Refractometer Reading

[lukasfab]

i have read some of the sticky in the other section but dont have the answer

can you successfully read fermented wort instead of the hydro?

i have brewmate and there are 3 conversion calcs but not sure how/which to use


cheers

 

[seamad]

Think in bs2 you enter OG in brix and then the hydro reading in brix. Not sure if that helps you.

 

[manticle]

I'm not sure how good this one is as I've only just started using a refractometer but the comparison I made with my hydrometer and refrac yesterday seemed on par

http://www.brewheads.com/refract-currentgrav.php

 

[kelbygreen]

I use this one and it always seems to be right. Well except for the last time I was working it of my preboil gravity and not my OG :huh: wondered why the hydrometer was 1016 and the refractometer calculator 1023 lol Then I worked out the OG from the FG and refractometer and it was 1052 which is what it said on the beersmith sheet lol Helps if you look at the right section.

Edit: forgot the link http://onebeer.net/refractometer.shtml

 

[lukasfab]

what do you put in the current and origanl reading? sorry for the noob question

could you give me an example?

cheers

 

[Wolfy]

can you successfully read fermented wort instead of the hydro?

It depends what you call 'successfully'.
As you've realized you can't directly read the gravity of fermenting/fermented wort using the refractometer - you need to use a calculation to extrapolate or estimate the gravity.
Once that is done you should have a good, consistent but estimated calculation of the gravity, and for most (home brewers especially) that is 'successful' enough - even if it might not be absolutely exact.

 

[QldKev]

what do you put in the current and origanl reading? sorry for the noob question

could you give me an example?

cheers

Alcohol will scew the result of the reading via a refractometer.

So once fermenting has started you need to offset the reading by taking into the account of the gravity/refact reading of before you started fermenting, aka the OG to work out the current alcohol level to perform the adjustment.

So
Original Gravity, basically the gravity when you pitch the yeast
Current Gravity, the reading at that point of time.

The calculators linked to can then apply the correction to the brix reading to get a correted gravity reading.

 

[Dazza88]

I know that my "corrected" refract readings are always a little lower than the hydrometer - up to 5 points. So now i use a refract to check the fg has stabilized.


I use onebeer.net calculator, on phone cant link.

 

[lukasfab]

got it guys, many thanks :lol:

will get some distilled water and calibrate the refrac. as i only had filtered water yesterday

both links posted come up nearly the same and so does the calc in brewmate, close enough anyway

 

[MaltyHops]

There's also this.