Stuck - intervention required?

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leeh555
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Stuck - intervention required?

Post by leeh555 » Sat Nov 03, 2018 12:25 pm

Sorry guys, another stuck(?) fermentation question from a relatively novice brewer.

I'm brewing an AG Porter and my readings seem to be stuck at 1.018.

I undershot my target OG (1.053) a fair bit at 1.047. Not sure why but carried on. Mashed for 90 mins at 66C.

I rehydrated Danstar ESB yeast and pitched at 19C. It was very vigorous for first 24 hours or so (in to airlock) then slowed down and appeared to have stopped after 48-72 hours. I gradually increased temperature to 22C to encourage more activity. Readings on day 5 and 6 were 1.018 so gave it a stir - no change. The colour and taste are good so I am optimistic that I can still get a nice beer.

I am happy to leave it another week or two but want to ensure that if intervention is required, does it need to be done now or can it be done later. If I need to intervene, should I add yeast nutrient, more yeast (I have US05, US04 & Nottingham available), anything else? If I leave it, should I keep temperature at 22C?

Thanks

MTW
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Re: Stuck - intervention required?

Post by MTW » Sat Nov 03, 2018 1:55 pm

It doesn't sound done, and it sounds like you've done the right things so far, assuming the temp hasn't been allowed to drop at any point. I haven't used that yeast.

Porters can be a bit of a kitchen sink job in terms of grain bills. What was yours?

Hydrometer checked in water?

Otherwise, another stir and if it doesn't move over the next couple of days, it's either done or stuck! I will defer to someone who's used the yeast as to which.
Busy in the Summer House Brewery

leeh555
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Re: Stuck - intervention required?

Post by leeh555 » Sat Nov 03, 2018 4:23 pm

Thanks for the reply. My recipe was for Fullers London Porter from Graham Wheeler's book. The grain bill (for 19L) was:

3490g Pale Malt (Maris Otter)
550g Brown Malt
455g Crystal Malt (200)
92g Chocolate Malt

The colour of my samples is a lovely deep brown and the taste is a pleasant chocolate/toffee taste albeit a bit sweet at the moment.

The Hydrometer is reading 1.000 in water. Temperature has been steady in a fermentation chamber.

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gr_baker
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Re: Stuck - intervention required?

Post by gr_baker » Sat Nov 03, 2018 5:55 pm

I've not used it myself but there are threads on other forums that indicate that 60% attenuation may be what you'd expect from that yeast.

I'd rouse it and give it a few more days and if still stuck chuck in the Nottingham which should get you 75-80% attenuation. Or if you'd be happy with a bit less then use the S04.

Robwalkeragain
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Re: Stuck - intervention required?

Post by Robwalkeragain » Sat Nov 03, 2018 6:21 pm

It doesn't utilize maltotriose does it? Or is that Windsor? So would result in 65% attenuation or so for sure. You need to mash beers with these yeasts super low if you want it to fully attenuate.
US-05 and Nottingham are both solid attenuators and strong starters so either will work well if you want to get down to around 1.008

leeh555
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Re: Stuck - intervention required?

Post by leeh555 » Sun Nov 04, 2018 1:57 pm

Thanks for responses guys. Following the comments I did a bit more searching on Google (perhaps I should have done this in the first place!!) and found the following thread that supports the conclusions gr_baker & Robwalkeragain.

https://discussions.probrewer.com/showt ... -ESB-Yeast

I will rehydrate some more yeast and try to get it down a bit more. Thanks again.

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