Escape from Stuck Fermentation Mountain - AE to the Rescue!

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htownbrewer

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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?
 
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passedpawn
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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

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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.
 

andrewmaixner

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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

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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
 
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