Can't Restart Fermention

[bobsaget]

Hi all, this is my first post after being a long time lurker. Hope you can help me out, I will try and keep this short.

I am on to my 4th AG batch and am brewing a porter, I was worried the temp was getting too cold in the laundry so put the fermenter in the kitchen and I killed the fermentation because of the temp shock. So... I tried restarting it by throwing in a new packet of yeast (US-05)- didn't work. Tried using some old yeast slurry I saved from a previous batch (Nottingham Ale yeast) - didn't work. Did some reading up and realized I would have to make a starter. I made one using the 'standard' typical method often talked about - 80g DME to 800 ml water using US-05. All went well, yeast starter bubbled away for 24h, and I put it in the brew with a gentle stir. The brew then bubbled away happily for 15-16 hours and I thought I was home free but then it stopped and I took a gravity reading and its still stuck! There is currently no airlock activity, no foam on top of the brew and the gravity is still stuck at 1030! I really don't want to have to turf this brew any ideas on how to get it going again? Cheers

 

[razz]

Hey bobsaget, welcome to the forums. What temp did you mash at and for how long? You also need to include your starting gravity please? What day do you think the yeast died and when was the last gravity reading taken?

 

[Ducatiboy stu]

Does it taste any good..

If you used a lot of crystal and dark malts, those sugars wont ferment.

bottle it with half the sugar and see what happens

 

[bobsaget]

Hi Razz,
I mashed to high , I overestimated (or underestimated?) how much the grain would soak up the temperature of mash water and it was 69C for 90 minutes. I then sparged at 72C for 10 min. I couldn't explain it, but I knew at the time it wasn't ideal...? The yeast died on Saturday or maybe Sunday - it was going really well until then, nice and foamy on top. The OG was 1048. I put in the yeast starter last night at about 11pm. Noticed it bubbling today at 1 pm, and it was stopped at 4pm. Thats when I took a gravity reading and it was still at 1030 which is what it was at on Sunday.

 

[ChrisECarpenter]

The method I use for starting really stuck (wine) ferments is;

make up your starter with some fermentable sugars as per your rescue starter.

Make up another volume of starting sugars with DME, and after 4 hours from the first starter addition, add the 2nd.
Once you have a really vigourous ferment going with your starter, (which will be eg 1600ml), add 1/2 its volume from your stuck ferment (800ml).
Give it 6 hours, take a gravity reading - hopefully it will have dropped, and you should now have 2.4L of dry beer.
Add 2.4L of stuck beer to this, give it 6 hours and check the gravity - you should now have 4.8L of dry beer.
Add 4.8L of stuck beer to this, 6 hours and gravity check; hopefully now you have 9.6L of dry beer.
your next addition or 2 should consume the last of the stuck beer volume.
This doubling method is very effective at drying out a stuck ferment.
good luck!
Chris

 

[bobsaget]

Make up another volume of starting sugars with DME, and after 4 hours from the first starter addition, add the 2nd.
Once you have a really vigorous ferment going with your starter, (which will be eg 1600ml), add 1/2 its volume from your stuck ferment (800ml).
Give it 6 hours, take a gravity reading - hopefully it will have dropped, and you should now have 2.4L of dry beer.
Add 2.4L of stuck beer to this, give it 6 hours and check the gravity - you should now have 4.8L of dry beer.
Add 4.8L of stuck beer to this, 6 hours and gravity check; hopefully now you have 9.6L of dry beer.
your next addition or 2 should consume the last of the stuck beer volume.
This doubling method is very effective at drying out a stuck ferment.
good luck!
Chris

Thanks that sounds like a good idea. I guess the starter just isn't going to take to the whole batch of beer (23 litres) in one go. And yes being a porter it has lots of crystal, black and chocolate malt in it which is perhaps part of the reason why its having trouble.
Although I wonder if 6 hour intervals would be enough to ferment it out, but I guess I will just take a gravity reading and adjust accordingly.
Bob

Oh and just realised I spelt fermentation, fermention in the title, embarrassing :huh:

 

[bobsaget]

I tried your recommendation Chris, but it didn't work. The gravity didn't change at all.
I'm thinking now that adding any more yeast after the piles I have already added wont get it to ferment. I just stirred it all up to suspend the yeast that is in it, and oxygenate it to hopefully get it going again - but it hasn't. I know that is not ideal to do that but I just can't think of anything else to do. I will leave it another week and just bottle it and I suppose have some very sweet porter to ever so slowly drink.
Bob

 

[ChrisECarpenter]

have you changed the yeast you're using? Any off smells in the beer? All I can think of is that something is toxic to yeast in your wort - which could be something like a native yeast (which clearly can't ferment some sugars and has left the SG high).
Some native yeasts are killer strains and will kill off cultured yeast strains.

Sorry to hear the doubling didnt work.
Chris

 

[bobsaget]

No there is no off smell coming from the wort, in fact it smells better than any brew I have done before which is why I was even less keen than other beers I have brewed to ditch it. As big Kev says, I'm (was) excited!
As for the yeast yes I have changed it.... I was aware that it was not ideal to try and restart fermentation with a different yeast but unfortunately I live miles away from a brew shop. I started fermenting with Safale US-04 originally and have tried to get it going using Safale US-05 because its all I have - and perhaps this is the reason why it all isn't working. I am probably wrong but I thought those two similarly named yeast might also be similar strains of yeast and therefore it should work?? Don't know about that I though I'm only guessing.
The advice about doubling was good, thanks, I was sure it was going to work, doh! I reckon this stuff in going to sit in the shed for a while.
As for something being toxic in the wort I'm not sure, but if you think its worth putting in some US-04 I will order some and try that.
Bob

 

[felten]

I skimmed through the other replies but I didn't see it mentioned, are you using a hydrometer or a refractometer?

Sorry if I missed it.

 

[bobsaget]

I use a hydrometer. I don't have a 'test tube thingy' for it so I put the hydrometer in the top of the fermenter, which should be fairly accurate.

 

[DUANNE]

I use a hydrometer. I don't have a 'test tube thingy' for it so I put the hydrometer in the top of the fermenter, which should be fairly accurate.

if you keep doing that you shouldnt have attenuation problems for long, something wild will end up getting in the beer without a doubt. it is well worth the few dollors for a test tube an added advantage besides being more sanitary is the sample of beer you get to do qc on after testing.

 

[felten]

Do you spin it to knock the bubbles off before each reading?

 

[bobsaget]

if you keep doing that you shouldnt have attenuation problems for long, something wild will end up getting in the beer without a doubt. it is well worth the few dollors for a test tube an added advantage besides being more sanitary is the sample of beer you get to do qc on after testing.

I haven't had any problems with my current method although I don't want an infected batch. What exactly are they called I have been meaning to get one.

Yes I spin the hydrometer to remove bubbles. I'm wondering if pitching more of the same yeast I originally used to ferment the beer would be of any benefit?
Bob