Low initial specific gravity

Sun Mar 09, 2014 5:47 pm

I brewed a hefeweizen today with a target initial gravity of about 1.050. It was an extract brew (6 lbs LME) with about 8 oz of carapils steeping grains. I ended up with about 5.5 gallons in the fermenter. However, when I took the initial specific gravity it was much lower than I was expecting coming in at 1.041 at 64 degrees Fahrenheit.

Is there anything I could or should do at this point to raise the gravity? Is this something I should even be worried about?

thanks, Paul
pjdececco
 
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Re: Low initial specific gravity

Sun Mar 09, 2014 6:24 pm

Let's do some math to figure out exactly what you have here:

Welcome-

Using expected gravity amount from your fermentables:

44pppg dme x 6 lbs = 264
20pppg carapils x 1.2 = 10
274 gravity points / 5.5 gallons = 49.8181 ==> 1.050 expected OG, at a volume of 5.5 gallons.

So, either you threw out 18% of your fermentables or you have something else going on. I doubt you lost that much due to boilover, so let's look further.

A common newbie mistake is to forget to stir the wort well before you take the sample. The wort stratifies (heavy stuff on the bottom, light stuff on top) and when you draw off the top, the sample measures low.

I bet that you didn't stir it up very much just before you took your sample.
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BDawg
 
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Re: Low initial specific gravity

Mon Mar 10, 2014 6:58 am

Nice thing about extract brews is that if the recipe says you have 1.050 and you have the right volume it's gonna be 1.050 don't even need to measure OG. and it's gong to be really really hard to get it all mixed well enough to get an accurate reading right now anyway.
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morticaixavier
 
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Re: Low initial specific gravity

Mon Mar 10, 2014 2:02 pm

Note the OP stated LME...
Assuming 37 gravity points from LME:
37pppg lme x 6 lbs = 222
20pppg carapils x 0.5 = 10
232 gravity points / 5.5 gallons = 42.1818 ==> 1.042 expected OG, at a volume of 5.5 gallons.

Seems like the measured OG of 1.041 was pretty close to what should be expected for that volume.

I wouldn't worry about trying to raise the gravity at this point. Just ferment it well and hopefully enjoy the beer by the liter!
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JoeBeer100
 
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Re: Low initial specific gravity

Mon Mar 10, 2014 3:25 pm

Thanks to all of your quick responses. I really appreciate the time and advice.
pjdececco
 
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Re: Low initial specific gravity

Mon Mar 10, 2014 4:37 pm

Beersmith says 1.039.........
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Kbar
 
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Re: Low initial specific gravity

Mon Mar 10, 2014 6:22 pm

Great catch, Joe. You are absolutely right. I did the math for DME, not LME.

Different brands of LME will have different values, nearly all in the range of 1.035-1.037.
Regardless, that OG is right in the ballpark.

Honestly, I'd leave it alone. Next time, check your recipe formulation and ensure that it is slated for 5.5 gallons instead of 5, in which case you can increase everything by 10% or just add DME at the rate of 9 OG pts per lb in 5 gallons to hit the target gravity.
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Re: Low initial specific gravity

Mon Mar 17, 2014 11:54 am

BDawg wrote:Great catch, Joe. You are absolutely right. I did the math for DME, not LME.

Different brands of LME will have different values, nearly all in the range of 1.035-1.037.
Regardless, that OG is right in the ballpark.

Honestly, I'd leave it alone. Next time, check your recipe formulation and ensure that it is slated for 5.5 gallons instead of 5, in which case you can increase everything by 10% or just add DME at the rate of 9 OG pts per lb in 5 gallons to hit the target gravity.


Late to the party, been busy lately. I would also wonder if you're getting all the sugars out of the carapils just steeping them. You could easily lose some points there as well.
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