Low Original Gravity Issue

Sat Feb 07, 2009 3:16 pm

I just brewed my second batch of homebrew -- an imperial coffee stout -- in the hope of creating a tasty brew with a high apv. However, according to my hydrometer, my original gravity is only 1.061 at 70%, which seems impossibly low to me. Before brewing, I used the calculator on hbd.org to calculate a potential original gravity. Here's an outline of the recipe:

1 lb. munich
1/2 lb. American chocolate
1/2 lb. black patent
1/2 lb American 75L

9 lbs. ultralight LME
1/2 lb. light DME
1 lb. brown sugar

So, here's the question: why is my original gravity so low? As I said, this is only my second batch of brew, so I'm still learning the ropes. This phenomenon occurred with my first batch as well -- an IPA -- that was supposed to be between 1.046-1.057, but had an OG of 1.031 for me. What am I doing wrong?

Thanks for the help.
abrewick
 
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Re: Low Original Gravity Issue

Sat Feb 07, 2009 5:20 pm

There are a couple things that you could be doing wrong and it probably has everything to do with how you take your hydrometer measurement. If you got a reading of 1.061 and you were at 170 degrees F that is actually 1.087 (calculated from beer recipator) at 60 degrees so you were actually right on. If you are doing a partial boil and then topping up your fermenter with water you need to make sure you have the water mixed in really well because if you don't mix it the heavy wort will wink to the bottom and you will measure the lightweight stuff on top. You should also be making 5 gallons and not 6 or 7. That would thin out your beer as well. Check your hydrometer by putting it in a container of tap water at room temperature and seeing if it reads about 1.000. Check your thermometer by putting it in ice water to make sure it reads about 32 degrees F. I had a thermometer that was off by 10 degrees once. Also measure out 5 gallons of water into your fermenter and make sure you are filling up to that line and not past it.
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ziggy
 
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Location: Durham, NC

Re: Low Original Gravity Issue

Sun Feb 08, 2009 12:52 am

Ziggy,

Thanks for your response. I will definitely check both my hydrometer and thermometer for accuracy. It is entirely possible that my sample was diluted, since I had just added the wort into 2 gallons of cold water. I'll take another hydrometer reading when I remove the blow off tube and check for a discrepancy.

Many thanks.
abrewick
 
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Joined: Sat Feb 07, 2009 3:00 pm

Re: Low Original Gravity Issue

Mon Feb 09, 2009 9:25 am

Wanted to weigh in on this because I have had the same hydrometer troubles.

Although we all like to know our gravities and such, I wouldn't risk the infection when you go from blow-off to airlock. You will get a gravity reading, but it won't be your OG anyway. My feelings on this are as follows:

1. You used extract for your fermentables, so as long as your water was measured correctly you can assume your OG pretty darn close to what you calculated, if your calculations were correct.
2. Trying to take a sample will only risk infection and not really give you any useful information.
3. Let it finish out, take an FG to make sure it is ready to bottle, and estimate your ABV from your FG and estimated OG.
4. Chalk it up to practice and learning more about how to use your equipment!
5. RDWHAHB! It's a process of learning and you'll get great with practice.
6. Your beer will be beer, and as long as it's not infected it will be drinkable.

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Neuron_Theory
 
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Location: Rochester, Minnesota

Re: Low Original Gravity Issue

Mon Feb 09, 2009 8:47 pm

+1 on the estimated OG. I haven't extract brewed in a long time and forgot about that. You can pretty much assume your OG is what you calculate plus a few points for the steeping grains.
-"You want a beer?"
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ziggy
 
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