Hydrometer

**kontreren** · 08-29-2008, 06:41 PM

I have read books on whiskey making, beer making, and searched the internet. They all talk about SG, BG, FG, etc. and I half way understand the gravity concept. However, I feel like a complete moron because I can not understand how to read the thing. I filled up the little plastic testtube looking thing (forget what its called) to 100 with spring water. Then I put in the hydrometer. After spilling some overflow onto the counter the water level was at the top of the plastic testube thingy and the hydrometer was floating where the water level was at 1.000 (all the way at the top). So after all this verboseness...how do I actually read this thing. KISS English only please.

Beerthoven · 08-29-2008, 06:44 PM

Is this helpful, or do you need to know how to interpret the units that you are reading?

**Revvy** · 08-29-2008, 06:46 PM

1)Take temp of sample
2)Place hydrometer in sample, tap it or give it a spin to knock it off the side of test jar
3)Let it rest for a couple minutes

Adjust the reading for temp (depending on what your hydrometer is set for 60 or 60 degrees)

THis is a good temp adjustment calculator.

http://hbd.org/cgi-bin/recipator/recipator/hydrometer.html

**kontreren** · 08-29-2008, 07:07 PM

Quote:

Originally Posted by Beerthoven

Is this helpful, or do you need to know how to interpret the units that you are reading?

I have no clue what you are talking about. Please tell me how to find the specific gravity of water. I think that will go a long way towards educating me. I have a tube that has a max number of 100 on it but when I fill it with water and put the hydrometer in it overflows. So what is that tube and those numbers for? And at the water level (which is at the top way above the 100 now) the hydrometer floats at 0% and 1.000. There is also another scale because this is a triple scale hydrometer. Help me understand what I'm looking at, reading isn't helping.

planenut · 08-29-2008, 07:09 PM

I think you are reading the graduations on the tube and not the graduations on the hydrometer...
The tube does not need any numbers, it's purpose is just to hold the brew or water in this case.

**kontreren** · 08-29-2008, 07:10 PM

Quote:

Originally Posted by Revvy

1)Take temp of sample
2)Place hydrometer in sample, tap it or give it a spin to knock it off the side of test jar
3)Let it rest for a couple minutes

Adjust the reading for temp (depending on what your hydrometer is set for 60 or 60 degrees)

THis is a good temp adjustment calculator.

The Beer Recipator - Hydrometer Correction

So do the numbers on the tube mean anything? Am I just suppose to fill the tube so it doesn't over flow and ignore the markings on it? And please remind me what should the specific gravity of plain ol' spring water be and what do I do to test it and make sure I know what I'm looking at. I'm completely lost. No matter how many books I've read, this somehow continues to elude me. Help!

**ShortSnoutBrewing** · 08-29-2008, 07:13 PM

I think you're trying to hard. It really is quite simple. You want enough liquid in your tube to allow for the hydrometer to float. Ignore your 100 on the tube (I'm guessing it's a 100ml tube).

You've already found the SG or water. You've said twice it's at 1.000. That's it. If you replace the water with fresh wort or even a finished beer you will get a different reading. I think Bobby_M has a video on how to read a hydrometer. That may be very helpful for you...

YouTube - Hydrometer - Brewing Beginner Series

flyangler18 · 08-29-2008, 07:13 PM

And by the way, if your hydrometer is reading 1.000 for water, it's doing exactly what it should. Water should read 1.000.

Beerthoven · 08-29-2008, 07:14 PM

The numbers you want to pay attention to are the ones on the hydrometer itself, not the sample tube. The numbers on the sample tube are probably just there to show you how much you have in there. My sample tube doesn't have any numbers on it.

The specific gravity of pure water is 1.000, generally speaking. Dissolve 1 or 2 teaspoons of sugar in your water, and put the hydrometer back in. It should read higher than 1.000, say 1.030 or something like that. This means that the sugar you added has raised the density of the solution to be 3% greater than pure water.

**Revvy** · 08-29-2008, 07:14 PM

You only need to fill your sample jar about 3/4's of the way so that when you put your hydrometer in the jar, it floats, and the beer doesn't over flow (though if it does, that's ok)

Don't concern yourself with water, if it's a new hydro, it is calibrated for distilled water already, or any of the scales on the hydrometer EXCEPT the scale in my picture, the one with .099 at the top.

If you look at that one, the Specific gravity is approx 1.072. We pronounce that "Ten seventy two"