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General Category => Yeast and Fermentation => Topic started by: mrbounds on March 10, 2010, 05:25:14 PM

Title: Need help with possible fermentation problem
Post by: mrbounds on March 10, 2010, 05:25:14 PM
Hi everyone,

I am in need of some advice on a possible problem I have with a brew on the go at the minute. I know I have probably made some pretty stupid errors here but I am learning as I go along....

The  plan was to make a bourbon oak barrelish strong ale. The brews inital gravity was 1.068 and I used the Bedford British Ale Yeast form White labs and the starter was 2 liters and was then repitched in another 2 liters about 24 hours prior to brewing. The fermentation took off very quickly and was very aggressive (blow off hose was required) and I left it in the primary for about 2 weeks. After 2 weeks there was no sign of activity in the airlock so I racked to the secondary. The gravity at this point was 1.033 so no where near what I was hoping for, anyway I went ahead and inserted my bourbon soaked oak chips and occasionally tasted and took gravity readings. Last Sunday I tested again ( 9 weeks in the secondary) and the brew tastes really good but the gravity is still 1.030ish so my questions are:
1: Will I have any issues as far as bottle explosions/over carbonation if I bottle now?
2: Could I repitch yeast into the secondary and attempt to achieve a lower gravity? If so could I repitch some of the original yeast cake which I have kept in the fridge?

Thanks in advance for your kind advice.
Title: Re: Need help with possible fermentation problem
Post by: hamiltont on March 10, 2010, 05:55:12 PM
1.068 - 1.030 =~ 55% Attenuation.  That's not real good. White Labs suggests 72-80%. You could try warming it up a little but I don't think that will help.  Repitching isn't going to help either.  I'd bottle it at this point.  For future reference: Leave it in the primary longer. At least 3 weeks maybe longer depending on the hydrometer readings. Cheers!!!
Title: Re: Need help with possible fermentation problem
Post by: denny on March 10, 2010, 06:15:37 PM
Tell us about your recipe and technique so we can guess if it's stuck or done.
Title: Re: Need help with possible fermentation problem
Post by: euge on March 10, 2010, 06:52:15 PM
Remember-

Check gravity first before transferring or racking! Can't go by time or airlock activity as an indicator that its done.

Was it AG or Extract?
Title: Re: Need help with possible fermentation problem
Post by: mrbounds on March 10, 2010, 07:17:21 PM
It was extract, I will get the complete recipe once I get home, I don't remember off the top of my head. Yeah I will leave it longer next time....you live and learn.
Title: Re: Need help with possible fermentation problem
Post by: euge on March 10, 2010, 07:28:09 PM
Umm... never done it but I think you need to do a starter before re-pitching yeast. IIRC pitching yeast into already fermented brew it needs to be actively fermenting.

How about ferm temps? Did it get a little low for a while?
Title: Re: Need help with possible fermentation problem
Post by: mrbounds on March 10, 2010, 07:33:24 PM
Everytime I checked the gravity I checked the temp and it was always around 64F.
Title: Re: Need help with possible fermentation problem
Post by: ndcube on March 10, 2010, 07:40:09 PM
Everytime I checked the gravity I checked the temp and it was always around 64F.

Did you check it during active fermentation?  It may have been higher than that.
Title: Re: Need help with possible fermentation problem
Post by: mrbounds on March 10, 2010, 07:45:59 PM
I first checked it when I thought primary fermentation had finished ( no airlock activity etc) and then I continued to check the temp and gravity whenever I tasted it in the secondary (every couple of weeks).
Title: Re: Need help with possible fermentation problem
Post by: euge on March 10, 2010, 07:46:27 PM
Welcome to the obsession my friend :-\

I've had various strains consistently stall out and then after a month or a temp change suddenly finish. I tend to avoid these types of yeast and use ones that behave and finish more reliably.
Title: Re: Need help with possible fermentation problem
Post by: mrbounds on March 11, 2010, 12:17:11 AM
Ok... the recipe/technique was as follows:

Heat 3 liters water to 140F add grains : 1lb choc malt, 8oz crystal 60, 4oz caramunich III. Steep 30 minutes. Rinse grain bag with 2 liters water and raise to boil. Remove form heat and add 3lbs dk DME, 6lbs Ex Lt DME, 22 fl oz lyles golden syrup and 4 oz malto dextrin, 8 oz belgian brown soft candy sugar. Disslove and return to boil add bittering hops boil 45 min, add flavoring hops and irish moss boil 10 min add aroma hops boil 5 min. cool to 160F add to cold water in fermentor up to 5 .5 gallons and pitch yeast ( yeast was started as in my original post).

Thanks again for any advice.
                                           
Title: Re: Need help with possible fermentation problem
Post by: denny on March 11, 2010, 05:06:07 PM
Well, the grains and extract do add some unfermentables, but you've also got the syrup and sugar in there which should help.  I don't see any obvious red flags.  You could repitch, especially since you have some yeast slurry.  Generally, if you repitch to restart a stuck fermentation, the advice is to use about a qt. of slurry.
Title: Re: Need help with possible fermentation problem
Post by: mrbounds on March 11, 2010, 05:14:45 PM
Thanks Denny!

Would you advise making a starter with the slurry or can I just repitch a quart of the slurry as is?

Thanks again.
Title: Re: Need help with possible fermentation problem
Post by: denny on March 11, 2010, 05:29:23 PM
I think you'd have the best luck by pitching an actively fermenting starter.  Generally, I like to have my starters finish and decant them, but this is a special circumstance.
Title: Re: Need help with possible fermentation problem
Post by: mrbounds on March 11, 2010, 05:30:37 PM
I will make a  starter and give it a go. I will let you know what happens....if anything.
Title: Re: Need help with possible fermentation problem
Post by: BrewArk on March 11, 2010, 06:00:05 PM
I think you'd have the best luck by pitching an actively fermenting starter.  Generally, I like to have my starters finish and decant them, but this is a special circumstance.

+1

After being in the fridge, the yeast are slowed down.  You want them closer to room temperature in a starter on the upswing not on the downswing.
Title: Re: Need help with possible fermentation problem
Post by: mrbounds on March 29, 2010, 11:18:31 AM
Hi Everyone,

So I repitched the yeast slurry after making a starter and it has been in there a little over a week. There has been very little sign of any activity and a gravity reading yesterday was exactly the same as my previous reading so I am assuming this beer is done and will bottle next weekend. After looking back at my recipe I am wondering if my inital gravity reading was a fluke as there was an awful lot of extract (9lbs), invert sugar (22 fl oz golden syrup) and also 8oz of belgian candi sugar in this brew yet my reading was only 1.068. Does this sound suspect to anyone else? maybe if I hadnt been having a few homebrews whilst brewing I would have taken a second reading  :)

Thanks again for any thoughts.
Title: Re: Need help with possible fermentation problem
Post by: tygo on March 29, 2010, 02:05:40 PM
Yeah, based on your recipe I'd guess you should have been more up in the 1.090 range.
Title: Re: Need help with possible fermentation problem
Post by: a10t2 on March 29, 2010, 10:21:54 PM
Your OG *was* about 1.090, period. The low reading is just due to incomplete mixing with the top-off water.

So you're at about 67% attenuation, which with the dark extract, dark crystal, and maltodextrin, is normal.