Attenuation - Should I add more yeast?

[nickrjsmith]

I did a full mash 2 weeks a go. OG 1050ish. The fermentation has stopped and seems to have stopped for the last 6/7 days.

I used Nottingham ale yeast, which I usually do, but normally I do OG around 1045. The yeast packet says for around 4.5 gals and I normally do around 5 gal.

I normally get a FG of 1010, although this time it's still at 1020 2 weeks later.

QUESTION: It does seem as though fermentation has stopped. Is it worth adding more yeast to finish the brew off? Or will this wreck it?

Thanks

 

[jmhart]

I did a full mash 2 weeks a go. OG 1050ish. The fermentation has stopped and seems to have stopped for the last 6/7 days.

I used Nottingham ale yeast, which I usually do, but normally I do OG around 1045. The yeast packet says for around 4.5 gals and I normally do around 5 gal.

I normally get a FG of 1010, although this time it's still at 1020 2 weeks later.

QUESTION: It does seem as though fermentation has stopped. Is it worth adding more yeast to finish the brew off? Or will this wreck it?

Thanks

Adding and/or repitching yeast won't help. 1020 isn't bad, just a bit sweet. If you want to dry it out, rack in onto a yeast cake from another brew, should drop it down to 1010 in just a couple of days. Fresh yeast won't be able reproduce enough and definitely won't have the sterols necessary to finish out the fermentation.

 

[sigsegv]

I've heard of people adding beano (do a forum search) as an option to restart a stuck fermentation. It's possible that the mash didn't break down the sugars enough so the yeast can't completely process it. I think this is where the beano would help. Yeast nutrient might be another option too. I doubt that repitching more yeast would be harmful but since the original pitch already attenuated down to around 50% it seems like it probably should have been healthy enough to finish out.

 

[jmhart]

I've heard of people adding beano (do a forum search) as an option to restart a stuck fermentation. It's possible that the mash didn't break down the sugars enough so the yeast can't completely process it. I think this is where the beano would help. Yeast nutrient might be another option too. I doubt that repitching more yeast would be harmful but since the original pitch already attenuated down to around 50% it seems like it probably should have been healthy enough to finish out.

If you underpitch or don't oxygenate enough, yeast can absolutely burn out before they finish a beer. Repitching won't fix it.

Aside from racking onto another yeast cake, you could also try racking to secondary. Often the simple act of racking to secondary can stir up the yeast enough to drop it down a bit more.

 

[Frodo]

What was your mash temp? Higher this time than your previous brews?

 

[Yooper]

What was your mash temp? Higher this time than your previous brews?

I also think this is the issue, not the yeast or aeration. A 1.045 beer, using nottingham, should easily finish at 1.010 or so IF the mash temperatures were correct and IF the ingredients were fermentable.

Double check your thermometer, to make sure it's accurate.

Another thing to keep in mind is the recipe- some ingredients are less fermentable (or even non fermentable) than others, so that can contribute to the higher FG.

What was the recipe and mash temp?

 

[Alemaker]

I feel your pain. I brewed a 1.042 beer, used Nottingham, and am stuck at 1.020 12 days later. I mashed at 155, and I think my thermometer is pretty close. I do think it may have gotten a little cold (even though Nottingham is supposed to be fine down to 57), but I've moved it to a warmer place and have not seen a drop in gravity. I stirred up all the yeast with a racking cane tonight. I'm hoping that will get it moving again. 1.015 would be acceptable to me, but 1.020 is a big disappointment for a 1.042 beer.

Not to hijack this and turn it into another one of "those" threads, but... my Nottingham lot number is 1080472V exp. 07 2012...not heard anything bad about this one. It started quickly enough. I had active fermentation in 12 hours.

 

[lumpher]

i have a 1.050 apa fermenting right now, and it stuck at 1.023 for 2 days. i swirled it around a little, and it started popping merrily again. down to 1.012, and ready to keg tomorrow. just pick up the fermenter, gently slosh it back and forth a little, and see if that helps.

 

[Frodo]

i swirled it around a little, and it started popping merrily again. down to 1.012, and ready to keg tomorrow.

I always think those guys that say, "just swirl it a little and see if that helps" are full of **** and just have no clue what to do but want to try to help... I'm re-thinking that now.

 

[nickrjsmith]

Hi,

GOOD NEWS! I gave it a stir last night (very gentle) and this morning the airlock has started to bubble again.

I usually have a pretty constant temp (low around 15/16 degree c) and it ferments fine but I did go away over Christmas and I reckon that the beer got too cold as the heating in the house was off.

Crossing fingers it'll get to 1012 in a couple more days, I have a brand new top tap to rack it into.

Thanks for all advice, I'm glad I didn't pitch any more yeast.

 

[DrawTap88]

Glad you were able to get it going again. I was just about to suggest the swirl method, but to also heat it up a little bit.