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Preboil gravity reading

PostPosted: Thu Jan 15, 2009 7:44 am
by thebuddrik
I have never taken them before but before would like to try for my next brew. My question is can you use a hydrometer or is the high temp. too much? Can I just float it in my kettle, before I bring it up to a boil, or do I need to put some in my testing tube and let it cool?
Thanks guys

PostPosted: Thu Jan 15, 2009 10:04 am
by redtail28
For a hydrometer to be accurate the temp needs to be around
60 to 62 and then use a correction cart to dead on.
I think that floating it inside your brew pot pre boil
Has several draw backs
1. How are going to see it may be hard to read.
2. It may crack and then you’re screwed.
3. You’re going to get a wrong reading
Cool a small amount of wort pre boil to get your
Reading, then you can put back the sample
Back to be boiled.

That my 2 cents 8)

PostPosted: Thu Jan 15, 2009 12:48 pm
by aleguy
I agree with Redtail. Though I don't know why you would bother with a pre-boil reading unless you're a total efficiency wonk.

PostPosted: Thu Jan 15, 2009 1:04 pm
by thebuddrik
It is going to be my first time using my equipment and I want to see where I stand.

PostPosted: Thu Jan 15, 2009 2:17 pm
by yeastmeister
Easy, stir the kettle up prior to taking your reading to make sure the initial runnings and the sparge running are mixed. Thats what makes your pre-boil gravity up.

Take a sample to measure, put it in a mason jar, or something, seal it up and run water over it till it cools. Or just let it sit around. Take a reading whenever it gets around 60F. No rush if your just trying to see where you are.

PostPosted: Thu Jan 15, 2009 11:47 pm
by Imakewort
Hydrometer's are nice really accurate, but a little pain to use. I am including a link to Palmer's website on brewing about the use of a hydrometer. . I mainly use mine to check to see when primary fermentation is finished. For all my pre boil and post boil gravity checks I use a refractometer, It only uses 1 drop of wort and is temperature correcting, and extremely fast. As yeastmaster said you must stir your wort because it will stratify and give a very inaccurate reading. Here is a link about using a refractometer.

[url]http://morebeer.com/learn_vids/vids_refract
[/url]http://www.howtobrew.com/appendices/appendixA.html

PostPosted: Fri Jan 16, 2009 11:07 am
by aleguy
I like refractometers, but the readings have to be converted. I believe the standard is to multiply by 4 and put the result in the last two decimal places. (20 Brix =1.080 S.G.)
The only problem with a refractometer really comes in if you have a gravity that exceeds its capacity to measure dissolved sugar. If you wanted to say, brew a beer of 22% alcohol, the refractometer would not be able to measure that much sugar.