Why does my gravity aways seem to be off?

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

Bulls Beers

Supporting Member
HBT Supporter
Joined
Sep 15, 2007
Messages
3,290
Reaction score
175
Never fails. Either I'm off on my OG or FG. I just brewed a Pilsner, my OG was suppose to be Between 1.040-1.042. Mine was 1.052. I've done 8 batches so far and most of my finish gravites never hit it's target. usually off by 4-6 points.

Any suggestions?
 

DeathBrewer

Maniacally Malty
HBT Supporter
Joined
Apr 9, 2007
Messages
21,787
Reaction score
317
Location
Oakland, CA
could be volume...make sure for a five gallon batch you are EXACTLY at five gallons.

for most extract brewers the problem is that the sugars settle so you don't get a good reading. you need to mix it thoroughly just before you take the sample so you don't get a diluted sample or a sample with a heavy mix of sugars.

if you ARE doing extract, i would just go with the projected gravity and trust it...it will have exactly how much sugar you put into it.

EDIT: Final gravity can depend entirely on yeast attenuation, ingredients, mashing temperatures and a number of other things. you generally did not get anywhere near my projected FG when making extract batches. as long as it doesn't taste too sweet, you're in your attenutation range (usually ~70%) and there is no activity for several days, you are ready for the next stage.
 

Surly

Well-Known Member
Joined
Dec 10, 2007
Messages
989
Reaction score
90
Location
Prairie Farm
Have you checked your hydrometers accuracy?

Using distilled water at 60F it should read 1.000.
 
OP
OP
Bulls Beers

Bulls Beers

Supporting Member
HBT Supporter
Joined
Sep 15, 2007
Messages
3,290
Reaction score
175
DeathBrewer said:
could be volume...make sure for a five gallon batch you are EXACTLY at five gallons.

for most extract brewers the problem is that the sugars settle so you don't get a good reading. you need to mix it thoroughly just before you take the sample so you don't get a diluted sample or a sample with a heavy mix of sugars.

if you ARE doing extract, i would just go with the projected gravity and trust it...it will have exactly how much sugar you put into it.

EDIT: Final gravity can depend entirely on yeast attenuation, ingredients, mashing temperatures and a number of other things. you generally did not get anywhere near my projected FG when making extract batches. as long as it doesn't taste too sweet, you're in your attenutation range (usually ~70%) and there is no activity for several days, you are ready for the next stage.

Yes. I'm doing extract batches. I brewed with 2 gallons and added 3 1/2 in the primary for any water loss.
 

malkore

Well-Known Member
Joined
Jun 15, 2007
Messages
6,924
Reaction score
56
Location
Nebraska
partial boil extract batches take at least 10 minutes of constant stirring to become a homogenous mixture.

so, your hydrometer samples aren't diluted for your OG reading, and they come out thicker than they should, and thus a higher OG reading.

if you're following an extract recipe and you top off to 5 gallons, you cannot miss your OG range....just assume its correct.

For FG readings, those are accurate as long as your hydro is calibrated and you're adjusting for temperature differences. your FG should be close to what the recipe states. a couple points either way is no big deal. if you're off by 10-20 points...somethings up...probably a stuck/stalled fermentation.
 

mrfocus

Well-Known Member
Joined
Oct 3, 2007
Messages
573
Reaction score
3
Location
Montreal, Canada
Temperature could be another factor. At 68F (if your hydrometer is calibrated for 60F) you have 2 points difference right there.
 

GIusedtoBe

Well-Known Member
Joined
Jul 6, 2007
Messages
428
Reaction score
3
Location
Knoxville TN
malkore said:
if you're following an extract recipe and you top off to 5 gallons, you cannot miss your OG range....just assume its correct.

I have to disagree with this partially because I've had a lot of extract batches that are off the mark on the OG. I think a lot of recipes expect more gravity points than the malt extract can deliver. A good example is in Clone Brews where you have one recipe w/ an SG of 1.052 w/ 6# of DME and then another recipe with a range of 1.056 to 1.060 with the same 6# of DME.

Now I always try to plus up the extract by a small amount and I always hit the OG but sometimes I do come out with a slightly stronger beer. I did a Red Hook ESB clone and it came in at 1.060 so it will be a little stronger than the real deal.:drunk: :tank: :mug:

Regards,
Al
 

DeathBrewer

Maniacally Malty
HBT Supporter
Joined
Apr 9, 2007
Messages
21,787
Reaction score
317
Location
Oakland, CA
i wouldn't trust anything clone brews says. you can make some good beer with their recipes, but it'll never be on mark with what you're trying to clone. it's more a "learn the style" book.

volume is key, too. pour 1 gallon at a time into your fermentation vessel and make marks all the way. i make a 5.25 and 5.5 gallon mark, too. that way, i can always be spot on with my gravity and if i need to add water to drop it, i can.

and yeah, mix the s*** out of it before you take a sample.

and no, you will CAN NOT miss your OG range if you have the correct volume and the correct amount of sugars/extracts. the only thing that could be wrong is your recipe specifications, unless a mistake was made in the process.

:mug:
 

Dycokac

Well-Known Member
Joined
Sep 18, 2007
Messages
237
Reaction score
0
Location
Grand Rapids, MI
DeathBrewer said:
...volume is key, too. pour 1 gallon at a time into your fermentation vessel and make marks all the way. i make a 5.25 and 5.5 gallon mark, too. that way, i can always be spot on with my gravity and if i need to add water to drop it, i can.

...

I finally marked 5 gallons on one of my 5 gal and my 6.5 gal carboys I'll add the extra gallon marks when mine become free :). After reading way off on the 8-8-08 RIS, i way watered it down in my 6.5 gal carboy :(

Next step, i need to get myself something better than a 2 quart plastic pitcher to measure out water. I'm hopeing in March to get a bigger brew pot though, so i can start doing full boils and that should correct any top off/mix OG reading errors :).
 

TexLaw

Here's Lookin' Atcha!
HBT Supporter
Joined
Sep 19, 2007
Messages
3,672
Reaction score
37
Location
Houston, Texas
DeathBrewer said:
i wouldn't trust anything clone brews says. you can make some good beer with their recipes, but it'll never be on mark with what you're trying to clone. it's more a "learn the style" book.

Man, I sure do agree with that 100%. Clone Brews was a real disappointment when I first looked at it.


TL
 

david_42

Well-Known Member
Joined
Oct 8, 2005
Messages
25,581
Reaction score
193
Location
Oak Grove
Hard to beat gallon milk jugs for measuring water. Profit margins and government regulations being what they are, the dairy industry is very precise in their production. If a 2 quart pitcher is off by 3 ounces, your gravities would be off by 10% either way.

LME does vary, both in sugar content and fermentability. DME has a more consistent sugar content from one manufacturer to another, but fermentability will still vary.
 

GIusedtoBe

Well-Known Member
Joined
Jul 6, 2007
Messages
428
Reaction score
3
Location
Knoxville TN
TexLaw said:
Man, I sure do agree with that 100%. Clone Brews was a real disappointment when I first looked at it.


TL

Hey Tex, I've found this out the hard way but do you know of a good recipe book for us novice types? I make the SNPA "Clone Brews" recipe regularly but I do tweak it a bit. It really does'nt taste like Sierra but it does make a very good PA.

Regards,
Al
 
OP
OP
Bulls Beers

Bulls Beers

Supporting Member
HBT Supporter
Joined
Sep 15, 2007
Messages
3,290
Reaction score
175
My thinking is I didn't mix it very well. I added 3 gallons of water to my primary. i then added the wort after it cooled.
 
Top