Halted fermentation on my monster 1.102 beer

[camers4]

Jan 17th I brewed up an Oat Milk stout that came out to a FG of 1.102.

I made a starter of approx 500 bil cells using WYEAST 1084 which according to Beersmith is lots.

I air-rated the wort for several minutes using the rocking method since I don't have Oxygen. Fermentation started within 18 hours and a blow-off was needed 2 days into it. A refractometer check over a 2 day period shows that it has leveled off at 1.062.

Should I re-pitch? I have 2 packs of Wyeast 1084 that have a November 13 date on them. I also have 6 packs of Nottingham Ale Yeast I could use but I'm not sure if I should mix yeast or not.

What do you suggest?

 

[Sippin37]

First off, refractometers are not accurate for any liquids with alcohol in it. I believe there are conversion calculators out there but not sure how accurate they are, never tried myself. You'll want to use a hydrometer to check the SG once fermentation has begun. Also, you mean your OG (Original Gravity) was 1.102.

I would check with a hydrometer and then check again a few days later to make sure it is still the same. Remember that if you used lactose in there the Final Gravity will not get as low as you are used to, those sugars will not ferment out. Let us know how it turns out for you!

 

[jtp137]

Jan 17th I brewed up an Oat Milk stout that came out to a FG of 1.102.

I made a starter of approx 500 bil cells using WYEAST 1084 which according to Beersmith is lots.

I air-rated the wort for several minutes using the rocking method since I don't have Oxygen. Fermentation started within 18 hours and a blow-off was needed 2 days into it. A refractometer check over a 2 day period shows that it has leveled off at 1.062.

Should I re-pitch? I have 2 packs of Wyeast 1084 that have a November 13 date on them. I also have 6 packs of Nottingham Ale Yeast I could use but I'm not sure if I should mix yeast or not.

What do you suggest?

Got this from another post about stalled belgian fermentation from one of the guys over at CSI. It was given to him by Jamil Zainasheff

Stuck fermentation



Create a new WLP530 stir-plate 3000ml starter. The large starter has be able to quickly ferment under adverse conditions so it has to be large. Oxygenate the starter before seeding with 1 vial WLP530, oxygenate it again at 8 hrs, and after high krausen has subsided oxygenate it a third time. Crash the starter to flocc. Take out of chill and pour off almost all of the starter beer and let the temp normalize to your primary temp. Pitch and stir in *very* gently. In 1-2 days a slow fermentation will resume. Monitor until you reach FG 1.012. Probably another week to 10 days. It worked

 

[peterj]

I agree with Sippin, use a hydrometer. I plugged your numbers into this calculator: http://www.northernbrewer.com/refractometer-calculator/. Came out to 1.036. That could be about all you'll get depending on your recipe. Sounds like a tasty Imperial dessert beer! Enjoy!

 

[camers4]

Thanks for the replies so far.

I did use a hydrometer too and the results were both about 1.065. I just didn't mention it because I thought refractometers were more accurate.


And yes the starting gravity was 1.102, thanks for noticing my error.

This is the recipe. Just switched to WYEAST since my supplier didn't have white labs.
http://beersmithrecipes.com/viewrecipe/346168/oat-monster-milk-chocolate-stout

 

[peterj]

Thanks for the replies so far.

I did use a hydrometer too and the results were both about 1.065. I just didn't mention it because I thought refractometers were more accurate.


And yes the starting gravity was 1.102, thanks for noticing my error.

This is the recipe. Just switched to WYEAST since my supplier didn't have white labs.
http://beersmithrecipes.com/viewrecipe/346168/oat-monster-milk-chocolate-stout

Wait, so you already converted the refractometer measurment and it came out to 1.062? Or are you saying the hydrometer and refractometer both read about the same number? If that's the case, then something isn't right.

 

[blizzard]

What temp are your fermenting at?

 

[camers4]

Correct, the conversion is from about 19.5 brix. I use the converter below. Using this is comes out to 1.066 which is basically the same as the hydrometer reading I took to double check. starting wort brix reading before fermentation was about 24.

http://www.musther.net/vinocalc.html#monitorferment

Fermenting at 18 deg C.

Should I try raising the temp a little to kick start it?

 

[blizzard]

I would raise it a couple of degrees, give the carboy a few gentle swirls to rouse the yeast, and wait it out a few more days to see if it is dropping. If not, I would pitch a nice active starter to get things going again.

 

[Calder]

Fermenting at 18 deg C.

Should I try raising the temp a little to kick start it?

Thats right at the bottom end for that yeast. If the beer is sitting on a cold floor, or the temp drops at night, it could be colder.

A possibility is the yeast started ok, and self generated heat for a while, then it started to slow down, and lost heat. Got too cold and quit working.

If that us the case, heating it up should get it going. It might need a gentle stir too.

 

[camers4]

I think your spot on. I used a laser thermometer and it was sitting at 15 deg C. I moved it to a warmer spot and gave it a gentle stir. Hopefully this kicks it off again.