Refractometers From E-bay (hong Kong) Any Good?

[Phoney]

There are calculations & adjustments? I just use Docs Brix to SG sheet..

 

[[email protected]]

It showed that, or that the result when you had applied the appropriate calculations and adjustments?

What calculations? I thought you just read the SG from where the blue line is. Mine said it compensated for temp between 10 and 30C

 

[bignath]

Just brewed my first brew with the refractometer. I did a stout and maybe you can guess my question................
Is it normal for black beers to make the line in the refrac to be fuzzy/not clear? Its nice and sharp with water and beer I got in the fridge but I am assuming that the black beer/stout must have some effect on the .....refraction?

Steve

One thing i've found is to make sure you don't have any air bubbles on the prism surface when you close the lid. Or hop matter either. Both of those scenarios can create a really blurry line.

I've often also found that natural light is best for getting a clear reading, but if you're brewing at night, the closer you can get to a lightsource the clearer mine is too. Also changing the angle of the refractometer to the lightsource can help awell. Trying lifting or dropping your head as you look through it. Works for me.

Nath

 

[Superoo]

"There are calculations & adjustments? I just use Docs Brix to SG sheet"

Yes, there are adjustments for the alcohol during / after fermentation.

This may or may not be your problem... hope it is, then your refract is ok...

Edit : SORRY - dont have a quick link, but of you read this post from the start there are, and there are more explanations...

 

[SJW]

Nath, you are correct, now that its in the fermenter and the crap has settled it is a lot sharper line, still not a sharp as the pilsner or other pale beers I have on tap or water but its a lot better. I guess with 10% Roast Barley this coul be afecting the relection/refraction. The temp of wort never appeared to make a diff, it still read true with the hydro.
One thing that did make the line sharper was if I squeezed the plate down on the prism squashing the wort sample, making the wort sample thinner.
Still a great bit of kit.
Looking forward to brewing a pale beer next

 

[Wolfy]

There are calculations & adjustments? I just use Docs Brix to SG sheet..

What calculations? I thought you just read the SG from where the blue line is. Mine said it compensated for temp between 10 and 30C

If I didn't know better I'd guess both of you guys were taking the piss, but assuming you are serious ...

A refractometer is really only accurate for unfermented wort, once there is alcohol in the sample the alcohol changes the refractive index and 'distorts' the reading, so the number the refractometer gives you is not directly the actual gravity.

Anytime you use a refractometer AFTER fermentation has started, you MUST to apply a calculation (or use a chart) to convert from what the refractometer reads (sugar + alcohol) to the 'correct' gravity (sugar).
The relationship (and hence the equation or chart) depends on the Original Gravity, so you enter the OG AND the current reading from your refractometer and the formula will calculate the correct current gravity estimate for you - without applying the calculation and knowing your OG the 'gravity reading' will most likely be different to what the 'actual gravity' is.

Most brewing software (like Beersmith) have a refractometer Tool/Calculator that you can use to perform the calculations for you, else there is a spreadsheet that is floating around too, or you can find the exact formula and do it the hard way each time.

 

[[email protected]]

If I didn't know better I'd guess both of you guys were taking the piss, but assuming you are serious ...

A refractometer is really only accurate for unfermented wort, once there is alcohol in the sample the alcohol changes the refractive index and 'distorts' the reading, so the number the refractometer gives you is not directly the actual gravity.

Anytime you use a refractometer AFTER fermentation has started, you MUST to apply a calculation (or use a chart) to convert from what the refractometer reads (sugar + alcohol) to the 'correct' gravity (sugar).
The relationship (and hence the equation or chart) depends on the Original Gravity, so you enter the OG AND the current reading from your refractometer and the formula will calculate the correct current gravity estimate for you - without applying the calculation and knowing your OG the 'gravity reading' will most likely be different to what the 'actual gravity' is.

Most brewing software (like Beersmith) have a refractometer Tool/Calculator that you can use to perform the calculations for you, else there is a spreadsheet that is floating around too, or you can find the exact formula and do it the hard way each time.

Thanks Wolfy, guess I should have looked at the instructions.

 

[Phoney]

+2

Thanks Wolfy! All this time I didnt even realize beersmith had this feature.

 

[Rieewoldt]

Recieved my refractometer recently, and brewed yesterday. Results seemed consistent with the hydrometer
But still sceptical! Will be using both till it earns my trust.

 

[SJW]

Kayne, what type of beer did u brew, and was the line sharp? I suspect with dry stout, like I did, all the roast barley must be causing the line not to be a sharp as the water sample test, or pale solutions that appear to work fine.
As for it earning my trust.....yes, it did appear to be very accurate, maybe too accurate. With mine compared to the hydro sample the refrac was reading slighjly lower by a point or a point 1/2, but as the line was fuzzy I took it from the upper fuzzy of the line and it was pretty close.
Why I say these thing could be too accurate, I understand there is no such thing, but I had a 2 litre jug of Iodophor in water and I dipped my s/s mixing spoon in the boil once and then back into the jug. I took a sample out of that and the refrac showed a result of one point, and thats just from a few drops off the spoon in 2 litres of water.
A few more brews and it should of earned my trust too.

Steve

 

[stux]

that sounds like brewing porn to me....Got a linky??

Try http://cgi.ebay.com/Brix-Refractometer-0-3...=item35b157b389

 

[felten]

I keep hearing very bad things about refractometers with the inbuilt LED's. Anyone have one and having problems with it?

 

[mickpc]

See my previous post in this tread for an excell spreadsheet that will take into acount of the alchol content.


Beers Mick

 

[Rieewoldt]

Kayne, what type of beer did u brew, and was the line sharp? I suspect with dry stout, like I did, all the roast barley must be causing the line not to be a sharp as the water sample test, or pale solutions that appear to work fine.
As for it earning my trust.....yes, it did appear to be very accurate, maybe too accurate. With mine compared to the hydro sample the refrac was reading slighjly lower by a point or a point 1/2, but as the line was fuzzy I took it from the upper fuzzy of the line and it was pretty close.
Why I say these thing could be too accurate, I understand there is no such thing, but I had a 2 litre jug of Iodophor in water and I dipped my s/s mixing spoon in the boil once and then back into the jug. I took a sample out of that and the refrac showed a result of one point, and thats just from a few drops off the spoon in 2 litres of water.
A few more brews and it should of earned my trust too.

Steve

Hi steve,
twas a pale with centennial and citra. yeah would be even more sceptical on anything heavier ie stout. Still. it is a beaut beer toy.

edit: I found using natural light decreased "fuzziness"