hydrometer readings and calibration

[yonkersbrewer]

What is the correct way to take a hydrometer reading? I just bought a second hydrometer thinking that the first was mis-calibrated since it did not read 1.000 at 60 degrees with distilled water. Then I bought a second one (the $5 ones all the brewshops have) tested it - still the same deal. Then I left the water in the tube for a couple of hours to see what would happen. AHA! Now it seems to read correctly.

Does this mean that I have to let the wort sit around for hours to debubble? Tell me the BETTER way please!

[paul84043]

I have always thought that it's a relative measurement, meaning, that if your reading +.002 in water at room temp, then simply adjust your finishing reading the same amount.
What you're looking for is the rate of decrease and that the numbers are close (plus or minus .002 or so). I wouldn't sweat the calibration unless you're trying to get ISO 9002 certified or something like that.....

Whar REALLY matters is that you make good beer. :D

[YamahaXS]

Originally posted by paul84043
I have always thought that it's a relative measurement, meaning, that if your reading +.002 in water at room temp, then simply adjust your finishing reading the same amount.
What you're looking for is the rate of decrease and that the numbers are close (plus or minus .002 or so). I wouldn't sweat the calibration unless you're trying to get ISO 9002 certified or something like that.....

Whar REALLY matters is that you make good beer. :D

i completely agree.

Besides, hard water should be slightly more dense because of the minerals in it.

[paul84043]

True, you're quite correct, there are tons of other things that will contribute to your SG. "All other things" are never equal.

[BucksBrew]

I'm making my first batch of beer, Pilsner Urquell. I had an initial reading of 1.05 at 66 degrees.

This weekend I took a reading from my secondary fermenter using the flask hydro came in and it read 1.22 at 56 degrees.

I think the bubbles affected the reading plus it was a tight fit. It actually rubbed against the side a little.

Anyhow, this number seams odd to me. I will do another reading in 3 days in a larger vessel, if I can find something cheap and practical. If it is correct, I have a ways to go before it gets down to an est. 1.013. ANy feed back is appreciated. Thanks

[paul84043]

I tried to take a reading by putting my hydrometer into my "theif", it was as you described, an extremely tight fit and I did not get an accurate reading, I had to retake it using the hydrometer tube that I bought just for that purpose. (a bit wider)

Your initial of 1.05 is good, that's typically what I get as a corrected initial reading. At 70 Degres you would have to add .0018, my initial reading is usually 1.04 plus or minus a point. Corrected puts it right at your reading.

Your second reading, 1.22 at 56 degrees would correct to 1.217 (-.003 at 56 degrees)

Still a bit high. How long has it been fermenting? The colder fermentations can, and will take quite a bit longer.

Buy a purpose built hydrometer jar, it's worth the couple bucks to get decent readings, stress free.

Be patient, keep taking readings every two to three days, keep things as sanitary as posible and you can gently add your sample back into the fermentor.

It will level out and everything will be great!

Isn't this a blast? I think making your own beer is the coolest thing in thw whole world!! Then again, I have been accused of having no life of my own before......

[yonkersbrewer]

The funny thing is that I agree that the damn hydrometer is mostly useless in beer making! I usually wait a week between brewing and racking to secondary and don't worry about a reading. It takes a week because that is the amount of time between the weekends when I have the time to brew.

I got caught up in the tech talk that seems so important to so many here! The best thing I did was to start with a MR BEER without any of the fancy tools. It taught me that what we are doing here is cooking! And good cooks use intuition as much as a recipe or the thermometer.

[BucksBrew]

I'm making a lager and the fermentation takes a lot longer than Ale's. I don't want to bottle and have fireworks. So that is my concern with the readings and no burping from airlock. I'm still getting burps at 15-19 seconds apart.

It has been in secondary for 3 weeks coming up 3-12-03.

I'll have to take a trip to my local HomeBrew store or buy on online. Thanks.

[paul84043]

Hmmm, 3 weeks should be more than sufficient, your FG reading is a tad high still.

BUT....done is done, there's nothing you can do about it. (Nor does it mean that your beer is going to suck)

There are many things that contribute to higher than desired FG readings, the most commonly referred to are yeast type, proper pitching quantity of viable yeast, and oxygenation to give the yeast a kick in the butt.

I use the White labs liquid, I don't bother to do an activation batch a day before, but it's defnintely an otpion, they say you really can't pitch too much yeast (within reason). And I am going to try the pure oxygen injection to see what kind of a difference that makes.

I'd consult the beer gods and go from there. If your reading hasn't changed in the past 4 to 6 days, I would say that you're done.

[BucksBrew]

I'm thinking if the airlock is still burping I'll wait until I get a consistant reading before I bottle.

The temp has ranged from 48-58, no more than 4-5 degrees in a day. Outside temp affects where it is fermenting.

I don't think I aerated it enough when racked to primary fermenter. Live and learn I guess.

[danno]

as you have found out, the tube the hydrometer came in will NOT give you correct readings, you need to have a larger diameter container....

The easiest way to degas your sample is to pour it back and forth several times from a glass to your container, take your reading, then of course sample your sample... :D

[BucksBrew]

I thought there would be no bubbles, but there was. Thanks for the good info. You can read the recipes and books, but they don't tell you the minute details like I crave! Thanks again.

Joe

[paul84043]

Mine bubbles like mad when I try to get a sample out!! I will have to try pouring it back and forth a few times...thanks.

[mountain beer]

When I used the tube the hydrometer came in, i got wrong readings. When I bought the larger tube, i started to get better readings.

I have a site that I use that calculates my readings that I get from my hydrometer. Its pretty cool. http://leebrewery.com/beermath.htm
http://leebrewery.com/beermath.htm

[toneyc]

To get the bubbles off the hydrometer, all you have to do is spin it a couple of times.

I don't bother with the hydrometer for beer as I usually don't care how much alcohol is in it. The mead is a different story, though.

:) Toney.

[YamahaXS]

i take hydrometer readings just so I can estimate the alcohol content. otherwise, i have never worried about it.

that said, I did manage to explode some bottles once (a stout, first batch).

cheers and beers !

[paul84043]

Do you estimate potential alcohol content based on your Starting reading, or finishing reading? I treid that and noticed that as your SG drops back down, your Potential drops as well...

[YamahaXS]

Originally posted by paul84043
Do you estimate potential alcohol content based on your Starting reading, or finishing reading? I treid that and noticed that as your SG drops back down, your Potential drops as well...

you take starting and finishing readings. then assume that the drop in density is because your beer has less sugar and more alcohol in it.

formula for alcohol by weight is:

ABW = 76.08(OG-FG)/(1.775-OG).

alcohol by volume is:

ABV = ABW (FG/.794).


from here (http://www.realbeer.com/library/beerbreak/archives/beerbreak0301.php)

[paul84043]

Thanks!! That's great info to have..