my FG seems ... TOO low ...

[justenoughforme]

brewgr gives me an estimated 1.019 and 1.017 on the two batches i'm ready to bottle.

both are steady a 1.004 and 1.006

using white labs WPL550. (monastery yeast).

i'm no yeast expert but this seems like impossibly high attenuation.

both left about three weeks in a 63 degree concrete hole.


so what's causing my final gravity to be so low ? my hydrometer is close to spot on (not 0.004 off... let alone 0.015). is this yeast just THAT much better than brewgr calculated ?

 

[TheMadKing]

brewgr gives me an estimated 1.019 and 1.017 on the two batches i'm ready to bottle.

both are steady a 1.004 and 1.006

using white labs WPL550. (monastery yeast).

i'm no yeast expert but this seems like impossibly high attenuation.

both left about three weeks in a 63 degree concrete hole.


so what's causing my final gravity to be so low ? my hydrometer is close to spot on (not 0.004 off... let alone 0.015). is this yeast just THAT much better than brewgr calculated ?

what were your recipe, OG, boil time etc?

 

[porterpounder]

That yeast is a beast. If you used sugar in the recipe it will often go that low easily. If not, it's still a possibility.

 

[justenoughforme]

both were basic extract recipes, only difference being the type of specialty grain (chocolate malt vs crystal 60)

9 lbs LME
1Lb dextrose
.5 lb specialty grains (1 lb for the other batch.)

60 minute boils, both with bittering hops at 60 min to aim for 50 IBU's. one with citra dry hopped.

brewgr estimates:
OG1.075
FG1.019


but my FG is way way way lower. unreasonably so.

 

[justenoughforme]

my calculations show i was aiming for 7.2% alcohol ... and i got close to 9%.

 

[TheMadKing]

both were basic extract recipes, only difference being the type of specialty grain (chocolate malt vs crystal 60)

9 lbs LME
1Lb dextrose
.5 lb specialty grains (1 lb for the other batch.)

60 minute boils, both with bittering hops at 60 min to aim for 50 IBU's. one with citra dry hopped.

brewgr estimates:
OG1.075
FG1.019


but my FG is way way way lower. unreasonably so.

I would guess its that pound of dextrose, like porterpounder said, its the added sugar and that yeast strain. It'll feed the yeast like crazy and you just ended up with a bit dryer beer than you intended. I wouldn't call that a problem though!

 

[justenoughforme]

even flat and warm, it tasted good ... noticeably hot but i know that subsides.

 

[Rockn_M]

I kinda think that brewgr underestimated the FG. WPL550 has 78%-85% attenuation.

 

[justenoughforme]

I kinda think that brewgr underestimated the FG. WPL550 has 78%-85% attenuation.

but 1.004 is like 93% attenuation. that's unreasonable, right ?

 

[Rockn_M]

The 78%-85% are just averages. You added a lot of dextrose which I bet the yeast went crazy for. I've had about 94% once with a very high OG.

 

[Rockn_M]

but 1.004 is like 93% attenuation. that's unreasonable, right ?

Also you might want to check the accuracy of your hydrometer. Sometimes the piece of paper slips a bit.

 

[justenoughforme]

yeah i have seen my hydro. off by 0.004 in water.


guess when you add it all up, nothing is amiss, it's just a culmination of hydro off a little bit, brewgr underestimating a little bit ... and have a REALLY healthy yeast colony. and, some of it being dextrose helps too.


now what am i going to do with all this 9% beer ?! ...guess i'll cellar most of it.

 

[Rockn_M]

now what am i going to do with all this 9% beer ?!

I wouldn't try and drink it all in one sitting.

 

[Black Island Brewer]

OP, how did this turn out after bottling and aging?