Escape from Stuck Fermentation Mountain - AE to the Rescue!

[ten80]

Now do I need to add more enzyme or possibly warm up the carboy? 2 tsp should be more than enough enzyme, though it works best when dissolved in warm (~100F) water before adding to beer. warming the carboy and agitating it will increase enzyme activity and contact with beer. However, I think you have a yeast health issue (read below).

Did I pitch the wrong enzyme? Amylase is a "safe" enzyme that will not attenuate your beer beyond the theoretical maximum for the malts you used, though you didn't use any malts with low fermentability (i.e., crystal malts). I'm guessing you have a yeast heath issue. 34/70 is usually a pretty hardy yeast that chugs along to completion.

Do I need to pitch some fresh yeast? This would be my recommendation given that you don't have a HUGE beer with a potential wort fermentability issue. Pitch an active, decanted starter of a neutral-profile yeast such as US-05, WLP099, California Ale, etc and ferment away at 65-70F, gradually ramping up to 75 ish over the course of about 7-10 days. Agitate the beer several times daily to keep the yeast in suspension.

I was hoping to at least get the beer down below 1.020 as I'm only sitting at 65% apparent attenuation. Seems like you should be finishing in the ~1.010-1.012 range with your malt bill

Thanks!

 

[passedpawn]

Long time lurker bumping this thread as I know find myself atop the stuck fermentation mountain!

Brewed the following Rye/Vienna Lager back in early April:

Brew date: April 4/19

Ingredients
Amt Name Type %/IBU
10 lbs 12.0 oz Viking Vienna Malt (4.3 SRM) Grain 86.9 %
12.0 oz Viking Munich Malt Light (8.1 SRM) Grain 6.1 %
12.0 oz Viking Rye Malt (3.6 SRM) Grain 6.1 %
2.0 oz Carafa III (525.0 SRM) Grain 1.0 %
0.88 oz Magnum [11.70 %] - Boil 30.0 min Hop 28 IBUs
300mL Saflager Lager (DCL/Fermentis #W-34/70) (Slurry) Yeast

OG: 1.058
Fermentation temp: 52F

Target Mash temp: 153F (only found out later my thermometer pen was reading 6F below, so my mash temp was more like 159F-160f!!!)

I knew something was up when two weeks later I took a sample and it read 1.028, however all signs of fermentation had stopped! Again at this point I didn't realize I was mashing so high and didn't attribute the poor attenuation to underpitching as I more or less re-pitched an entire fresh yeast cake/slurry into this lager.

So I finally found this thread and found me some Alpha Amylaze Enzyme (https://stillspirits.com/products/alpha-amylase-enzyme-sachet-4g).

May 1st - Added 2tsp Alpha Amylase Enzyme directly to the carboy and saw some activity right away, sitting at room temp ~65F
May 6th - Took a sample, read 1.020....but since then I have taken 2 more samples and it seems to be leveling off at 1.020.

Now do I need to add more enzyme or possibly warm up the carboy? Did I pitch the wrong enzyme? Do I need to pitch some fresh yeast?

I was hoping to at least get the beer down below 1.020 as I'm only sitting at 65% apparent attenuation.

Thanks!

Probably should go lower than 1.020. Adding more yeast can't hurt and might help. I'd do that, monitor gravity, and wait for a week of stability before bottling.

 

[Cameron McKellar]

Probably should go lower than 1.020. Adding more yeast can't hurt and might help. I'd do that, monitor gravity, and wait for a week of stability before bottling.

Yes that's what I was assuming it should go below 1.020. I added some more yeast and will check the gravity next week, thanks for all the help!

 

[Cameron McKellar]

Ok good news folks I added some new yeast and finally was able to get it down to 1.014-1.015 FG.

I kegged er up and it tastes great. Now I run into another issue (this beer seemed to be doomed from the beginning) with head retention. The beer is carbed well but the head retention is next to nothing, the head dissipates completely within a minute or two.

Does anyone have experience with AE killing head retention?

I know it can't be glassware since it happens in all glasses (both those from dishwasher and hand washed) and my lines were recently cleaned.

Like I said I am least happy to get this beer in a drinkable range, but the head retention is something that I'm curious about.

Thanks!

 

[ten80]

.....Does anyone have experience with AE killing head retention?
Thanks!

There is no immediate relationship between AE and head retention. AE specifically targets carbohydrates and head retention is largely due to protein. There may be another factor like fatty acids released from autolized yeast (due to the extended time in primary), grain bill, etc.

 

[passedpawn]

Ok good news folks I added some new yeast and finally was able to get it down to 1.014-1.015 FG.

I kegged er up and it tastes great. Now I run into another issue (this beer seemed to be doomed from the beginning) with head retention. The beer is carbed well but the head retention is next to nothing, the head dissipates completely within a minute or two.

Does anyone have experience with AE killing head retention?

I know it can't be glassware since it happens in all glasses (both those from dishwasher and hand washed) and my lines were recently cleaned.

Like I said I am least happy to get this beer in a drinkable range, but the head retention is something that I'm curious about.

Thanks!

Might give this a listen:

http://www.thebrewingnetwork.com/brew-strong-foam/

 

[tboog86]

How long before people are seeing fermentation start back up? Added 2 tsp 24 hours ago to a Baltic porter that was stuck at 1.028 down from 1.072 and no activity from the blowoff yet or change on my Tilt. I have some more yeast ready to go in case nothing happens but Id like to minimize how much I mess with it since I added yeast energizer 3 days ago too.

 

[Dland]

Another question, somewhat related to this thread; What percentage of high amylase grain, such as distillers malt, would one add to grain bill to achieve affect of adding a given amount of amylase powder?

While this does not address stuck fermentation, it might be a good tool produce drier styles of beer. Or I suppose one could make a wort using some of this to add to a larger stuck batch.

I have learned, from previous inquiries, that distillers malt as a base malt does not produce particularly good beer, so it would be an adjustment tool for mash, much like acid malt, used sparingly in measured quantities.

 

[Vale71]

If the fermentation is really stuck then there is no reason why it should start again. If your beer is really not at FG then there are already fermentable sugars but the yeast has given up on them for one or possibly several reasons. Adding enzymes to the beer will only produce more fermentable sugars but it won't affect the yeast directly (i.e. it won't restart its metabolism).
As a matter of fact, just adding enzymes has the potential of making things even worse, creating a sweeter beer that will be even more susceptible to infection and/or unforseen fermentation restarts (i.e. potential bottle bombs).

 

[passedpawn]

If the fermentation is really stuck then there is no reason why it should start again. If your beer is really not at FG then there are already fermentable sugars but the yeast has given up on them for one or possibly several reasons. Adding enzymes to the beer will only produce more fermentable sugars but it won't affect the yeast directly (i.e. it won't restart its metabolism).
As a matter of fact, just adding enzymes has the potential of making things even worse, creating a sweeter beer that will be even more susceptible to infection and/or unforseen fermentation restarts (i.e. potential bottle bombs).

I think the term "stuck fermentation" sometimes refers to problems caused by high or low mash temperatures, in which starch conversion didn't complete. Those problems will be helped by adding additional enzymes (the original ones will have been denatured by the boil). The assumption is that there are viable yeast left in suspension, which is a good assumption unless it's a high ABV beer.

In the case of non-viable yeast, you're right!. Probably the best thing to do any time a beer fails to get to the expected gravity is to add new yeast AND enzymes. I don't see a downside to doing this.

I'm not a fan of fiddling with the beer once the yeast gets started. Fortunately, in all the batches I've made, I've only had a fermentation stall once, which was the time I created this thread.

 

[kh54s10]

If the fermentation is really stuck then there is no reason why it should start again. If your beer is really not at FG then there are already fermentable sugars but the yeast has given up on them for one or possibly several reasons. Adding enzymes to the beer will only produce more fermentable sugars but it won't affect the yeast directly (i.e. it won't restart its metabolism).
As a matter of fact, just adding enzymes has the potential of making things even worse, creating a sweeter beer that will be even more susceptible to infection and/or unforseen fermentation restarts (i.e. potential bottle bombs).

Not sure about this. I had a stuck or stalled fermentation. It was too high FG at 2 weeks. I warmed it up and swirled. I did not have to add anything. It kept going and ended up at a reasonable FG and was very good.

Why would adding enzymes to a beer make it sweeter. If it actually lowered the gravity it should be drier. And if the alcohol content is raised the possibility of infection should be lowered.

 

[Vale71]

I think the term "stuck fermentation" sometimes refers to problems caused by high or low mash temperatures, in which starch conversion didn't complete.

Add an "improperly" before "refers" and I'm inclined to agree with your statement...

With really absurdly high FG values it must be a "proper" stuck fermentation as high mash temperatures alone cannot explain such low attenuation values. Either that or conversion was grossly incomplete in which case amylases would help greatly but before blindly throwing enzymes in the fermenter I would do a simple iodine test to check for that (yes, you can do it with beer as well and it's actually a standard QA practice in large breweries).

 

[passedpawn]

Add an "improperly" before "refers" and I'm inclined to agree with your statement...

With really absurdly high FG values it must be a "proper" stuck fermentation as high mash temperatures alone cannot explain such low attenuation values. Either that or conversion was grossly incomplete in which case amylases would help greatly but before blindly throwing enzymes in the fermenter I would do a simple iodine test to check for that (yes, you can do it with beer as well and it's actually a standard QA practice in large breweries).

I didn't even think about iodine, and I have it in my kit. Good idea.

 

[passedpawn]

Why would adding enzymes to a beer make it sweeter.

Vale was describing the situation in which the yeast is not viable, and then you convert starches to sugars by adding enzymes.

 

[kh54s10]

Vale was describing the situation in which the yeast is not viable, and then you convert starches to sugars by adding enzymes.

OK. That was, and still, is not clear to me in reading the reply. "yeast has given up", to me does not equal not viable.

 

[alexjames23]

I just made an account here because of this post. Been reading through the thread several times now, and finally bit the bullet. I'm brewing 4.1 gallons of a Golden Milk Stout. Never brewed this (non-BJCP) style before. Closest style to it would be a sweet stout. The recipe for it called for a mash temp of 156, I assume to give the beer a sweeter, fuller taste and mouthfeel. I have a entry-level thermometer, nothing too special, and I think I made a couple mistakes. My strike water was about 5 degrees too hot, and I tried to let the temp come down naturally instead of messing with any water - I did this for probably 5 minutes then eventually poured a bit of cold water in to force the mash temp down to 156. Red flag/learning experience #1. Then throughout the mash, when the temp would drop a couple of degrees, I'd turn on the burner to heat it back up, and neglected it more than I should've to the point that it got up to 159-160 once - Red flag/learning experience #2. Point being I think I denatured some of my enzymes during the mash and ended up with more unfermentable sugars than ideal. Will not be making those rookie mistakes again in the future.

Ended up with 1.081 OG. Pitched a bag of re-hydrated Nottingham. Airlock was bubbling out the top for about 24-36 hours, temp according to my entry-level thermometer stuck into my thermowell indicated temp got up to about 79 (red flag/learning experience #3, just bought a mini fridge to-be-converted-to-ferm chamber today), then day 3 and on there was no airlock activity whatsoever, no churning, small krausen. Took hydrometer reading on day 5 and got 1.040. Noted, let 2 days go on, krausen has halved in size, reading still 1.040. Took a reading today (2 more days later, now day 9 in primary), still 1.040. I'm thinking this is a combo of messing up mash temps, pitching yeast too warm, letting ferm temp get too high, and possibly not aerating the primary enough.

Anyways, I bit the bullet and got some amylase enzyme. Put 1.5tsp of AE into the wort, along with 1.5tsp of yeast energizer. 2 hours later and I'm seeing airlock activity - about a bubble per minute. This is not conclusive evidence of restored fermentation, but it's a sign. I have another packet of Nottingham on standby, but I'm going to let this run its course for probably a week or two and I will report back. I'll be happy with anything lower than 1.020 probably.

Thanks to everyone in this thread for the information!

 

[ten80]

... but I'm going to let this run its course for probably a week or two and I will report back. I'll be happy with anything lower than 1.020 probably.

I suggest swirling the fermenter a couple of times a day to rouse the yeast and get it back in contact with the wort!

 

[alexjames23]

I suggest swirling the fermenter a couple of times a day to rouse the yeast and get it back in contact with the wort!

Good advice. I gave the fermenter a good (but gentle) swirl right after putting the AE in. I'll consider swirling it some more but I'm not sure if it's necessary.. I woke up this morning to see the airlock bubbling out the top - bubbling every 5-10 seconds. Amazing! My initial target FG was 1.017, I'm very curious to see if it'll stop at target attenuation, +/-.002, for the beer's sake and as a good experiment.

 

[passedpawn]

Good luck. Note: bubbles don't always mean fermentation. Changes in temperature, nucleation points in the form of the AE powder itself, agitation of the fermentor, changes in pressure due to weather or merely removing the fermentor airlock - these things can all result in bubbles. Presence of a new krausen is a pretty good indicator.

Looking forward to hydrometer measurements.

 

[alexjames23]

Took hydrometer reading yesterday, which was 4 days after adding some AE: 1.022! That's an 18 point drop, and still a small krausen + bubbling. Will continue to monitor and report back when ferm is complete. I must say I'm pretty amazed. I won't rely on it my brews, but certainly a good tool to add to the toolbox.

 

[htownbrewer]

I'll go ahead and add to this epic 10 year old thread...

I have a english porter that had an OG of 1.057 and a target FG of 1.016. It has been stuck at 1.028 for 12 days. I tried rousing the yeast, warming the carboy and pitching more yeast, but nothing is moving the needle. I am going to give AE a try and see what happens. One question: Should I use Alpha Amylase or Amylase Enzyme Formula? Not sure if the latter is just a mix of alpha and glucose?

 

[passedpawn]

I'll go ahead and add to this epic 10 year old thread...

I have a english porter that had an OG of 1.057 and a target FG of 1.016. It has been stuck at 1.028 for 12 days. I tried rousing the yeast, warming the carboy and pitching more yeast, but nothing is moving the needle. I am going to give AE a try and see what happens. One question: Should I use Alpha Amylase or Amylase Enzyme Formula? Not sure if the latter is just a mix of alpha and glucose?

They are the same. So, yes.

 

[htownbrewer]

Update on my fermentation that finished higher than projected:

20 days into the fermentation (12 days after the gravity reading stalled out at 1.028), I added 3/8tsp of alpha amylase, swirled the wort, and left it to go to work.

2 days later, the reading was still at 1.028, so I added another 1/4tsp of AA. I swirled a bit more vigorously this time.

4 days later the reading was still at 1.028. I checked my hydrometer against some distilled water, and it read 1.000.

For the last 10 days I have had the temperature at the upper end for this yeast strain, which is 71degF.

After a total of 29 days in the primary fermenter, I went ahead and transferred the wort to a secondary carboy, as I didn't want it to sit any longer on top of the old yeast.

What I am planning to do next is to get some more yeast (I'm using WLP013 for this recipe), make a yeast starter and pitch it at high krausen.

Note that this is a chocolate porter, which called for adding 4oz of dutched cocoa powder to the boil. I strained a good bit of this out, but there was quite a bit that had settled into the bottom of the fermenter. I left this behind in my transfer. Due to the chocolate, it was hard to tell if there really was a good amount of yeast cake or not. It just seemed like chocolate mush. Also note, that when I first pitched the original yeast, I felt that the starter I had created did not result in much yeast being created. Also, my second yeast pitch was just a straight White Labs pitchable yeast pack. Thus it is possible that I have yet to pitch a healthy amount of yeast into this batch.

What I'm wondering is if I should add some more AA, and if so, should I do it before adding the yeast or after? My thought is to make sure I pitch enough yeast and see what happens with that first.

 

[passedpawn]

More yeast

 

[andrewmaixner]

In my experience, Alpha Amylase doesn't do anything in finished / stalled wort. I've tried it several times.
Amyloglucosidase will dry it out like magic, but will probably take it too far.
I would taste your beer cold and carbed first to see if it's just fine, before deciding to change your next yeast pitch to a highly attenuative, or even a diastaticus, strain.

 

[OldDogBrewing]

In my experience, Alpha Amylase doesn't do anything in finished / stalled wort. I've tried it several times.
Amyloglucosidase will dry it out like magic, but will probably take it too far.
I would taste your beer cold and carbed first to see if it's just fine, before deciding to change your next yeast pitch to a highly attenuative, or even a diastaticus, strain.

I think I read somewhere that when added to the fermenter Amylase is less efficient than Amyloglucosidase so maybe Amylase needs a fresh pitch of yeast