Hydrometer Calibration Q's

I've come to the conclusion that my hydrometer is off by a couple of points, so want to figure out how to be more accurate with what I have (i.e. I'm not going to shell out for a $75 pro set)

1. Everything I've come across for calibrating your hydrometer suggests to calibrate it using distilled water at the appropriate temperature. This doesn't seem right to me. I don't brew with distilled water. I brew with my tap water and want to know how much sugar is in it, right? So it seems I should use my tap water as the zeroing standard.

2. If my hydrometer is floating high, say by 2 points. Is it valid to simply weight it slightly (i.e. by adding a couple of pieces of tape, a piece of clay, whatever) to zero it in my calibration fluid?

Thoughts??

Unless you have some unusual tap water, your hydrometer won't be able to detect the difference. Use either tap or distilled water to check it. Don't bother adding weights and such to the hydrometer to adjust it. It's much easier to simply add or subtract the error from the reading. Hight quality hydrometers are relatively inexpensive. I have three or four hydrometers and IIRC, the most expensive one was only about $15 and they all seem to be reasonably well calibrated and zero out with plain water distilled or tap. Paying $75 for a hydrometer would be really stupid IMHO.

The hydrometer should be calibrated to distilled water, so you can see if it's reading correctly. But my tap water is very close, when I tested it. My tap water might be 1.0001.

Anyway, check it in 60 degree water. If it's reading high or low, just adjust your reading when you use it for beer. I had one that was .002 off. I just added .002 to each reading, and that worked fine.

YooperBrew said:

The hydrometer should be calibrated to distilled water, so you can see if it's reading correctly. But my tap water is very close, when I tested it. My tap water might be 1.0001.

Anyway, check it in 60 degree water. If it's reading high or low, just adjust your reading when you use it for beer. I had one that was .002 off. I just added .002 to each reading, and that worked fine.

Click to expand...

Are you really concerned about a difference of 1/10,000th? That's wild!

Catt22 said:

Are you really concerned about a difference of 1/10,000th? That's wild!

Click to expand...

No, not at all. I'm just saying that my hydrometer in tap water reads very close to what it does in distilled water.

Probably more variation in the way each person reads the hydro then in the difference between tap & distilled.

Weighting it is a good idea as sometimes you forget to adjust the numbers. Of course it could be off in the other direction in which case hacking off a piece of it would not be so good. LOL

Yeah, if there's nothing wrong with the concept of weighting the hydrometer (since mine floats high), I'd rather do that than subtract 1.7 points (or whatever it is) every time I use the thing.

tap water it is....