Refractometer usage

[droid]

@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.

 

[RdeVjun]

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.

 

[Lyrebird_Cycles]

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 **** sticks to it.

 

[Bribie G]

@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.

 

[Mardoo]

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

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

 

[Matplat]

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

 

[Ducatiboy stu]

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

 

[TheWiggman]

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 ***** me)

 

[Lyrebird_Cycles]

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

 

[Matplat]

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...

 

[Tex N Oz]

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/

 

[Lyrebird_Cycles]

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.

 

[MHB]

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

 

[Ducatiboy stu]

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

You might get away with a rice gull

 

[mikec]

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.

 

[mikec]

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?

 

[Killer Brew]

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

 

[evoo4u]

How does natural daylight fit in with that?

 

[Killer Brew]

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

 

[Droopy Brew]

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.