Refractometer

[shaunous]

I'm not asking how to get wort into a cube PF, and if that's not what you thought, well I'm fuked as to what your post means.

Or maybe we're both drunk.



P.s. I'm boiling part of the wort, yes. But you cannot take a sample of that as it becomes thinned out by water when u top up in the fermenter.

 

[pk.sax]

Ah right... So you are boiling the extract with water and then diluting it out. Surprised if isn't mixing then, esp in a cube n shake....

Or are you adding still more extract cold into the cube? Suggest you add any extract dissolved in hot water to make sure it dissolves quickly when you mix it into the cold water. I dunno, that's all I can think of. No, not telling you how to get wort into cube, just about first adding extract to hot water in whatever way before you add it to the colder water to make up volume.

 

[CrookedFingers]

Could you whack a tap on the cube ?
then you could just pour it.

Ooops, just re-read your longer post Shaunous, you do have a tap on it.

 

[TheWiggman]

How do yáll take a sample from the fermenter before you throw the yeast in to get your OG?

For kit stuff - not that I do it any more - I didn't take an OG. I just read what's on the tin and know it'll be around 4.5% or whatever.

Personally, I take a reading using a refractometer after the boil for completeness's sake. Everything is well mixed up by then. It tends to be slightly lower than the hydrometer reading and I blame this on the temperature, even though I try to let it cool.

Once IN the fermeter, I add the yeast. Seal, then wait 12-24h until lag phase has mostly set in, and take a sample from the tap into the hydrometer tube. From then onwards I keep the sample in the tube and monitor it, and the refractometer stays in the cupboard.

 

[shaunous]

Yeh Fuks me PF, I'll check the gravity this morning once all the hop material has had time to settle, even though it's bout 12hrs after I threw the yeast in it shouldn't have changed much.

Didn't matter what I did, drawing a bit off the top inch gave me an OG way to low, then drawing from the tap in the bottom of the cube (with clearly small amounts of hop material visible) gave me one to damn high. I couldn't get a happy medium. Not that I tried and tried, I got the shits and threw the yeast in.

 

[shaunous]

For kit stuff - not that I do it any more - I didn't take an OG. I just read what's on the tin and know it'll be around 4.5% or whatever.

Personally, I take a reading using a refractometer after the boil for completeness's sake. Everything is well mixed up by then. It tends to be slightly lower than the hydrometer reading and I blame this on the temperature, even though I try to let it cool.

Once IN the fermeter, I add the yeast. Seal, then wait 12-24h until lag phase has mostly set in, and take a sample from the tap into the hydrometer tube. From then onwards I keep the sample in the tube and monitor it, and the refractometer stays in the cupboard.

So you do a mini ferment in the hydro tube?

Once IN the fermeter, I add the yeast. Seal, then wait 12-24h until lag phase has mostly set in, and take a sample from the tap into the hydrometer tube.

I'll check the gravity this morning once all the hop material has had time to settle, even though it's bout 12hrs after I threw the yeast in it shouldn't have changed much.

 

[TheWiggman]

Mini-fermet yes. I keep it near the fermeter so the conditions are the same (excluding wild yeasts) so it's a good approximation of where it's up to. The tightarse in me says 'DON'T TAKE ANY MORE UNNECESSARY SAMPLES AS THAT COULD BE BEER ONE DAY'. Or lawn food, depending on God's mood.
Oh and for reference, I've never seen a difference in gravity in the first 24h except for a 3068. There's a party going on in every fermenter when this yeast's used.

I can't for the life of me work out the difference in densities between the top and the bottom of a cube you're facing. Maybe God's at play here as well? If there is a separation in fluids then the heavy stuff will settle to the bottom, but if you mixed it well this really shouldn't happen. But evidently... it has.

 

[shaunous]

Well after checking the 2 brews I had going, one only got yeast last night, the other had been fermenting for a week, I have correct and realistic Gravity readings.

So morale to my story, take OG readings when doing Partials/Extracts after a day or less in the fermenter.

 

[Dazzbrew]

Just got my first Refractometer :kooi:

I noticed on THIS website it states;

"When looking through the monocular, be sure you are using natural light to view the readings; you should not read a refractometer in the prescence of fluorescent light."

Does this really matter?

I'd like to use it after dark if possible and my shed lights are fluerescent.

I would like an answer on this too.
I do my brewing at night, on my back verandah and the only light is my censor light which has 2 globes which I think may be Halogen.
Would this light give a different reading to natural uv light? possibly due to differences In wave length?

 

[Mr B]

I brewed and checked yesterday, no difference between sunlight and fluorescent light. Sunlight was a bit brighter though.

 

[DJ_L3ThAL]

Yep I've brewed day and night and haven't found anything funny with reading by lights

 

[Dazzbrew]

Good to know thanks

 

[Ditchnbeer]

I've really got to thank Brewer Pete here.
I have been really unhappy with using my refractometer lately, and today, while watching the Superbowl, I thought I would learn something by reading thru (almost) all the pages about refractometer on the AHB. And I struck gold by Brewer Pete's posts on using & calibrating. I followed his advice and before I knew it my refractometer was reading a SG I was targeting! So here is what I learnt:
- Keep the glass pristine clean; wash with water then wipe clean with good quality cloth before use. Maybe mine had been streaky??
- Calibrate to zero with fresh water at ~20 degrees
- Mix 60gms of sugar with 470mls of water and shake until sugar disolved.
- Refractometer shoud read 1043 (11.04 Brix) or within range of 1041 - 1046 ( 10.6 - 11.8 Brix).
I owe you a beer Brewer Pete!

 

[fraser_john]

I would like an answer on this too.
I do my brewing at night, on my back verandah and the only light is my censor light which has 2 globes which I think may be Halogen.
Would this light give a different reading to natural uv light? possibly due to differences In wave length?

They recommend natural sunlight because the light rays from the sun are parallel to each other, non-natural light such as flouros etc have light rays that don't run parallel and can result in a not quite as clear line. Try a reading on a cloudy day and you will note that the line is not a perfect split between blue and white, but it will be a fuzzy have a guess where it is kind of union between the two.

 

[TheWiggman]

Sure about that Fraser_john? Natural light should be random. If it was polarised like you say then when wearing polarised sunnies, tiling your head 90° would block out all light.

 

[DJ_L3ThAL]

It's because it gets refracted through clouds isn't it ? Also you'd be getting other light bouncing off other objects, not pure sunlight no matter how clear the sky was.

 

[DJ_L3ThAL]

You may have a non-temperature compensating refractometer so you have to adjust the results on every reading.

Or are you doing readings during fermentation with alcohol in the sample drops? That will skew the results as well and needs corrections applied.

I primarily got mine for #1 Mead, #2 Cider. I have not applied it *yet* to brewing beer.

I actually now have to get a really damn good/accurate hydrometer so I can cross-compare calibration issues and results.


Hydrometer:
+ : Dunk it in an take a reading
+ : Good for final readings with alcohol
- : Needs temperature corrections
- : Large sample size not good for small batch brewing (which is done outside of the realm of beer)
- : Very fragile, costs add up when you keep buying decent hydrometers over and over again

Refractometer:
+ : Only two liquid drops sample size
+ : Good for original readings in a portable environment (in the vineyard, next to a fruiting tree, etc.)
+ : Rather rugged, especially compared to a hydrometer, but of course within limits
- : Needs temperature corrections if you didn't buy an automatic correcting one
- : Needs corrections if you have alcohol in the sample
but all corrections taken care for you by This Website: Homebrew Recractometer Calculations


Use both is my philosophy. Both in the areas where their particular strong suits shine through.

Anyone got a new link to the above correction calculators?

 

[TheWiggman]

This site - https://www.polarization.com/sky/sky.html - states pretty clearly that sunlight is polarised, and actually notes what I said (that when you tilt your head light is blocked out). The rays however switch from vertical to horizontal depending on the position of the sun.

 

[fraser_john]

Sure about that Fraser_john? Natural light should be random. If it was polarised like you say then when wearing polarised sunnies, tiling your head 90° would block out all light.

I never said it was polarised, that is different to being parallel in direction of travel. Probably would have helped to have more info

Polarisation cuts out the "axis" of a wave so assume two sine waves coming towards you all you really would "see" is a + one wave horizontal, one wave vertical, polarisation blocks one axis, so you would only see - or | depending on which one the polarisation blocked. But, when the two waves are travelling towards you , they are perfectly parallel to each other.

 

[TheWiggman]

That does make them polarised though. If all light runs parallel it is polarised, regardless of whether it was filtered with a polarisation filter. By definition, "Polarised light waves are light waves in which the vibrations occur in a single plane" - exactly as you're (correctly) suggesting.

Ed: thought I'd add this word: semantics
What you've raised explains why refractometers perform better in natural light.