high gravity - stalled fermentation?

[Dionustra]

Hello all. I have a high gravity beer - target 1.080 - that's been going for about 6 weeks, but that's been sitting at 1.045 for the past 3 weeks. I even pitched another batch of yeast into it about 2 weeks ago, but it hasn't changed. Could it be because I failed to make a starter? If so, should I do a starter and add yet another (3rd) batch of yeast? Also possibly relevant is that it has been in a cool environment - within the range listed for this yeast, but down at the bottom of the range. Perhaps I should move it to a warmer environment nearer the top of the listed temp range? Thanks in advance for any advice....

 

[BrewStooge]

Also matters what type of yeast, for my high grav it's usually White labs Trappist (wlp500) otherwise you may be throwing good yeast after bad, but a boost in the temp couldn't hurt, also give it a swirl to get it back in suspension might help too.

 

[hoppymonkey]

+1, what yeast are you using? 1.080 is not super big and there are several yeast that should do fine with it, but some may not. Nottingham, WLP001,wlp099, any trappist type will eat that just fine and yes bring the temp up some could definitely help. If you do that, be sure to give the carboy/bucket a few good swirls and bring the yeast back in suspension. ONe other question, How well did you oxygenate it before pitching?

 

[Dionustra]

Thanks for the responses. I used Wyeast's 1388 Belgian strong ale yeast - both pitches. I did aerate well before the first but not before the second, because I was afraid of introducing too much oxygen at this late stage. I did move it to a warmer area and give it a good swirl. Should I aerate at this point? Give it a couple of days before considering a 3rd pitch?

 

[Bierliebhaber]

Don't aerate at this point. With propper use, your yeast shouldn't have any problem with this OG. Raise the temp and give the fermenter a swirl both in the morning and before you go to bed (early evening wouldn't hurt either) for the next 3-4 days. After that, take a reading to see if things are improving.

You should have definitely made a starter for this beer (lesson learned), but if the above does not work you can do a couple other things. 1) Add yeast energizer (you could do this along with swirling, too). 2) Make a well aerated starter; place it in another carboy/bucket and rack onto it.

Some other helpful information that will help us help you is: Is this extract or all grain? What malts/grains did you use? If AG, what was your grain bill and mash temps? What temp did you pitch the yeast at? Did you add yeast nutrient at the end of the boil?

Assuming a 5 gal batch and a single pk of yeast pitched, my guess is that you underpitched and the yeast gave up. You would have needed to pitch 3 packets of yeast to have enough. With a good starter, your yeast would have been jumping and ready to work.

Cheers

 

[dcp27]

even tho this was pretty significantly under-pitched (~1/3), you definitely should have gotten further down than that. how low of temps are you fermenting at? some belgian strains are a bit temp finicky and will floc out if the temp drops.

if the swirling and temp raising doesn't work, id make a highly aerated starter and pitch it at high krausen.

also, just to be sure, that FG is with a hydrometer not refractometer right?

 

[Dionustra]

Thanks for the responses. I’m learning a lot that will help me in the future. To answer the questions, I used extract, with a recipe that included:

14 oz German crystal malt
4 oz Belgian aromatic malt
3 oz Belgian Cara-Munich malt
2 oz Belgian biscuit malt
11 lb. M&F extra light DME
1 lb. M&F wheat DME

I pitched the yeast at 78 degrees, didn’t use yeast nutrient at the end of the boil, and am taking readings with a hydrometer. I’ve moved the beer to a warmer place and am swirling, with a view to following the suggestions about yeast energizer and / or racking on to well aerated yeast starter in a few days if there’s no progress.

Thanks again for the help.

 

[dcp27]

what size batch was this? that recipe puts you way over 1.080 at 5gals, closer to 1.110