Bit High FG - Should I rack or wait for it to come down?

What went wrong? Was this supposed to happen? Should I throw it out? What do I do now?

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Bit High FG - Should I rack or wait for it to come down?

Postby Michael Kazeuma » Fri Dec 04, 2009 9:56 am

Working on a Forbidden Fruit Grand Cru clone and needed some help.

Data:

11.23 Pitched at SG of 1.110 at 20 degrees
11.29 Gravity is at 1.055 at 20 degrees which is about 7 % abv

Fermentation with the Wyeast Activator Forbidden Fruit yeast seemed to be a bit tired after a week so...

11.29 Pitched second dry - Safale S-04 11.5 grams into 16 liters

Perhaps abv is too high or oxygen is gone or too many remaining sugars, but the S-04 yeast just didn't go anywhere. Kind of sputtered along and moved the FG or Present Gravity down to around 1.050.

The original recipe was for SG at 1.084 and FG was targeted at 1.018. That is a drop in 66 points. However, presently I have only dropped from 1.110 to 1.050 which is a total decrease of 60.

Should I just consider this beer ready with the drop in Gravity of 60 or should I just rack it off and let it lay around for a while. And even if the Gravity is not as low as the original recipe, should I still bottle at the same amount of priming sugar or should that be adjusted to take into consideration that a higher level of sugars still exist in the wort. The tasting on the 29th wasn't bad, but a bit sweet..... Considering doing a dry hop before racking and bottling. Can I get away with racking it off and letting it set for a couple of weeks before bottling? I am planning on going on a trip in a couple days so any advice on what to do before leaving would be great!

Thanks!

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slow fermentation

Postby slothrob » Fri Dec 04, 2009 11:22 am

I don't have specific experience with this yeast, but I think it might be a slow fermentor and need some warmer temperatures to properly finish. Also, a big beer like 1.110 is going to take more time to finish.

I'd warm it up into the 70's, if possible. Then I'd leave it alone for a couple more weeks, except maybe giving it a swirl every once and a while, to see if the gravity drops. Big beers typically take weeks and months to do what small beers do in days and weeks.

The other possibility is that the recipe hasn't been formulated to finish at 1.018. If the beer was originally designed to start at 1.084, then was scaled directly to 1.110, you wouldn't expect it to finish any lower than 1.025. If the 1.018 was a generous estimation of the attenuation, which would depend a lot on the recipe, then the FG will be even higher. I think 1.050 wouldn't make a very drinkable beer, though, so I'd give it some time and hope it goes lower.

What was the recipe?
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Slow Fermentation

Postby Michael Kazeuma » Fri Dec 04, 2009 9:14 pm

Thanks for the reply!

I have the fermentation temp controlled with aquarium heaters so I can crank it up to the 70s quite easily. Can I leave the beer on the trub for another two weeks? I pitched on the 23rd and wouldn't be able to get it off the trub until the 20th? I'll shoot for a FG of 1.025.

Recipe (I'm translating directly from Japanese so please excuse any funky expressions and spelling)

Special malt - 650 g (held at about 68 degrees for 30 minutes)
Malt extract - 3,740 g
Zaas hops (bittering) - 35.5 (30 minutes boil)
Zaas hops (aroma) - 7 g (15 minutes)
Grape glucose - 1,000 g
Irish moss, spices, orange peel

Recipe called for 19 Liters or about 5 gal., however I seemed to have not put in enough water and ended up with 'slightly' higher SG at 1.100, which was supposed to be 1.084.

It would be perfect to just leave this beer percolating for a couple of weeks! i'm in no rush...

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slow fermentation

Postby slothrob » Sat Dec 05, 2009 10:43 am

I don't have a lot of specific experience with Belgian yeasts, but a number of them are famously slow fermenters and often require an elevation in temperature to complete the job. I'm hoping that this is the case with your beer and it just needs some time to finish.

It's possible that the yeast ate through the simple sugar, then stalled on the more complex sugars from the malt. Hopefully, the rise in temperature will get the yeast going again. Because of this phenomenon, my friend who makes a lot of strong Belgian beers usually waits until the primary fermentation is starting to slow down before adding the simple sugar to the fermenter. By then the yeast has eaten a lot of the more complex sugars and the yeast aren't stressed as much as trying to ferment the high gravity from the start.

I doubt the extra time will hurt, and it's worth the risk as it's much better than the alternative of bottling a 1.050 beer.
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Slow Fermentation

Postby Michael Kazeuma » Sat Dec 05, 2009 12:07 pm

Very interesting. I will definitely use the advice and thanks for taking the time to help me out. I'm on a plane tomorrow morning and I was a bit concerned about what to do. Leaving the wort percolating along at a higher temp sounds like a good idea since I certainly don't have time to bottle. I was actually planning on gradually sliding the temp up over two or three weeks, but when it started to sputter i wasn't really sure which way to go! Perhaps in a about 10 years I'll be cranking out some consistently great imperials!

Cheers!
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FG dropped 80 points - Priming Sugar Calculations?

Postby Michael Kazeuma » Sat Dec 19, 2009 12:15 pm

SLothrob and fellow brewers,

Just came back from my trip (got to try an awful lot of craft beers) and as a follow up to our earlier discussion, the second pitch has brought the specific gravity down to 1.030. I also pitched with that second yeast two more liters of water with a shot of dry hops about 14 days ago. Raised the temp slightly to around 22-23 C and held.

There seems to still be some mellow fermentation activity, but I'm thinking that after a month I should get it off the trub and bottle. At the 1.030 would I still need to add priming sugar and if so, is there calculator for that purpose. Obviously I'm way off the original recipe's FG. The move from Initial Gravity of 1.100 to 1.030 is more than the original recipe. Gravity dropped 80 compared to 66 in the original clone recipe for Forbidden Fruit.

Any comments are most welcome!

Thanks,

Michael



P.S: On my trip I thought the Hercules Double IPA from the Great Divide and another hoppy brew from Yakima were quite impressive.
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