Final Gravity Only 0.02 below OG?

[chrisluki]

Hey guys

Before Xmas I posted about one of my brews that I was concerned was stuffed

http://aussiehomebrewer.com/topic/84206-i-think-i-have-a-problem-with-my-brew/

Anyway, I went ahead and bottled the brew tonight despite it still smelling a bit ripe...thought I may as well.

Didn't test the FG until after bottling (misplaced my refractomoter) and when I did it was 1.05 vs an OG of 1.052.

Not sure what has happened? Any thoughts?

Cheers

Chris

 

[Velu]

Make sure you take the reading with flat beer, and around 20 degrees.

Edit. And it's a 0.002 difference

Edit 2. Saw its a refractometer, ignore above advice

 

[mudd]

If the readings are right it sounds like it hasn't fermented at all to me. This will probably explode your bottles- dangerous if they're glass. Do you have a hydrometer, refractometers can give false readings.

 

[doon]

Have you corrected measurement as you are using a refrac

 

[dr K]

A refractometer measures the apparent percentage of sugar in a pure sugar solution using a known refractive index of a sugar solution, for our purposes and wine makers it is a fairly accurate tool. The percentage is expressed as Brix or Plato (a tiny difference but our purposes close enough).
Plato or Brix do not hav a lineal relationship to SG but for purposes multiply Plato x 4 and you have SG (12P = 1.048).
Alcohol will change the solutions RI dramatically (the more ethanol the geater the change).
You reort a FG of 1050, have you adjusted (as noted) ffor ethanol RI, my clalc show that your actual FG is lower, viz, 1048 or 12 Plato.

Take a 250ml glass of water, add about 30gm (6 x 5gm teaspoons) and dissolve, taste, you re tasting 12 palto or 1.048 solution.

K

 

[manticle]

Even if it's 1048, it's definitely not ready to bottle. Open them up and tip them out asap.
Start a new batch.

Measure gravity properly before bottling next time and buy some illegal fireworks if you need that kind of excitement.

 

[TheWiggman]

I agree with manticle, too many unknowns on a particularly important part of brewing that presents a very high - and genuine - risk of injury.
I personally use a hydrometer for fermentation as it eliminates any possibiilty of error (for FG anyway). I have faith in the refractometer, whereas I trust the hydrometer.

 

[maroubrabrewer]

Refractometers are only good for measuring pre fermented wort. You will need to use a tool such as this one http://www.northernbrewer.com/refractometer-calculator/ if you are using your refractometer for post fermented wort. I would suggest you use a hydrometer to get a gravity reading for post fermented wort. I am sure your FG will be a lot different.

 

[chrisluki]

Dumped it!

 

[TSMill]

Based on the pics in the original thread, some significant degree of fermentation has occurred, so either your OG or your FG measurement is out.

You can use your refractometer and hydrometer at the end of fermentation to back calculate your OG to check if that was accurate to start with, however my money would be on the FG measurement being out, I'd guess perhaps priming sugar has thrown your numbers out?

 

[The Giant]

Refractometers are only good for measuring pre fermented wort. You will need to use a tool such as this one http://www.northernbrewer.com/refractometer-calculator/ if you are using your refractometer for post fermented wort. I would suggest you use a hydrometer to get a gravity reading for post fermented wort. I am sure your FG will be a lot different.

That sir is the greatest link ever. Thank you

Oh how I wish I had this 2 weeks ago before I waited and waited and pitched another yeast and added nutrient all thinking it had stalled!!