Escape from Stuck Fermentation Mountain - AE to the Rescue!

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Makes me want to try a cold brew mash. Just gargle some starsan before drinking. Seriously though, You'd think you could dominate the natural flaura by using an ultra low temp Sac. or other and strictly controlling the temps?
You still need a hot mash to solubilize the starches (large sugar molecules). Otherwise the enzymes can do nothing.
 

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So 24 hours later and ..... Nothing. A few extra bubbles that haven't grown since this morning. Looks like this now barleywine will be great thanksgiving. Thanksgiving 2016
 

Brettomomyces

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Jumping onto this thread as I have two beers going with amylase right now.

First beer was an alt that I brewed with the intention of step mashing at 144, 158 and 168. I have an e-herms rig, and my water pump cut off unexpectedly during the mash so the heating element kept rising as the wort pumped through the herms coil. I got 45 minutes at 144 and then it rose all the way to 172 over about 35-40 minutes, so not a lot of time for a beta rest. 6L starter of wlp036, which was about 70% viability but I was also shooting for a hybrid pitch rate and made plenty of yeast. O2 with my oxygen concentrator. OG was 1.051, held at 14.5C for three days then raised to 21C over 5 days, held there another 5. FG at 1.016. Not low enough!!

Added 2tsp of amylase and 2tsp of yeast energizer. Chamber is now at 17.5C after a slow fall.

Second beer is an english barleywine. Fair amount of crystal malt but not over the top, and some home made candy syrup as well (from the sugar + DAP thread in the recipes section). 1.106 down to 1.029, but could be dryer. 73% with wyeast 1968. This beer did not get O2 (machine wasn't working) but was pitched onto a cake from a 1.058 oatmeal stout and got regular aeration. I added 1tsp amylase and 1tsp energizer for 5gals. I can already see krausen forming on one of the barleywines and airlock activity in both after 8 hours. Will report results when these stabilize.
 

Brettomomyces

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Ok the followup!

The altbier went down significantly. After 3 days it had dropped 3 points. After 7 days it had gone down 10 points! Way more than I was expecting.

So my impression on it overall though, is that the malt flavor feels less strong than I remember but the overall beer is not thin or watery, it still has a decent mouthfeel to it and is now significantly drier and more bitter. I would imagine the 10pt drop just upped the bittering impact significantly. The body and mouthfeel of it really surprised me though, as I waited until after the hydro sample to get a taste. I'm letting nature crash cool it for me in the garage until Saturday and then gelatin fining this batch.

On the barleywine, no change. I'm counting this up to not enough viable yeast available because they were in secondary for a week at that point. I don't necessarily feel too bad about it though, after seeing the results on the Altbier. I still see some bubbles on one of the carboys that I originally mistook for krausen but must simply be gas blowing out from the addition of the nutrient/amylase. They are both still showing slow airlock activity as well. This is 5' under and in a cool but stable temperature location.

Altbier gravity.JPG
 
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Ok the followup!

The altbier went down significantly. After 3 days it had dropped 3 points. After 7 days it had gone down 10 points! Way more than I was expecting.

So my impression on it overall though, is that the malt flavor feels less strong than I remember but the overall beer is not thin or watery, it still has a decent mouthfeel to it and is now significantly drier and more bitter. I would imagine the 10pt drop just upped the bittering impact significantly. The body and mouthfeel of it really surprised me though, as I waited until after the hydro sample to get a taste. I'm letting nature crash cool it for me in the garage until Saturday and then gelatin fining this batch.

On the barleywine, no change. I'm counting this up to not enough viable yeast available because they were in secondary for a week at that point. I don't necessarily feel too bad about it though, after seeing the results on the Altbier. I still see some bubbles on one of the carboys that I originally mistook for krausen but must simply be gas blowing out from the addition of the nutrient/amylase. They are both still showing slow airlock activity as well. This is 5' under and in a cool but stable temperature location.
OG/FG please. Thanks.
 

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Altbier 1.051 to 1.016 to 1.006 after amylase

Barleywine 1.106 to 1.029. No change after amylase. Barleywine was also a few weeks older than alt and in secondary.
 
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Altbier 1.051 to 1.016 to 1.006 after amylase

Barleywine 1.106 to 1.029. No change after amylase. Barleywine was also a few weeks older than alt and in secondary.
Regarding the altbier, that sounds about what I'd expect. See this. Thanks for the response.

Add fresh yeast to the barleywine. Please report back what happens.
 

Brettomomyces

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I think a definite conclusion from my trial is that the quantity of enzyme required is less than anticipated. I achieved a result of roughly 88% ADF with my addition of enzyme, at 1tsp per 5 gals.

On the barleywine, I think I will leave one carboy as is and pitch some slurry into the other. I have some pretty fresh slurry from a high attenuating English strain (custom blend from Inland Island for my LHBS, Quirky's).

The resultant body on the altbier was surprising to me, as it was not nearly as thin as expected. Being that the enzyme is alpha amylase, is it possible that the enzyme created some dextrins in the process that are adding to body/mouthfeel?
 
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I think a definite conclusion from my trial is that the quantity of enzyme required is less than anticipated. I achieved a result of roughly 88% ADF with my addition of enzyme, at 1tsp per 5 gals.
I asked my nerdy son about this today. He's only 18, but he's pretty good at chemistry and biology and stuff like that. Here's our exchange (email, he's off at college). Not sure what to make of all this, but when he comes home in a week he's going to show me the math apparently. Uh oh. :drunk:

Me: Are enzymes "consumed"? That is, let's say I have 10 starch molecules, and I add 10 alpha amylase enzymes molecules that somehow reduce the starches to glucose or sucrose or something. Now, are those enzymes free now to work on some other starch molecules, or are they "spent"? That's what I wonder.

Alex: The substrate will bind with the enzyme by coming into its active site, and the affinity for the substrate to bind depends on a number of factors. Then the enzyme will use different methods of catalysis such as acid-base or nucleophilic catalysis to reduce the substrate into some type of product. The enzyme then goes back to its original chemical composition and state and is ready for catalysis once again. Hope this helps.

Me: Holy cow that's cool. So an enzyme can work more than once. I guess the rate of enzymatic activity is much higher if you use a lot more though.

Alex: Yeah if you want the maximum velocity of the enzyme, you use as much substrate as possible, like totally flood the enzyme with substrate. It's funny because I learned how to mathematically derive the concepts we're talking about right now. So it's not just theory or conversation, I can prove it ;)

Me: I'd like to see that when you come home. Show me how to do it.

Alex: Haha okay. I can tell you what the equation is and you can try to look it up. "Michaelis-Menten equation". It'll be easier when I show you though, it's pretty long and complex.
 

ten80

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Sounds right. Enzymes are not consumed, degraded, and do not loose enzymatic potential in an ideal system. Our beers are not quite an ideal system because there are yeast and other organic compounds in solution that may cause the enzymes to denature or precipitate out of solution, plus the beer may not be at the ideal temperature or pH for optimum enzyme activity.

These factors play into the Michaelis-Menten equation and the resulting "Vmax" or theoretical maximum rate of enzymatic activity. However, you must consider that this equation relates to enzyme activity rate and not the extent to which an enzyme will degrade a certain starting concentration of a substrate. In other words, even an enzyme with a low Vmax will eventually catalyze the degradation of a high concentration substrate, assuming that the enzyme is not denatured or removed from solution.

I have the EVEREST of stuck-mountain fermentations. I accidentally brewed a stout using 32 lbs of ADJUNCT MALTS with little to no base malt. Mashed at 154F for an OG of 1.065, and the FG was 1.035 after 1 month. It is thick, black and syrup-like in consistency. The fun part is that I brewed 12 gallons "thick-bodied" stout.

This seems like a great place to post my results. I have little to lose by adding amylase enzyme and a fresh yeast starter. Will it be drinkable? I suspect it will be a roast-bomb!
 

eigua

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This seems like a great place to post my results. I have little to lose by adding amylase enzyme and a fresh yeast starter. Will it be drinkable? I suspect it will be a roast-bomb!
Did you end up using the amylase to try to rescue this?
 

55x11

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I accidentally brewed a stout using 32 lbs of ADJUNCT MALTS with little to no base malt...

This seems like a great place to post my results. I have little to lose by adding amylase enzyme and a fresh yeast starter. Will it be drinkable? I suspect it will be a roast-bomb!
Wait, how did you manage to do this? What is your grain bill?
Please share!

You could always call it "bitter barley soda".
 

ten80

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Wait, how did you manage to do this? What is your grain bill?
Please share!

You could always call it "bitter barley soda".
Funny story... I bought a bunch of brewing equipment on craigslist and the guy also gave me a "bag of malt for a stout recipe that I have forgotten." I knew something was terribly wrong when I essentially had roasted barley syrup after mashing. I ended up with something like 12 gallons of 1.060 OG squid ink that stalled at 1.030. As far as I can tell I brewed a beer with over 30 pounds of roasted barley and crystal malts!

I split the 12 gallons into two carboys. To the first I added an active sour beer culture in one half (Brett, pedio, lacto, etc) and it dropped the FG to 1.021 after 10 months (last week). Drinkable, but damn dark and the roast overwhelms the funk. I blended some of this into a Kriek-style sour at 10% by volume and the result is a spectacular dark fruity sour. The remainder was blended with 5 gallons of plain 2-row wort (still fermenting).

I added a heaping 1/3 cup of amylase enzyme to the second half and then added some active US-04 yeast krausen. I have yet to test the FG on this half, but I suspect it dropped substantially due to the visible fermentation activity that ensued. The question is whether the beer will be drinkable and free of infection! I hope to post an update in the next month or so.

NOTE FOR AMYLASE USERS:
Amylase enzme is produced in an industrial fermentation and I have read from several sources that the enzyme powder may contain bacteria and that it is best to use amylase prior to boiling to avoid the risk of infecting your beer. That said, you are probably OK adding amylase enzyme once the pH of the beer has fallen below 4.5 pH units and there is >3% alcohol present.

Has anyone experienced contamination of their beer following addition of amylase enzyme?
 
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This thread saved my altbier.

My FG was stuck at 1.021 for weeks with a target of 1.014

Having unsuccessfully tried every combination of rousing, temperature increase & re-pitching, the OP guided me to this thread. My LHBS recommended a product called Pilsner Enzyme for the task. I can't confirm, but I'm guessing this is just a branding term for Alpha Amylase Enzyme. The advice provided here has achieved instant results in relation to reaching my target FG. Three days after the enzyme addition, my FG is at 1.014, which is exactly where it is supposed to be. I have not packaged the beer yet, so the results are purely technical at this point.

I hope I never have to use this technique again, as it highlights an error in my mash process. Knowing that there is a solution is priceless, however.
 
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One week in and the gravity has dropped further still to 1.010

This is not ideal. The target was 1.014

Added to this, fermentation also appears to be ongoing. Now I'm concerned the altbier will be too dry with a bitter bias.
 
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One week in and the gravity has dropped further still to 1.010

This is not ideal. The target was 1.014

Added to this, fermentation also appears to be ongoing. Now I'm concerned the altbier will be too dry with a bitter bias.
I think it will ferment 85-90% (assuming that was AA you added). That gets you to ~ 1.007 ish.

But I make beers that finish nearly that low and they are fine after full carbonation. I have an IPA on tap right now at 1.007, but I don't think you'd know it. My pilsners finish down there.

In Dusseldorf, there are a bunch of altbier breweries, and they all brew different altbiers. Eurige is the most popular one (they pile hot steaming spent grains outside the brewery in the street, and you can smell from blocks away). Theirs alt on the bitter side.
 
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passedpawn said:
I think it will ferment 85-90% (assuming that was AA you added). That gets you to ~ 1.007 ish.
Ok. Thanks for clarifying.

passedpawn said:
In Dusseldorf, there are a bunch of altbier breweries, and they all brew different altbiers. Eurige is the most popular one (they pile hot steaming spent grains outside the brewery in the street, and you can smell from blocks away). Theirs alt on the bitter side.
Uerige is the style I'm going for actually (with a touch of Füchschen). Sure, it has a firm hop bite, but also enough residuals to give it some body. My hop quantities were pushing the (beersmith) envelope already.
 
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One more data point: I added a tsp of AA to a light lager I made a couple of months ago. The AA was added right at the beginning of fermentation (I used a bunch of solubulized rice in the recipe, so I added enzymes to get complete conversion of those starches). Beer went from 1.045 down to about 1.008. The point I'm making is it did not over-attenuate with the AA.

The beer fermented at 50F and was finished at the 3 week mark, which is when I normally keg these.
 

ten80

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Ok. Thanks for clarifying.
Uerige is the style I'm going for actually (with a touch of Füchschen). Sure, it has a firm hop bite, but also enough residuals to give it some body. My hop quantities were pushing the (beersmith) envelope already.
You can bump the body back up with some malto-dextrin without affecting the flavor.
 

Cameron McKellar

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Long time lurker bumping this thread as I know find myself atop the stuck fermentation mountain! :no:

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!
 

ten80

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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!
 
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Long time lurker bumping this thread as I know find myself atop the stuck fermentation mountain! :no:

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.
 
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Cameron McKellar

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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

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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

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.....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.
 
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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/
 

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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.
 

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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.
 

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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).
 
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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.
 

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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

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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" :p 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).
 
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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" :p 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.
 

kh54s10

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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

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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

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... 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

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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.
 
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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

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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.
 
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