Hydrometer reading help

[SippinSudz]

Hey all.
I'll start with the recipe:
1can of coopers Canadian blonde
1000g light gold DME
300g Dextrose
1 pack yeast that came with coopers
Fermented at 20°C 12 days so far.
Topped up to 21L

OG - 1.042
2 weeks later 1.006
Will wait 3 days and take another reading.

Someone told me my FG would be 1.012, but I'm much lower than that.
Will this dip lower if I give it a third week? I'm not sure how much ABV there will be with the added .5% when priming bottles is done.

I know in pics the hydrometer is touching the side, but when I read it from free float, and spinning off C02 it was 1.006

My first time using hydrometer in a brew, and I'm 6 brews in.


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[flars]

The SG is lower than what would be expected. It is possible an infection could be continuing the fermentation. It is also possible the hydrometer may not be calibrated correctly.
Was the specific gravity for the OG taken with the hydrometer or from the recipe? If the OG is from the recipe, does your hydrometer show the SG of distilled water as 1.000? The water should be at the calibration temperature, for your hydrometer. Calibration temperature is printed on the card inside the hydrometer.

 

[stpug]

Now test your hydrometer in 60F/15.5C water and determine where the 1.000 lines up in relation to the meniscus. As pictured, the gravity is somewhere between 1.007 and 1.010. It may be possible that your hydrometer needs to be read from the bottom of the meniscus which would put you closer to 1.010.

 

[SippinSudz]

Alright so here's my findings!

I measured tap water at a lovely 60°F almost on the nose.

I was shocked to see how high the meniscus rides up the hydrometer. I now know where and how to read the bloody thing, as well as I can see my hydrometer is out by .002

The bottom of the meniscus was reading 0.998 so it seems the hydrometer sinks a little further than it should in high quality tap water.

Now I'm wondering if this means the hydrometer is reading belowe meniscus, and with the adjustment around, should be about 1.010 or so.

I'll have to take another reading in a few days.

 

[unionrdr]

The pics show 1.008. The long lines with numbers are 10, 20, 30, 40,etc. The small lines in between read 2,4,6,8. You're at 1.008. The card inside the hydrometer will also say whether to read it at the top of or through the meniscus.

 

[SippinSudz]

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I have had this reading for about 48 hours now. A few days ago I believe it hit 1.013 and now I think I've finished off at 1.011

Ready to bottle?
It's a stout and not sure if I should wait one more week in the primary if that will even help at all.

 

[AlCophile]

Before a SG reading, I'd stir the ---- out of the sample to remove most CO2. Meantime, have you ever standardized the meter in pure water? Always do that, as sheet of paper in tube may move. Annnnndddddd....always take several readings, after spinning meter to dislodge bubbles.

 

[stpug]

I was shocked to see how high the meniscus rides up the hydrometer. I now know where and how to read the bloody thing, as well as I can see my hydrometer is out by .002

The bottom of the meniscus was reading 0.998 so it seems the hydrometer sinks a little further than it should in high quality tap water.

Now I'm wondering if this means the hydrometer is reading belowe meniscus, and with the adjustment around, should be about 1.010 or so.

I'll have to take another reading in a few days.

If you assume the final gravity is 2 points lower than the bottom of the meniscus then I would say your final gravity is 1.014 (Pictures show the top of meniscus at about 1.010 which would put the bottom at about 1.012, and adjusting 2 points lower on you hydro puts you at 1.014). IMO, 1.014 is a reasonable FG for a medium-gravity (1.05x) dry stout unless the OG was really high, in which case I'd want an even higher FG. Then again, maybe I've interpreted your post above incorrectly.

 

[SippinSudz]

That's absolutely true. I did not calculate the obvious -.02 points I started this thread originally for

OG was 1.043, which really should be 1.045, doh! with a FG of 1.014 it looks like. Now I must adjust the beer journal and remember this for next batch.