1st all grain...broke hydrometer...sg question

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bctdi

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Well I just brewed my 1st all grain and after I took a sg reading of my wort which was 1.059 for 7.5 gallons...my hydrometer broke before I could check sg post boil, so can someone tell me if sg changes after the boil?According to my recipe my o.g should be 1.070.This was a 5 gallon batch w/ 14 lbs of grain.I ended up with 5 gallons after the boil , but I would like to figure my abv, and efficiency...should I just use me preboil sg reading?:confused:
 

Blender

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Yes the gravity goes up as the water evaporates out of the wort. I would go with what the software tells you and call it good. Consider getting a refractometer to take your gravities during the brew, they are nice, quick and easy.
 

BierMuncher

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Take out a couple cups of your post boil wort (before adding yeast) and stash in the fridge until you can get another hydrometer. Even if you added yeast, keeping it cold should retard fermentation.

I think it's reasonable that a 1059 beer moved pretty close to 1070 after a 2.5 gallon boil off.
 
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bctdi

bctdi

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Wow, thanks for the quick replies.It's too late to set aside some cause it's already in the fermentor, but I'll do that next time if my hyd brakes again.It's my third brew and my second broken hydrometer.What's with these freakin cheap ass hydrometers anyway???I need to find an unbreakable one.I checked the sg of the wort and got 1.046....and almost had a bird.I thought 14 lbs of grain should get me higher but then I remembered to adjust for the temp of my hot wort, then came up with 1.059.:)I appreciate the help, looks like this brew is gonna be just fine:D
 

Duckfoot

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It isn't so much the cheapness of said hydrometers, it is the fact that some of us -cough cough- are a little less than, shall we say gentle with delicate glass objects... Just stock up on two next time... You are sure to bust another one at some point...

:mug:
Good Luck!
 
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bctdi

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;)
It isn't so much the cheapness of said hydrometers, it is the fact that some of us -cough cough- are a little less than, shall we say gentle with delicate glass objects... Just stock up on two next time... You are sure to bust another one at some point...

:mug:
Good Luck!
point taken:mug:....note to self...protect the hydro at all costs.
 

BarleyWater

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If you have a hydrometer and a refractometer, you can take a reading with both when the beer is done and figure out what the OG and ABV are.
 

becksbolero2

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In my short brewing career I have spent more money on those F'ing hydrometers then I have on hops.......ridiculous
 

Ketchepillar

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Converting from pre-boil gravity to post-boil gravity should be a pretty straight forward math equation. gravity=concentration of sugars & stuff and you have 3 of 4 numbers, so just solve for the other. 7.5/5=1.5; 1.5*59=1.088. Note possible complications: wort occupies different volumes at different temps, so if your 7.5 and 5 gal figures are both at 212F then you're fine, otherwise you can adjust for that. Also, what temp did you take you're pre-boil reading at? If it was around 170F, then you need to adjust for that. But then I think you would have a ridiculously high SG, probably over 100% efficiency, so you must have cooled it. Anyways, keep those things in mind. Hope that helps.
 
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bctdi

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Converting from pre-boil gravity to post-boil gravity should be a pretty straight forward math equation. gravity=concentration of sugars & stuff and you have 3 of 4 numbers, so just solve for the other. 7.5/5=1.5; 1.5*59=1.088. Note possible complications: wort occupies different volumes at different temps, so if your 7.5 and 5 gal figures are both at 212F then you're fine, otherwise you can adjust for that. Also, what temp did you take you're pre-boil reading at? If it was around 170F, then you need to adjust for that. But then I think you would have a ridiculously high SG, probably over 100% efficiency, so you must have cooled it. Anyways, keep those things in mind. Hope that helps.
my preboil sg was 1.046 at a temp of 130 deg. f.so That's how I came up with 1.059.Of course the 5 gallons is what went into the fermentor, there might have been 1/2 a gallon or so of sludge left in the brewpot below the level of the outlet valve.
 

LooyvilleLarry

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If you have a hydrometer and a refractometer, you can take a reading with both when the beer is done and figure out what the OG and ABV are.
Could you elaborate on this? I just got a refractometer, and was under the impression that it isn't accurate once alcohol has been introduced.
 

XXguy

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I've never busted a hydrometer. I'd say cool the wort before dropping your thin glass hydrometer into the sample.

If you want to/need to check it hot - invest in a refractometer.
 

janzik

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Well I just brewed my 1st all grain and after I took a sg reading of my wort which was 1.059 for 7.5 gallons...my hydrometer broke before I could check sg post boil, so can someone tell me if sg changes after the boil?According to my recipe my o.g should be 1.070.This was a 5 gallon batch w/ 14 lbs of grain.I ended up with 5 gallons after the boil , but I would like to figure my abv, and efficiency...should I just use me preboil sg reading?:confused:
How are you boiling off 2.5 gallons?! How long are you boiling? Even on a 90 minute boil on my high BTU stove, 7 gallons only gets down to 5.5. Where are you losing that extra gallon?!
 

Munsoned

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Could you elaborate on this? I just got a refractometer, and was under the impression that it isn't accurate once alcohol has been introduced.
If you take a pre-fermentation reading with the refractometer, you can get an OG with some spreadsheet calculators that are floating around. Those calculators also allow you to take readings during and after the fermentation with the refractometer, and they will do the (fairly complex) math for you to tell you your current SG. You have to have a baseline at the beginning of the process to start from though...
 
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bctdi

bctdi

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How are you boiling off 2.5 gallons?! How long are you boiling? Even on a 90 minute boil on my high BTU stove, 7 gallons only gets down to 5.5. Where are you losing that extra gallon?!
I'm still trying to figure that out.My brew pot has some wort left after the boil below the outlet valve and I think there's some absorption from the hop bag...quite a bit actually, but I squeezed most of that back into the pot.I only boiled 60 minutes.This was my first ag and 3rd batch so I'm still trying to figure this stuff out.:).
 

BarleyWater

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If you take a pre-fermentation reading with the refractometer, you can get an OG with some spreadsheet calculators that are floating around. Those calculators also allow you to take readings during and after the fermentation with the refractometer, and they will do the (fairly complex) math for you to tell you your current SG. You have to have a baseline at the beginning of the process to start from though...
There is a calculation that will tell you the OG, given the FG reading from the hydrometer and refractometer, no other numbers needed.

I have a beer right now (Southern English Brown), the hydrometer is reading 1.014 and the refractometer is reading 6.0 Brix, if I put those two numbers into the equation (I'm using BeerSmith), is says my OG should have been around 1.040, when in fact it was 1.041. Pretty close if you ask me, and no numbers aside from post fermentation numbers needed.
 

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