2nd opinion on hydrometer reading
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flars
Well-Known Member
It does look like 1.008. Things to watch for; CO2 in the sample can float the hydrometer higher. Sample temperature can skew the reading when the sample temperature is not the same as the calibration temp of the hydrometer.
Since it seems stuck to one side it's hard to tell but 1.010 looks closer. Try spinning it and read at the meniscus.
Also adjust for temp.
Also adjust for temp.
raouliii
Well-Known Member
If you find yourself questioning your hydrometer reading's accuracy, I suggest testing it against distilled water, (1.000) at calibration temperature. The calibration temperature should be on the hydrometer label.
DurtyChemist
Well-Known Member
I'd need a photo looking at where the miniscus meets the hydrometer. I agree that it looks like its stuck to the tube.
Right. Bend over and read it at eye level, and look at where the meniscus crosses the hydrometer. Looking down at it, it's impossible to read. Spin it, so it doesn't have bubbles under it, and so that it doesn't touch the side. Then bend down, and see where it reads.
Since everyone just keeps saying look at the meniscus, and your picture is not from eye level, I think reading this might help a bit with how to read your hydrometer. Just the "measuring volume" section goes over how to read graduations. The same rules for reading graduated cylinders apply to hydrometers. It has a couple pictures to help, too.
http://www.chem.latech.edu/~deddy/chem122m/L01U00Measurements122.htm
http://www.chem.latech.edu/~deddy/chem122m/L01U00Measurements122.htm
The meniscus, is the curve on the surface of the liquid. Just saying read from the meniscus doesn't provide enough information. The reading should be made level with the bottom of the meniscus (or the lowest level of the liquid surface).
Looks like the top of the meniscus is at 1.008 in the picture, and the bottom is about 1.010. The correct reading would be at the bottom (or 1.010 as best as I can tell).
You also need to correct for liquid temperature. If that is at room temperature, you probably need to add .001 to the reading.
Looks like the top of the meniscus is at 1.008 in the picture, and the bottom is about 1.010. The correct reading would be at the bottom (or 1.010 as best as I can tell).
You also need to correct for liquid temperature. If that is at room temperature, you probably need to add .001 to the reading.
OP
OP
ThunderpantsBrewing
Well-Known Member
Thanks guys. It was stuck to the side, as it was very hard to keep it off in the tube I used. I went to take a hydrometer reading and discovered that somehow the bottom of my hydrometer flask had broken, so I improvised and used the tube my hydrometer came in. It has a much smaller diameter, so I had a bit of trouble. I'll just call it 1.010 for now, and I'll check it again in a few days with a real flask. This beer had a 1.080 OG, so I'm happy either way.
flars
Well-Known Member
I use the shipping tube for samples also. I hold the tube in my hand to read the hydrometer scale. Spinning the hydrometer helps orient the tube vertical to keep the hydrometer off the side of the tube.
wardens355
Well-Known Member
Place the hydrometer on a level surface so it floats in the middle of the cylinder and read from eye level. If you still have the instructions, it will tell you exactly how the hydrometer was calibrated to be read. Apparently some are top of meniscus, some bottom of meniscus. If you don't have directions I would assume bottom.
Deleted: Duplicates what's in #11.
raouliii
Well-Known Member
Calibrate with distilled water and determine where 1.000 is the accurate reading. Top/bottom/+/-.
The problem with that is that wort and water have different surface tensions and because of that the meniscus shape is different. The best hydrometers are calibrated with a fluid that has the same surface tension characteristics as wort/beer.
