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General Category => General Homebrew Discussion => Topic started by: bono_loves_beer on September 11, 2010, 08:16:07 PM

Title: Nervous about my original gravity...
Post by: bono_loves_beer on September 11, 2010, 08:16:07 PM
Hey all, just trying to ease my own worst fears here. I'm brewing my first IPA and I've pitched the yeast and everything, but before I did so, like a good homebrewer I measured my OG. It's sitting right now around 1.012 - much lower than expected. I hope I didn't spend 1 1/2 hours brewing for just some cold yeasty water... and I feel like my hydrometer is mocking me. Any explanations?
Title: Re: Nervous about my original gravity...
Post by: jeffy on September 11, 2010, 08:32:38 PM
Was this an extract or all-grain batch?  How much malt?
Title: Re: Nervous about my original gravity...
Post by: svejk on September 11, 2010, 08:42:22 PM
We will need to know your recipe to get a better idea of what happened. If this was a beer where you boiled only portion of the wort and then diluted it with water, it might be something as simple as a batch that didn't get mixed well enough. It would also help to know how much total water you used, and the process of how you went about making the beer.
Title: Re: Nervous about my original gravity...
Post by: rbclay on September 11, 2010, 09:41:04 PM
Yes... more info please. 1012 is more like an FG than an OG. I made many extract batches in the beginning that had  completely off hydrometer readings. Several reasons...
Title: Re: Nervous about my original gravity...
Post by: tschmidlin on September 11, 2010, 10:14:18 PM
Yeah, I'd look at mixing as the issue, especially if you late extract.  Even my friends who mashed with unmilled grain got better than 1.012.
Title: Re: Nervous about my original gravity...
Post by: tubercle on September 12, 2010, 12:23:34 AM
...and check the hydrometer calibration with plain water.
Title: Re: Nervous about my original gravity...
Post by: bono_loves_beer on September 12, 2010, 03:02:35 AM
We will need to know your recipe to get a better idea of what happened. If this was a beer where you boiled only portion of the wort and then diluted it with water, it might be something as simple as a batch that didn't get mixed well enough. It would also help to know how much total water you used, and the process of how you went about making the beer.

I used the following in my recipe:

5.5lb amber malt extract
1lb crystal (20c)
1/2lb roasted
Northern hops (boiling)
Cascade hops (finishing)
gypsum

I did this outdoors on a turkey fryer.

In 1.5gal water, boiled my cracked grains for 30 min, then removed majority of the grains (my strainer's not that good and I didn't have any cheesecloth for steeping). Added the extract, Northern, and gypsum for 60min, and finished last min with Cascade. Sparged into to ~2gal water, topped off to 5gal, allowed to cool to 70 degF, pitched yeast, took the OG, then panicked and came to AHA forums.

When I added the wort to the carboy, I didn't intentionally "mix" it persay, just siphoned in the water to top off the carboy. Maybe it was still in a suspension with the wort when I siphoned off for my OG reading. If this is the reason it was so low, 1) how would I mix it next time, and 2) is there any way to find abv without an accurate OG reading? I'm pretty much without one for this batch. Thanks for the help all.
Title: Re: Nervous about my original gravity...
Post by: bonjour on September 12, 2010, 04:43:50 AM
I used the following in my recipe:

5.5lb amber malt extract
1lb crystal (20c)
1/2lb roasted
Northern hops (boiling)
Cascade hops (finishing)
gypsum

I did this outdoors on a turkey fryer.

In 1.5gal water, boiled my cracked grains for 30 min, then removed majority of the grains (my strainer's not that good and I didn't have any cheesecloth for steeping). Added the extract, Northern, and gypsum for 60min, and finished last min with Cascade. Sparged into to ~2gal water, topped off to 5gal, allowed to cool to 70 degF, pitched yeast, took the OG, then panicked and came to AHA forums.

When I added the wort to the carboy, I didn't intentionally "mix" it persay, just siphoned in the water to top off the carboy. Maybe it was still in a suspension with the wort when I siphoned off for my OG reading. If this is the reason it was so low, 1) how would I mix it next time, and 2) is there any way to find abv without an accurate OG reading? I'm pretty much without one for this batch. Thanks for the help all.
Most likely you have stratification and you are fine, but . . . . . .

as a ROT you do NOT want to boil grains (unless you are doing a decoction). 
Title: Re: Nervous about my original gravity...
Post by: euge on September 12, 2010, 05:14:25 AM
But it'll probably be OK, albeit a little dry on the tongue.

Mix-stir and a drill for the carboy.
Title: Re: Nervous about my original gravity...
Post by: Robert on September 12, 2010, 06:08:16 AM
But it'll probably be OK, albeit a little dry on the tongue.

Mix-stir and a drill for the carboy.

Screw mix-stir   :D,  Take a platsic clothes hanger, cut it into a long "J" and use it. Fits right into a carboy.
Title: Re: Nervous about my original gravity...
Post by: euge on September 12, 2010, 06:21:35 AM
That'll work too! :D Cheap and easy.
Title: Re: Nervous about my original gravity...
Post by: svejk on September 12, 2010, 07:54:26 AM
I agree that your OG issue is probably related to insufficient mixing.  Since it looks like the wort may not have been very well mixed, I'm also concerned whether it has been properly aerated.  Once the wort has been cooled, it needs to be aerated because the yeast need oxygen to reproduce so they can do the job that we are asking them to do.  The standard procedure is to put the cooled wort into a carboy and shake the heck out of it for a few minutes until it is really foamy.  This is the only point in beer making where you want to add oxygen to the beer.  After fermentation has finished, you want to avoid adding oxygen.

If you think you are going to like brewing, I highly recommend that you buy brewing software.  I use Promash, but there are others on the market.  You can input your recipe into them, and it will give you a pretty good estimation for what your gravity will be.  When I put your recipe into Promash, it says that your OG is 1.048.  That's probably a reasonable estimate for this batch.
Title: Re: Nervous about my original gravity...
Post by: bono_loves_beer on September 12, 2010, 01:04:03 PM
euge: ...but it'll probably be OK, albeit a little dry on the tongue.

Any specific reason for that dryness? Is it due to my pseudo-decoction mash?

bonjour: Most likely you have stratification and you are fine, but... as a ROT you do NOT want to boil grains (unless you are doing a decoction).

Duly noted. I need to invest in a good brew-pot thermometer so I can avoid overheating the wort unintentionally. It also was my first experience with the turkey fryer, which conveniently had a 15-minute-autoshutoff regulator attached to the gas tank, and it cost me precious minutes of heat when I couldn't reset the timer in time. So maybe I was overcompensating. Good thing I have leftover summer ale to get me through this batch.

svejk: Once the wort has been cooled, it needs to be aerated because the yeast need oxygen to reproduce so they can do the job that we are asking them to do.

That makes so much sense it's worrying that a trained BiochemEng didn't realize on his own. I'll be sure to aerate next time. *facepalm*
Title: Re: Nervous about my original gravity...
Post by: euge on September 12, 2010, 03:24:18 PM
There is a potential for tannin extraction from the grain when boiled like that, and the 2.66 qt/# is a little thin (IMO) for a decoction mash. Tannin extraction has never happened to me when I've done decoctions, however they've been fairly stiff with less than a quart per pound.

If "steeping" was your intent the grain should soak like a teabag anywhere from 150F up to 170F for 30 or more minutes. Still- you should be just fine.

Recipe looks good though not sure if you needed the gypsum. Changes to you water chemistry shouldn't be done blindly; but only after you have knowledge of your water's chemistry profile. This report is most likely available from your water utility. Ward labs can also analyze your water for you.

Read this:

http://www.howtobrew.com/section1/chapter4.html (http://www.howtobrew.com/section1/chapter4.html)

http://www.howtobrew.com/section3/chapter15.html (http://www.howtobrew.com/section3/chapter15.html)

If you like what you saw be sure to buy Palmer's 3rd edition of How To Brew. A very handy book to have.
Title: Re: Nervous about my original gravity...
Post by: svejk on September 12, 2010, 05:51:49 PM
I'll be sure to aerate next time. *facepalm*

Since you just brewed this beer yesterday, are there any signs of fermentation yet?  If not, I would go ahead and aerate it now.  My understanding is that it is okay to add oxygen up until fermentation is halfway done, although it is normally only done once at the beginning.
Title: Re: Nervous about my original gravity...
Post by: tschmidlin on September 12, 2010, 06:15:40 PM
Just give it some really vigorous shakes - if the yeast aren't fermenting, there will be air in the headspace that the yeast can use.  If they are fermenting, the headspace will be more or less purged already and shaking won't cause any problems.

What yeast did you pitch, and how much?  Dried/liquid, if dry how many grams was the package?