LED is a close approximation.


That's why I'm thinking of moving back to the UK where sodium street lights are almost universal. When I was a kid I always thought that streets were _meant _to be yellow after dark.


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## Midnight Brew (24/8/16)

BrixCalc is a great free app for refractometer readings. Advantage being on your phone is you'll usually have your phone in your pocket when you're doing brewing tasks in the garage.


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## Lyrebird_Cycles (24/8/16)

mikec said:


> That looks pretty good. ATC up to 100 deg is awesome.
> How much did it set you back?


I bought mine years ago, the price has come down since. They are now a little over $300 on epay.


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## Lyrebird_Cycles (25/8/16)

Droopy Brew said:


> Mate it is very easy- no need for spreadsheets etc just use this and punch in your numbers:
> 
> http://www.brewersfriend.com/refractometer-calculator/
> 
> ...


I think that would only be the case if the 10.5 was the refactometer reading pre correction.

Matplat, correct me if I'm wrong but my reading of the original post is that the 10.5 was the actual OG (hydrometer reading).


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## pcmfisher (25/8/16)

I just wait for the airlock to stop bubbling......


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## Matplat (25/8/16)

Lyrebird_Cycles said:


> I think that would only be the case if the 10.5 was the refactometer reading pre correction.
> 
> Matplat, correct me if I'm wrong but my reading of the original post is that the 10.5 was the actual OG (hydrometer reading).


Yep that's correct, I converted backwards in order to use a calculator.

I missed droopy brews original post though, and I am somewhat confused as to why that calculator gives the 1.010 FG, even applying the 4% correction it gives 1.009 which doesn't follow my original calculation...?


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## Mardoo (25/8/16)

pcmfisher said:


> I just wait for the kitten to stop meowing......


FTFY


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## Ducatiboy stu (25/8/16)

Bloody kittens...they keep you awake at night


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## Droopy Brew (25/8/16)

Matplat said:


> Yep that's correct, I converted backwards in order to use a calculator.
> 
> I missed droopy brews original post though, and I am somewhat confused as to why that calculator gives the 1.010 FG, even applying the 4% correction it gives 1.009 which doesn't follow my original calculation...?


OK so the 10.5 was with a correction factor? If you have used that tool with the correction factor for both and you are 1 pt away from your hydro reading that is pretty close. I've always found the tool to be pretty spot on when I compare refrac and hydro.


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## Matplat (25/8/16)

Yeah, if I had used that calc instead of the one on my phone, I wouldn't have started this thread... 

But then DBS wouldn't have got his kitten fix, so all is not lost.


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## Ducatiboy stu (25/8/16)

Matplat said:


> But then DBS wouldn't have got his kitten fix, so all is not lost.


I am more of a Rice Gulls man


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## barls (25/8/16)

Ducatiboy stu said:


> Bulk buy !


wheres yob?


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## Matplat (28/8/16)

Well, I am unimpressed to say the least. Did a brew last night and monitored gravity along the way, or attempted to at least. It was almost impossible to remove all the air bubbles from the sight glass, which I'm guessing affected readings fairly well.

I was monitoring the last runnings from the malt pipe, and the gravity seemed to be dropping, but then it jumped up at the end??? Then i measured the pre and post boil SG, 1.043 and 1.050 respectively. Double check the OG with the hydro, 1.044.... can't trust the measurements at all so it's basically useless.

How do bubbles affect the reading? I would have thought they would make it lower than actual? Should have checked for myself last night...


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## Ducatiboy stu (28/8/16)

Ducatiboy stu said:


> Honestly........
> 
> Refractometer suck. Sorry, but they do. I made the mistake of buying one in the big refractometer rush of 2000 & something. They are a bit of a wank
> 
> ...


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## nala (28/8/16)

Matplat said:


> Well, I am unimpressed to say the least. Did a brew last night and monitored gravity along the way, or attempted to at least. It was almost impossible to remove all the air bubbles from the sight glass, which I'm guessing affected readings fairly well.
> I was monitoring the last runnings from the malt pipe, and the gravity seemed to be dropping, but then it jumped up at the end??? Then i measured the pre and post boil SG, 1.043 and 1.050 respectively. Double check the OG with the hydro, 1.044.... can't trust the measurements at all so it's basically useless.
> How do bubbles affect the reading? I would have thought they would make it lower than actual? Should have checked for myself last night...


Old saying... poor workman blame tools.


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## Matplat (28/8/16)

Nothing wrong with the workmanship, I made a delicious wort that is happily fermenting away right now. 

The information provided by this tool was unreliable is all I'm saying.


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## Black n Tan (28/8/16)

nala said:


> Old saying... poor workman blame tools.


Not sure that saying is apt in this situation. If you have something helpful to add please do.


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## Killer Brew (28/8/16)

Think I might park mine between brew days. Am finding the converted calcs very unreliable. Just finished tracking the ferment of a pale ale calibrating before every reading. Final one was 6P degrees after starting at 13P degrees (cross checked with hydrometer). The converter suggests that this is a FG of 1007. Hydrometer check is showing 1013. Double checked both to make sure. Hell of a difference.


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## Lyrebird_Cycles (28/8/16)

Using the right calculation will give you the right result.

If you use the Brewer's Friend calculator and put in a correction factor appropriate for attenuated wort (0.90) it gives an equivalent FG of 3.35 oP (1013).

I explained in #15 above why the correction factor changes with attenuation.


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## RdeVjun (29/8/16)

Maltplat, IMO the tiny air bubbles in your refractometer sample don't seem to interfere with the actual result, however they do seem to lead to some blurriness in the blue edge which makes it difficult to instantly note the result.
With respect to the variability, a cooled hydrometer sample at these points would have been be helpful- I'm not convinced the wort draining from the lautering operation is completely homogeneous and, for what ever reason a sharp rise in SG toward the end is not uncommon in my experience, so what you measured may in fact be real.
I personally find that the two instruments complement each other brilliantly, its hard to see what the fuss is all about.


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## Mardoo (29/8/16)

I'd agree. Granted, a refractometer is not a sonic screwdriver, but it's also not like the last few generations of brewers, winemakers, beekeepers and mechanics (among others) have been using the wrong tool and just didn't know it. 

If there's one thing I've learned from brewing, it's that certainty can be a process of estimation. And sometimes, our estimations don't fit reality. It's a weird feeling when I get a reading that makes no sense, but tracking back through the processes usually yields an explanation. 

And thanks, RdeVjun, for that one. You've got me thinking more about weird readings. They're not always operator error.

However sometimes they are device error. That's why I believe bodging together brewing systems can be just fine, but spend as much as you can afford on measuring devices.


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## Killer Brew (29/8/16)

Lyrebird_Cycles said:


> Using the right calculation will give you the right result.
> 
> If you use the Brewer's Friend calculator and put in a correction factor appropriate for attenuated wort (0.90) it gives an equivalent FG of 3.35 oP (1013).
> 
> I explained in #15 above why the correction factor changes with attenuation.


Ok, will check that out. Have been using a PDF which cross references starting Plato gravity with current (so no correction factor). Had assumed all of the calculators worked the same. Wrongly obviously.

Is there then somewhere a list of wort correction factors based on the stage of fermentation or is this the required math you speak of?

Actually, don't worry. Found it. Will read through this one tonight and see if I can work it out.
http://www.brewersfriend.com/how-to-determine-your-refractometers-wort-correction-factor/


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## Elz (29/8/16)

Does anyone use the refractometer tool available in Beer Smith 2. It seems to work well for me, in that I am mostly hitting numbers expected. I did have to calibrate the software when first setting it up with a hydrometer measure. If anything my FG seem to be too low; that is expecting 1.010 and Beer Smith calculating 1.006-7


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## Lyrebird_Cycles (29/8/16)

Killer Brew said:


> Is there then somewhere a list of wort correction factors based on the stage of fermentation or is this the required math you speak of?
> 
> Actually, don't worry. Found it. Will read through this one tonight and see if I can work it out.
> http://www.brewersfriend.com/how-to-determine-your-refractometers-wort-correction-factor/


No that doesn't have the correction factors for worts at different attenuations, as far as I know no-one has published them. I use ones I worked out myself.

I've seen a reference to something in Kunze, I am chasing down a copy so I can cross check it. Once I've done that I will write something up.



Elz said:


> Does anyone use the refractometer tool available in Beer Smith 2. It seems to work well for me, in that I am mostly hitting numbers expected. I did have to calibrate the software when first setting it up with a hydrometer measure. If anything my FG seem to be too low; that is expecting 1.010 and Beer Smith calculating 1.006-7


Is there any tool in Beersmith that works properly? If so I haven't found it. I use Beersmith and quite like the program, but the calculators are all useless IME.


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## Mardoo (29/8/16)

Lyrebird_Cycles said:


> No that doesn't have the correction factors for worts at different attenuations, as far as I know no-one has published them. I use ones I worked out myself.


Care to publish them?  I'd pay for that.


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## Killer Brew (29/8/16)

Lyrebird_Cycles said:


> No that doesn't have the correction factors for worts at different attenuations, as far as I know no-one has published them. I use ones I worked out myself.
> 
> I've seen a reference to something in Kunze, I am chasing down a copy so I can cross check it. Once I've done that I will write something up.
> 
> ...


That would be great. Thanks.


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## MHB (29/8/16)

Lyrebird_Cycles said:


> Don't laugh, I came very close to scoring a Hewlett Packard GC-MS package on Ebay a few years ago for under $7k. Probably a good thing I missed out, would very likely have been a source of domestic disharmony.


Not just the cost ($7k), had one of these at TAFF when doing Chem Dip, the lecturers scheduled all the HPLC/GC pracks into a very narrow window.
Apparently it took a couple of days to stabilise the vacuum in the MS and it spent the whole time sniffing ultra high purity Helium, worked out something like $100/day just to turn it on.
But OH what a toy, do some stuff that would startle you, we were looking at second and third order DDT degradation products in breakfast cereal, comparing "Organic" with just the regular stuff.
Mark


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## Lyrebird_Cycles (29/8/16)

Mardoo said:


> Care to publish them?  I'd pay for that.


Once I've had a chance to check Kunze I will write something up and post it to a thread here.

I cobbled the information together from a bunch of disparate sources and did some analytical work to back it up, I'd prefer to check all available sources before going public.


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## Lyrebird_Cycles (29/8/16)

MHB said:


> Not just the cost ($7k), had one of these at TAFF when doing Chem Dip, the lecturers scheduled all the HPLC/GC pracks into a very narrow window.
> Apparently it took a couple of days to stabilise the vacuum in the MS and it spent the whole time sniffing ultra high purity Helium, worked out something like $100/day just to turn it on.
> But OH what a toy, do some stuff that would startle you, we were looking at second and third order DDT degradation products in breakfast cereal, comparing "Organic" with just the regular stuff.
> Mark


Yeah I set the GCs in the lab in Perth up (we had three: one for alcohol, one for diacetyl and a back up in case one of the first two failed*). We used a lot of expensive gas.

* That sounds stupid except for the time we walked in one morning and the main control board in the alcohol GC had literally gone into meltdown: there was a pool of solder and components below it. We were back up and running in about an hour. Since bottling downtime was $20k per hour and these are primary checks, that was worth the price of the spare GC.


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## MHB (29/8/16)

It's been a while but
I think the slow bit was waiting for the high vacuum diffusion pump to settle down, if you had multiple units on a manifold it would make booting up pretty quick.
Mind you TAFE didn't have the newest models of anything - I remember one machine that was Pre-Doss, instructions had to be loaded in its own very unique language, the ICP literally fell off the back of a truck, got refurbished and sold to TAFE cheap.

Some of the newer generation of analytical equipment is spectacular, just wish it wasn't so stupid expensive (translate as I don't get to play with it!)
Mark


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## malt junkie (29/8/16)

I thought a Mass Spec could analyze the lot in one go; ie: alcohol, IBU, Bacteria or at least run them consecutively.


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## Lyrebird_Cycles (29/8/16)

MHB said:


> Mind you TAFE didn't have the newest models of anything - I remember one machine that was Pre-Doss, instructions had to be loaded in its own very unique language, the ICP literally fell off the back of a truck, got refurbished and sold to TAFE cheap.
> 
> Some of the newer generation of analytical equipment is spectacular, just wish it wasn't so stupid expensive (translate as I don't get to play with it!)
> Mark


Tell me about it: in the same lab as the 3 GCs we had an Anton Paar densitometer so old it had a Nixie tube display.







Image is a counter timer with Nixies, couldn't find an image of the AP.


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## Lyrebird_Cycles (29/8/16)

malt junkie said:


> I thought a Mass Spec could analyze the lot in one go; ie: alcohol, IBU, Bacteria or at least run them consecutively.


Per the above, I didn't buy the GC MS, the GCs in the lab mentioned used flame ionisation detectors IIRC.


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## Lyrebird_Cycles (30/8/16)

Rather than continuing to kidnap this thread with my ravings, I have started a new thread:

http://aussiehomebrewer.com/topic/92065-towards-an-understanding-of-refractometers-in-wort-and-beer/#entry1398654

enjoy.


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