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hookturn 07-16-2010 10:14 PM

beer is not fermenting
 
I put up a pilsner Urquell, boiled the mash by accident but it still has good smell and taste, partial grain. It's been 5 weeks and the spec gravity is 1.012
this is according to the gauge about 2.5% alchohol. What do you think went wrong. I used a good pilsner yeast and when I transfered it to the secondary fermenter there was a lot of crud on top of the wort. I don't think if fermented. I sat and watched on day for about 2 hrs and only saw it bubble once. Is there anything I can do to bring it up? I think the Alc % should be around 5.
My first reading right after I put it in the fermenter was 1.042

ShortSnoutBrewing 07-16-2010 10:26 PM

Um...how can you say your beer isn't fermenting if you started at 1.042 and are at 1.012? Notice the 30 point difference? That means them there sugars are being gobbled up. You're a bit off on the 2.5% too. If I'm doing my math right that's about a 3.9%abv. That's about the best you're gonna get though. I think this brew normally has an OG in the upper 1.050's. What temps are you fermenting at?

SumnerH 07-16-2010 10:27 PM

Quote:

Originally Posted by hookturn (Post 2165229)
I put up a pilsner Urquell, boiled the mash by accident but it still has good smell and taste, partial grain. It's been 5 weeks and the spec gravity is 1.012
this is according to the gauge about 2.5% alchohol. What do you think went wrong. I used a good pilsner yeast and when I transfered it to the secondary fermenter there was a lot of crud on top of the wort. I don't think if fermented. I sat and watched on day for about 2 hrs and only saw it bubble once. Is there anything I can do to bring it up? I think the Alc % should be around 5.
My first reading right after I put it in the fermenter was 1.042

If you overheated the mash it wouldn't be too surprising to get a less fermentable wort. What yeast are you using? What temp are you fermenting at?

The good news is that going from 1.042 to 1.012 means that you're sitting at 4.0% ABV; still a bit low, but a lot better than your estimate.

EDIT: There's no "gauge" on a hydrometer that can tell you the ABV from a single reading. You need to know both the OG and the FG to figure ABV:
abw=76.08*(og-fg)/(1.775-og)
abv=abw*(fg/.794)

malkore 07-16-2010 10:29 PM

you cannot get the alcohol reading from the final gravity alone. You use the OG and FG, and the difference tells you how much sugar was replaced with alcohol.

that ABV that some hydros have on them is the estimated potential gravity, and you read it when you take the OG only (it assumes 70% attenuation to make this estimate)

I'd also recommend more reading on your part...it seems like you're not quite comfortable with the basics of brewing and fermentation, so start with building your core education of brewing first and foremost. www.howtobrew.com is good online snippet of the real book, which i HIGHLY recommend.

Yooper 07-16-2010 10:33 PM

Well, if it went from 1.042 to 1.012, it's finished!

The hydrometer isn't an alcohol meter. It measure the amount of sugars in a solution. Since the sugars started at 1.042, and finished at 1.012 (a typical finishing gravity for beer), that's good.

If you really want to figure the alcohol % by volume, the formula is:

(OG-FG) x 131 = ABV

So,
(1.042- 1.012) x 131= 3.93%

Fermentation doesn't take long- maybe a few days. Most lagers are fermented cold, so it might take a bit longer if that's the case. Most of my lagers are done in about 10 days, most of my ales are finished in about 3-5 days. That doesn't mean I bottle then- even when it's done fermenting, the yeast are working to "clean up" the by products of fermentation.

What I'm trying to say in my long winded reply is the beer is finished! Bottle it!

BeerJorge 07-16-2010 11:05 PM

Quote:

Originally Posted by YooperBrew (Post 2165261)
Well, if it went from 1.042 to 1.012, it's finished!

The hydrometer isn't an alcohol meter. It measure the amount of sugars in a solution. Since the sugars started at 1.042, and finished at 1.012 (a typical finishing gravity for beer), that's good.

If you really want to figure the alcohol % by volume, the formula is:

(OG-FG) x 131 = ABV

So,
(1.042- 1.012) x 131= 3.93%

Fermentation doesn't take long- maybe a few days. Most lagers are fermented cold, so it might take a bit longer if that's the case. Most of my lagers are done in about 10 days, most of my ales are finished in about 3-5 days. That doesn't mean I bottle then- even when it's done fermenting, the yeast are working to "clean up" the by products of fermentation.

What I'm trying to say in my long winded reply is the beer is finished! Bottle it!

+1. Your beer has definitely attenuated to where it should be...

ReverseApacheMaster 07-16-2010 11:55 PM

That "krud" on top was from fermentation...

hookturn 07-17-2010 01:00 AM

thanks you guys, I forgot that math has to be done. It's my second batch of beer. I started this beer at 50 degrees as it says, but the darn weather snuck up on me and it got up to 70 for about 3 days. It's nice a clear, and has a great taste so I'm happy with that. I sure appreciate all the info you've given me.

Yooper 07-17-2010 01:01 AM

Quote:

Originally Posted by hookturn (Post 2165414)
thanks you guys, I forgot that math has to be done. It's my second batch of beer. I started this beer at 50 degrees as it says, but the darn weather snuck up on me and it got up to 70 for about 3 days. It's nice a clear, and has a great taste so I'm happy with that. I sure appreciate all the info you've given me.

No problem! Are you planning on lagering this beer? It's tough to do without a fermentation fridge, but it can really "smooth out" a lager.

Edit- and not all of us are "guys", but I imagine "people of both sexes who brew" doesn't really sound right.


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