Stuck Ferment

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Kai

Fermentation Assistant
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One of my brews has been stuck for a week now despite my best efforts to rouse it. Details at eleven

::checks watch::

close enough..

it's a small batch I brewed a couple weeks ago, 1.5kg pils malt, 500g wheat 500g flaked maize, intended to test out my hone grown chinook. It was meant to be a partial mash but I forgot to buy any extract so made it a tiny AG, hence the high proportion of corn.

It started off at 1.050, but halted at 1.018 a week ago. I spent a couple days rousing the yeast, warmed it up to around 22C, and even pitched a half a sachet of SL-33 in (not rehydrated, though) an attempt to get some action, but no dice. Any suggestions on the best course of action from this point?
 
I had a porter that did the same last week, i gave up after 3 weeks in the secondary and wacked it in a keg. Tastes a little thick but other than that its ok. I had a couple of ideas about my 1019 FG, I think that i was mashing too hot (68-9) i recall, so this could contribute to the higher FG if you did that. Its probably a bit more of a problem in the outcome of your beer (which i assume is a pilsener) , so you wont get that nice dryness. What yeast did you use btw?
 
Oh year, forgot to mention the yeast. I used 1272 American ale II. it was a very old wyeast pack but started up ok.
 
A packet of Nottingham will get the ferment going again. Failing that, pitch a champagne yeast.

Jovial Monk
 
Kai said:
it's a small batch I brewed a couple weeks ago, 1.5kg pils malt, 500g wheat 500g flaked maize, intended to test out my hone grown chinook.
[post="60246"][/post]​

Kai,

With such a high proportion of adjuncts did you do a starch conversion (iodine) test?

Maybe there's a small chance you've got a high proportion of unconverted starch in your beer? Does it look a little hazy?

If nothing is shifting it i'd just go ahead and keg or bottle it. Chances are it's as attenuated as it's going to get.

Warren -
 
What was the mash temperature and how certain are you about your thermometer calibration?
 
Kai,
This time of year many peoples ales stop short. I reckon it is the colder overnight temps. How are you keeoing it at 22?
 
In my bathroom with a heat belt and a towel, Darren. You are right though, I went away for a weekend and we had a cool change which dropped it to 14. That was when I found it stuck.

Lurker, I don't remember my mash temp and unfortunately this was the one batch where I didn't record anything. More importantly, though, I don't remember it being out of the ordinary, and I haven't had any problems with other beers although my thermometer has not been calibrated.

Warren, no I didn't do an iodine test. The beer is still hazy but I assumed there was still yeast in suspension. Perhaps I might have to find some iodine.
 
Oh yeah, and now that my memory is a little more jogged, I do remember reading that it's not a good idea to use pils malt with high adjunct levels as the enzymes sometimes cannot cut it, but I can't vouch for that source as I can't remember it. I do remember hoping that the wheat malt would have enough enzyme to make up the difference.
 
You most probably had a severe lack of a grainbed too Kai.

If there was unconverted starch in the mash this would have inflamed the problem somewhat too. You've probably sparged quite a bit out.

Warren -
 
Have you tried giving the fermenter a gentle swirl or even a very careful stir with sterilised paddle?
 
Jim, yes I tried giving it a gentle shake for a few days.


Warren, no dice on the starch theory. Mr. Betadine antiseptic liquid (plus Ms. cornflour positive control) tell me I don't have any starch in my beer. Back to square one :(

I do wonder what the lady in the chemist thought though, as I bought a packet of razor blades while I was there. Together with the iodine she probably thinks I must be a fairly rotten shaver :)
 
Well, I'm going to have another crack at a repitching, this time with one that's champing at the bit and rearing to go.
 
It appears to be going again, I threw in another starter a few days ago and thought it was not successful, was going to go by some amylo today and chuck that in, but didn't get around to it. Good thing too, since about half an hour ago I noticed it was all krausened up again. Woohoo!
 
Non-woohoo, a week later the krausen is still there, but the gravity has not budged. Gave up today and threw some amylo in.

Houston, we have fermentation.
 
Enzymes are not the answer to a stuck ferment. 23g Nottingham would have got that sucker attenuating no probs

Jovial Monk
 
What would Nottingham have done that SL-33, in both dry and starter, did not?
 
Good to read Kai, that the enzyme got your stuck brew fermenting. Is definitely the path I would have gone down, considering that you tried resuspending, then a fresh yeast starter and suspected too much long chain stuff in the brew.

Let us know what the end result tastes like.
 
I just had to unstick a braggot that had stuck at 1.030. I threw in 3lb of pureed strawberries. That got it rocking. I had to put the blowoff tube back on. It's down to 1.009 now.

Travis
 
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