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Old 06-26-2009, 12:02 AM   #1
adslania
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Default Best way to obtain original gravity?

Hello everyone,

I'm on my sixth extract batch right now and have ordered from a couple of different online homebrew suppliers. It seems that every one of them has a different method for obtaining the gravity of the wort, whether it's to be obtained when pitching the yeast or slightly before pitching the yeast. I'm using a plastic fermentation bucket and I would assume if I used a carboy as a primary that I could just leave the hydrometer in the carboy to record gravity.

My current set up is a plastic fermentation Ale Pail for the primary and a Better Bottle for the secondary. What is the best way to obtain a starting and final gravity to determine ABV?

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Old 06-26-2009, 12:07 AM   #2
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Get your starting gravity by pulling a small sample right before pitching. After your airlock has stopped bubbling, wait 1-2 days and then take a hydrometer reading. Close the lid and do the same thing for 3 days. Once the gravity is steady for 3 days in a row, write down that number as your FG. You can then use the OG and FG that you have written down to determine the final ABV% of your beer.

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Old 06-26-2009, 12:21 AM   #3
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Originally Posted by rsmith179 View Post
Get your starting gravity by pulling a small sample right before pitching. After your airlock has stopped bubbling, wait 1-2 days and then take a hydrometer reading. Close the lid and do the same thing for 3 days. Once the gravity is steady for 3 days in a row, write down that number as your FG. You can then use the OG and FG that you have written down to determine the final ABV% of your beer.
Yep.....I've never heard of ANY dispute as to when you draw your sample...you do it before you pitch the yeast, then you add the yeasites and seal up the fermenter. With powdered or liquit yeast floating on the surface you'd get a messy sample.

Now the greater debate would be whether you did it before or after aeration. My experience has been that it is easier to read if you draw you sample before aerating the wort.

The problem with extract batches that are not full boil is that it is nearly impossible to integrate the wort and top of water without vigorously stirring it, which will introduce a ton of foam and make the sample difficult to read...Also sometimes even the most vigorous mixing still results in incomplete mixing (though it does all mix during fermentation.)

You will see a lot of threads from first time brewers thinking they did something wrong because their readings were so off. The good thing about extract brewing is that hitting your og is nearly foolproof, as long as you topped off to the right final volume. (Most recipes are for 5 gallons, though some are for 6...so you have to make sure you top off to the correct amount.) It is gaurenteed then that if you followed directions and topped off correctly, that you will be at your target starting gravity.

ANd if your recipe doesn't state what it should be, you can calculate the OG of an extract batch easily with any software, including free-ones like beer calculus...just imput all the ingredients and the final volume, and it will tell you what the gravity is....
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Old 06-26-2009, 01:01 AM   #4
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I would not leave the hydrometer in the fermenter, glass or plastic. It'll get all gunked up and give false readings anyhow. Take a sample, read it and discard it. You can drink it if you like. I do sometimes. I do NOT pour the sample back.

David

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Old 06-26-2009, 01:27 PM   #5
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OG: Directions will vary in this regard, because it doesn't matter.

FG: Much better to leave the hydrometer in the sample tube with the original sample. You can even setup a webcam and watch it ferment when things are slow at work.

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Old 06-26-2009, 01:32 PM   #6
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OG: Directions will vary in this regard, because it doesn't matter.

FG: Much better to leave the hydrometer in the sample tube with the original sample. You can even setup a webcam and watch it ferment when things are slow at work.
I have never left my beer in the hydro tube but this could definately work just fine. A lot of bigger breweries take hydro samples for the OG and let those samples ferment out and just take hydro readings off of the sample. I would only suggest that if you do use this method, make sure that the hydro sample is in the same area as your primary. If you leave the sample somewhere cooler or warmer than your primary, the fermentation rates will not match up.

Also, just remember that this sample has been exposed to air for quite a while if you keep it until the end. Just don't throw that sample back into your batch when finished!!
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Old 06-26-2009, 02:18 PM   #7
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I have never left my beer in the hydro tube but this could definately work just fine. A lot of bigger breweries take hydro samples for the OG and let those samples ferment out and just take hydro readings off of the sample. I would only suggest that if you do use this method, make sure that the hydro sample is in the same area as your primary. If you leave the sample somewhere cooler or warmer than your primary, the fermentation rates will not match up.

Also, just remember that this sample has been exposed to air for quite a while if you keep it until the end. Just don't throw that sample back into your batch when finished!!
If you are talking about a satellite...that will not telly you WHEN the beer is done, only What the final gravity will be....4 ounces and 5 gallons are not going to ferment out at the same pace....

OP for you grav readings, don't panic, just sanitize and draw your samples as needed, then drink them...
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Old 06-26-2009, 03:57 PM   #8
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Originally Posted by Revvy View Post
Yep.....I've never heard of ANY dispute as to when you draw your sample...you do it before you pitch the yeast, then you add the yeasites and seal up the fermenter. With powdered or liquit yeast floating on the surface you'd get a messy sample.

Now the greater debate would be whether you did it before or after aeration. My experience has been that it is easier to read if you draw you sample before aerating the wort.

The problem with extract batches that are not full boil is that it is nearly impossible to integrate the wort and top of water without vigorously stirring it, which will introduce a ton of foam and make the sample difficult to read...Also sometimes even the most vigorous mixing still results in incomplete mixing (though it does all mix during fermentation.)

You will see a lot of threads from first time brewers thinking they did something wrong because their readings were so off. The good thing about extract brewing is that hitting your og is nearly foolproof, as long as you topped off to the right final volume. (Most recipes are for 5 gallons, though some are for 6...so you have to make sure you top off to the correct amount.) It is gaurenteed then that if you followed directions and topped off correctly, that you will be at your target starting gravity.

ANd if your recipe doesn't state what it should be, you can calculate the OG of an extract batch easily with any software, including free-ones like beer calculus...just imput all the ingredients and the final volume, and it will tell you what the gravity is....
Thanks for the feedback everyone. I took the OG for a Red Wheat I recently brewed and it was right on point according to the directions from AHS. I took the OG for the Belgian 12 from AHS a couple of days ago and it was WAY off. I'll try this out with the Belgian once the vigorous fermentation stops, which has been going on for almost 3 days straight now.

Thanks again!
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