What do these numbers tell me, please?

[bobtheUKbrewer2]

I use wort correction factor 1.04
actual OG 1.044
actual brix 11.6
corrected OG (brewers friend) 1.045
actual final gravity 1.019
actual final brix 7.2

OG corrected (brewers friend) 11.15, 1.045
FG corrected (brewers friend) 3.98 P 1.016


ABV (brewers friend) 3.89

 

[Pappers_]

What the numbers tell me is that you brewed a sessionable beer with low attenuation, meaning it may be a little sweet. How did it turn out?

 

[jekeane]

What was your timetable? What were you expecting? If you were shooting for a session sweet beer then that's what you got. If not it tells you that your fermentation was not complete or stalled. Or you had a lot of unfermentable sugars. Or you under pitched your yeast. The numbers alone could say many things. We don't know what you were expecting from those numbers or what you did to get them.

 

[JohnSand]

It think may mean that your beer isn't finished fermenting.
Your original gravity tells you how much stuff was added to the water in your wort. Your final gravity tells you how much of it fermented and became alcohol. The gravity of water is 0, it doesn't change. The numbers after the decimal are important. Your attenuation (how much sugar the yeast converted to alcohol) was about 64%. Usually it would be 70-75%. What was your recipe and yeast? Some yeasts don't attenuate well, and some sugars don't convert.

 

[Smellyglove]

Is the wort correction factor something you measured against your (preferrably correct) hydrometer?
If not, then you need to calibrate your refractometer against your hydrometer.

And using a refractometer post-fermentation isn't always accurate, it can be a couple of points off, after converting the numbers.

The best way is to always use a hydrometer to get a reading of the FG, but you can use the refractometer to check when you've reached FG.

 

[bobtheUKbrewer2]

I only bottled it yesterday. I mashed at 69 deg C and was aiming at a well hopped 3.8 % bitter.

Since I provided actual OG and FG I was hoping for comments on the refractometer readings.

Beer was clear and no visible gas bubbles - I always bottle my beers at this stage.

Yeast - safale 04

 

[swerner]

And using a refractometer post-fermentation isn't always accurate, it can be a couple of points off, after converting the numbers.

The best way is to always use a hydrometer to get a reading of the FG, but you can use the refractometer to check when you've reached FG.

I agree with smellyglove, I never use a refractometer to measure FG, Use a hydrometer.

 

[bobtheUKbrewer2]

...yet there are very complicated formulas that convert final refractometer reading into FG - they seem to take account of the alcohol in solution.


I still do not understand what final SG with a hydrometer means, as we have water with some "maltose" and some "ethanol" in it. If we start with just maltose solution with a SG of 1.050, and we dilute it down with water until it is SG 1.010, and take a litre of it.....................then calculate how much pure ethanol to add to a litre to make it 4% ABV..............and add that pure ethanol to the litre of 1.010 maltose, the 1.010 will clearly drop .......but how much ?

In the real world I make a brew with OG (hydrom) 1.044 and after 7 days I measure the FG (hydrom) as 1.012..........I don't know how much alcohol is present so I have to guess the adjustment.

Is there a boffin on here to give us a best estimate for 4% and 5% (ish) beers ?

 

[billl]

"Since I provided actual OG and FG I was hoping for comments on the refractometer readings.
"

The refractometer reading for OG is within the margin of error of the testing equipment. It's a fine way to measure the starting gravity of the wort.

The refractometer reading for your FG is questionable due to the "correction" formulas. It is introducing an additional source of error into your measurements. Always go with a hydrometer post fermentation.

Yes, the alcohol in the beer does lower the hydrometer reading, but the impact of that is pretty minor on a beer scale. The alcohol is only a very small proportion of the total solution and the gravity of water and alcohol are relatively close.

 

[bobtheUKbrewer2]

how small is pretty small - 002 ?

 

[bobtheUKbrewer2]

1 litre of 4% ethanol has SG of 0.991
1 litre of my "maltose" has SG of 1.010

mix the 2

SG= 1.0005 so the hydrometer SG should have 0.009 knocked off it ?