Stuck Stout Ferment

[Budron]

Hi guys,

put on a stout 9 days ago, Recipe:

1x Tin of coopers irish stout
1x 1kg mix from my LHBS (malt, dextrose, corn syrup and some lactose.)
1x Kit yeast

Got an OG of 1040.
I was expecting a FG of about 1008-1010.
It's been sitting on 1020 for the last 5 days and not moving at all.
Mostly temps have been around 18-19c, but possibly dropped to 16c one night.
How can i get this going again? Do you recommend pitching more yeast? What would the kit yeast have been?

Thanks guys, your advice is appreciated.

 

[marlow_coates]

Usual responses to a stuck ferment are as follows,

1. Give the fermenter a gentle shake without splashing it, to rouse yeast into suspension.
2. Rack to secondary vessel for same reason as above. Avoid splashing.
3. Raise the temps with a heating belt (or whatever you have handy) which should increase yeast activity.
4. Add yeast nutrient. You can buy this direct, or boil some old kit yeast to kill it, add to fermenter, yeast in fermenter will feed on it and hopefully start eating the other stuff as well.
5. Be patient

Try any or all of these to get it started again.

Of course it is possible it has finished, if the 1kg of stuff from LHBS was mostly unfermentables?? Do you know what percent of the 1kg package was made up of what? I can't help calculate expected FG, but others may have better knowledge.

Best of luck

Marlow

 

[bum]

Raise the temp a bit if you can and give the fermenter a swirl to get some more yeast back into solution. Just a gentle one, you don't want to be doing any splashing. There should be enough life in your yeast to be able to re-use it for many more brews should you wish so I doubt re-pitching will be necessary.

 

[buttersd70]

As marlow said.

As far as the fermentables are concerned...corn syrup (maltodextrin) is unfermentable, as is lactose....without knowing the ratios that were in the mix, I can't say what the expected sg would be, but I seriously doubt it would be able to make it down to 1010.

 

[Budron]

I stuck the heater on it 2 nights ago and got the temp upto 26c. it's dropped to 21 since then. Everytime I go to take a gravity sample I have to move the fermenter, so it gets a bit of a shake-up then. I remember the package didnt have quantities, only the ingredients. I am wondering now if maybe it has fermented out. But with a OG of 1040 and a FG of 1020, wouldn't that make it only like 2.7%? Maybe I should call the guy at the LHBS.

 

[buttersd70]

Maybe I should call the guy at the LHBS.

Couldn't hurt. He probably won't give you ratios (they tend to jealously guard them like it was a state secret), but he should be able to advise of an estimated fg.

edit....hypothetically, though, if the fermentables were all 250g each, I would expect around a 1016 finish.

 

[manticle]

I'm with butters. I've done a few extract and partial stouts using generic LHBS stout mixes + extra lactose and the unfermentables will prevent an FG of 1010ish. Malt is only partially fermentable, lactose is unfermentable, some stout mixes contain liquorice which I don't believe is fermentable, maltodextrin is unfermentable (or partially fermentable at best - haven't used it for some time but I believe it adds body but no flavour or alcohol).

Try all the usual tricks (swirl, temp raise, kissing the fermenter, an altar to bacchus etc etc) but don't expect 1010

 

[Budron]

Thanks for the responses guys. Got the heat on it tonight to get it to about 26c again, but if tomorrow night it's still at 1020, i might just call it and bottle. Hopefully no exploding ones!

 

[manticle]

Raising temp is good to about 22. 26 might be a bit high.

 

[Budron]

noted, cheers

 

[rackemup]

I leave my stout in the primary for 21 days and i got it to a fg of 1013, so leave it in for longer and stir it a bit every now and then and you will most likely get it to drop further. my opinion is that the yeast do most of their work in the first week but they continue working for a long time after initial fernentation has died away and the gravity will continue slowly falling. also with this tech you end up with a fairly solid yeastcake and very clear beer, (i brew at lower temps).

 

[Bribie G]

<Butters is advised that the following may contain scenes which he may find upsetting>


Welcome to the stuck stout club, my toucan Coopers plus a kilo of dex plus a kilo of LDME got stuck at 1030 after a week in primary. I tasted the hydro sample and it obviously had heaps of sugars left so I tipped in a kettle of boiling water (it was about 23 litres and I normally brew to 25 but had left headspace for volcano head, which hadn't happened fortunately) then I gave it a good stir around with the slotted spoon I use for rousing. That got a bit of oxygen into it and raised it to 21 and it popped off again nicely. It had just been having a granny nap. Nottingham yeast as well, that is usually quite ferocious.
I'll check mine again at the weekend.

 

[the_yobbo]

2. Rack to secondary vessel for same reason as above. Avoid splashing.

Beginner question: Why avoid the splashing? I've been giving my brews that have stagnated a fairly rigourous swirl to try and get them started again. There'd be no dreaded oxygen left in the head space to worry about. The airlock usually gets a bit frothy due to a bit of wort being blown out, but I don't see the harm in that.

 

[marlow_coates]

Do a search for 'Oxidation'. Plenty of info on here.

It is what occurs when oxygen is mixed with the fermented beer, and should be avoided to avoid off tastes.
I have been told it is because oxygen and alcohol makes vinegar. This could be rubbish, but something I always try to avoid. You know the taste of beer that has been sitting too long?

When in the primary there is plenty of CO2 above, but on opening the lid (or lifting the glad wrap) and stirring, it can be said (fairly) that you will mix this up with oxygen, and stir it into the beer, regardless of how careful you are. (Even if it's just a small amount, it can still have an ill effect on the outcome of your beer)

Hope this helps

Marlow