Mashed too high, what are my options to unstick this fermentation (if any)?

[tboog86]

I've been messing around with mashing overnight at full volume (so I guess you could call it BIAB eventhough I'm still using my converted Igloo mash tun) to split up my brew day. It has worked pretty well but I recently brewed a baltic porter (recipe below) and I missed my target mash temp of 154F and mashed at 158F overnight, dropping to 155F over about 7 hours. It has been fermenting for about 9 days and has been stuck at 1.028 for about 3-4 days. I used a quick lager fermentation schedule, fermenting with 4 rehydrated packets of Saflager 34/70 at 55F for 5 days and then ramped the temperature up to 68 for 2 days and when I didn't see any additional activity on my TILT I ramped again to 75F for the last two days. A hydrometer reading last night confirms it is at 128F so I added some yeast energizer last night.

If that doesn't work is my mash temp of 158F so high that I won't get down past 1.028 or is there a chance I could shave a few more points off by adding another packet of 34/70? If I do, will I need to drop the temperature down to prevent off flavors from another growth phase?

If 1.028 seems like the best I'm going to get with that yeast, is my best option to add a diastaticus strain? In that case I worry about it getting to dry and spoiling my low ester lager fermentation with additional esters (or do I not need to worry about that since the bulk of the fermenation is done).

RECIPE:
Title: Baltic Porter

Boil Time: 60 min
Batch Size: 5.25 gallons (fermentor volume)
Boil Size: 6.5 gallons
No Chill: 20 minute extended hop boil time

STATS:
Original Gravity: 1.072
IBU 31.7
SRM: 31.24

FERMENTABLES:
8 lb - Dark Munich (58.2%)
4 lb - Floor-Malted Bohemian Pilsner (29.1%)
0.5 lb - CaraRye (3.6%)
0.5 lb - Carafa II (3.6%)
0.5 lb - Special B (3.6%)
0.25 lb - Pale Chocolate (1.8%)

HOPS:
2 oz - Hallertau Mittelfruh, Type: Pellet, AA: 3.2, Use: Boil for 40 min, IBU: 21.66
1.75 oz - Saaz, Type: Pellet, AA: 2.8, Use: Boil for 0 min, IBU: 10.04

MASH GUIDELINES:
1) Infusion, Temp: 158 F, Time: 7 hr, Amount: 8.53 gal


YEAST:
Fermentis / Safale - Saflager - German Lager Yeast W-34/70 (4 packets/44g)

 

[Gus_13]

You may could get fermentation started again by adding some amyloglucosidase enzyme to help restart fermentation. That's the enzyme people use to dry out Brut IPA. It may ferment further than you want though.

Here's a few articles on it.

https://fifthseasongardening.com/how-to-deal-with-a-stuck-fermentation

http://brulosophy.com/2018/11/26/ad...-to-the-beer-in-brut-ipa-exbeeriment-results/

 

[TandemTails]

what kind of magic are you doing that you only drop 3'F over the course of an overnight mash?

My suggestion would have been heating the beer but you've already tried that. Maybe wait another couple of days and see if the energizer did anything. you could also try gently swirling the carboy to rouse the yeast back into suspension and see if that starts it up again.

 

[tboog86]

In the two times I’ve tried it I’ve found the key to keeping a consistent temperature is just doing a full volume mash with no sparge. That much water in the cooler doesn’t seem to drop much.

 

[Kenmoron]

There are actually 2 kinds of enzymes that can be added to break it down further. As mentioned above, amyloglucosidase is what people use to get really dry beer (can break down starch chains more efficiently than amylase). However, if you are looking to just bring it down a bit more without getting too dry you could try adding just amylase enzyme. Most products out there are just alpha amylase (no beta) so they may break it down a bit more but not quite as efficiently as if you had alpha and beta. If you could find a product with both alpha and beta that might be your best bet.

 

[tboog86]

Right on, that's exactly what I ended up buying after reading those links and will add tonight. I'm definitely not looking to give this thing the Brut IPA treatment with amyloglucosidase but if I can get this thing down to even 1.02 I'd be happy. If not, it tastes decent as it is but its a little on the sweet side.

Right now my plan is to add the amylase enzyme and if it doesn't result in any activity, add one more packet of yeast in case it all went dormant and if nothing works then just start cold conditioning and move on. My only concern about adding the yeast is the beer is already at [fairly high] diacetyl rest temps and adding some fresh yeast might throw some unwanted esters during a new growth phase.

 

[tboog86]

Quick update. I started getting activity again from my blow off 1 day after adding the amylase enzyme but didn't see any gravity drop on my Tilt so I got impatient added another packet of re-hydrated dry yeast the next day and started seeing a 1 point drop every other day or so. After 12 days it has dropped from 1.028 to 1.021 (unofficial reading from Tilt). My blow off has gone from bubbling every 3-4 seconds to every 9 seconds so it seems to be slowing but still seeing some consistent activity, although that may just be degassing.