fermentation is stuck, not sure how to fix it

Hello,

I have prepared a cream stout about 2 weeks ago, the brew day went horribly wrong and it ended up having a mash temp of above 160 almost a full hour. fearing a low efficiency and since the wort didn't taste sweet at all, i added 1lb of corn sugar and 1 lb of honey to give it a little kick.

i took a gravity reading at the start and it read around 1.070. i may have recorded an incorrect gravity reading, because i was pretty drunk. i can taste some alcohol in it as it stands, so i know it fermented a little.

at 1 week, the gravity read 1.045, so i figured it was off to a good start. however, there was no visible krauzen at any time... a little scum ring around the side of the carboy was there, and the airlocked was bubbling for a few days, so i thought it was O.K.

well, it's now 2 weeks and the gravity reading today still says 1.045. i tasted it and it has a slightly sour, not so good taste... i expected an off flavor from the high mash temp, though. smells like beer, coffey, and a gym sock.


so, now i'm not sure what i should do. i suspect that i failed to properly aerate the wort at pitching time. i shook it up for about 30 seconds, much less than my previous batch which turned out great.

i looked it up and oxygen can hurt the beer now that's its fermented.

should i get some yeast nutrients and swirl the wort around?

how much vigor can i put into one of these "swirls" i've been reading about?

I appreciate any input you guys can offer!

Thanks,

Adam

Swirl it. The yeast nutirent won't hurt. You can get pretty vigorus with the swirl. You are trying to remix the yeast from the bottom into suspension.

What temp were you fermenting at?

I just noticed your mash temp. You might want to pitch some EC1118 in there to eat up any possible fermentables. A mash temp of 160 is going to be pretty damn high in unfermentables.

On the other hand you might just want to bottle it. It will make a sweet stout. What was the recipe?

it doesn't taste very sweet at all right now, it tastes more sour than sweet. i would not find a carbonated version of what it is right now enjoyable.

it was an all grain kit from northern brewer.

I'll look into this new type of yeast and get some yeast nutrients.

my fermentation temp. is 162-164 with nottingham dry yeast packet.

thanks for the info on the swirling..didn't realize i was trying to stir up the yeast cake...would it better to stick a sanitized mash paddle in there and stir it up?


i hope it turns out at least drinkable!

oh, i had another question.


is it a good idea to add lactose to the bottles individually at bottling time? i wanted to add another 1lb of it at bottling time, but i use a primary with a spigot..basically i thought if i mixed the sugar in, it would fall and settle on top of the yeast cake.

Kinda odd that it tastes sour but not sweet. Could be yeast bite though. Itake it you meant 62-64F fermentation not 162-164?

With that OG I'm suprised it is not sweet already.

yeah, it never tasted sweet to begin with, but it wasn't sour. do you think it could be infected?

Probably not. Do the swirl thing and give it some time. Regardless of your mash temp, that was a fairly big beer anyway, and could use some extra time and TLC.

Use Lactose if you want to raise that FG up by a bunch. Otherwise that is the last thing you want.

I'm betting that you got no conversion because you never activated the enzymes that would do the conversion. They are activated between 146 and 159 for saccharification. They are denatured at 168.

Bacause you were at 160 for the duration they never would have created sugar to be fermented and the wort would not taste sweet. By adding sugar and honey you gave the yeast some small quantity of sugars to munch on. The remainder of the gravity was starches dissolved in solution.

I'll bet stirring and yeast nutrients will do little or nothing. On the other hand some amylase enzyme would convert that starch to sugar to some degree and you might get somewhere.

This is all assuming that you meant 62-64 for fermentation NOT 162-164.

At 160 there will be beta and alpha activity, but mostly alpha. That is actually the prime temp for Alpha amylase.

dontman- yes, that makes sense to me.. i think i'll get some of that starch enzyme and throw it in there. i gave it a swirl anyway, though.

its definitely chillin at 62-64.

thanks for your help guys! i hope to be able to drink this beer

Alpha Amylase 155 - 167°F

You could use some beano, which will break up the unfermentables into fermentable sugars, but you can not stop this action without raising the temp up to 170f + and could lead to bottle bombs and dry beer otherwise.

I would recommend that you raise your fermentation temp to 68-70, depending on the yeast that you used. Gee, I was just checking, and some of the lager yeast ferments as high as 58 F! some of the ales as high as 76F! See if your yeast is here: NORTHERN BREWER: Dried Yeast

and raise your temp. Don't raise your temp much more than 1-2 degrees a day. I don't know why thats important, but it sure sounds smart. Maybe someone else knows.

while Alpha might still be active at +160 active enzyme equals conversion to sugar which equals sweet wort. Therefore non-sweet wort is a very definite sign that conversion has not occurred, active enzyme or no.

But don't use beano for the reasons Denny brings up. Use amylase enzyme. This is a much more controlled reaction. Buy it at your LHBS.

Did you do an iodine test on the mash runnings?

i got some amalyse and i'll throw it in there in the next few days.


i used danstar nottingham dry yeast.

i did not take an iodine test of the mash runnings. . . never got any iodine.

is 155-167 the temp i need to keep the wort while the enzyme does its work?

see chart I posted above. (post 11)

misteradam said:

i got some amalyse and i'll throw it in there in the next few days.


i used danstar nottingham dry yeast.

i did not take an iodine test of the mash runnings. . . never got any iodine.

is 155-167 the temp i need to keep the wort while the enzyme does its work?

Click to expand...

Denny, your chart is not applicable to adding amylase to restart a ferment. That is for mashing.

No you do not need to reheat your beer at this point for the amylase that you purchased to do its work. This is not the same as when you are mashing. Just follow the directions.

EDIT: Unless I am reading your question wrong. If you are asking about mash temps for future reference, then definitely refer to Denny's chart in post 11.

dontman said:

Denny, your chart is not applicable to adding amylase to restart a ferment. That is for mashing.

No you do not need to reheat your beer at this point for the amylase that you purchased to do its work. This is not the same as when you are mashing. Just follow the directions.

EDIT: Unless I am reading your question wrong. If you are asking about mash temps for future reference, then definitely refer to Denny's chart in post 11.

Click to expand...

Actually amyalase is made up of beta and alpha amylase so it is relavent.

That said. At room temp there will be slow beta activity so if your mash did not convert, the beta should convert the starches now.

I'm just having a hard time believing there was little converison in the first place. A mash of 160f should have converted to non-fermentables in less than 15-20 minutes.

Anyway, the beta amylase can and will break down the dextrins that the alpha produced. The problem is, you have no way of stopping that activity without denaturing the enzymes. So, you could end up with bottle bombs in the future unless you raise the beer up to 170F at some point.

denny- almost the entire mash, it was above 160, almost at 170. i freaked out and threw a bunch of ice cubes in it, removed it from heat, but it still took 30 minutes to get down to 160, and in the final 20 minutes of an hour period it went down to 155.

what happened was i actually hit a mash temp of 158 perfectly, but i got really paranoid, over thought it and turned the heat up, thinking it needed to be at 170.

i think whatever sugars are in there are from that initial period of correct temp..probably 5 minutes or so, plus the honey and corn sugar.


- so after i add the enzymes, can i let it ride in the low 60's for another week before raising it above 70?

how long should i keep it at 70 before bottling?

Denny's Evil Concoctions said:

I'm just having a hard time believing there was little converison in the first place. A mash of 160f should have converted to non-fermentables in less than 15-20 minutes.

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I agree with this except for the fact that his wort did not taste sweet. Fully converted wort is really sweet. I'm actually thinking his wort must have been higher temp than 160. It explains everything that has happened since.

As far as denaturing this amylase addition (by raising the beer to 170) it should not be necessary. The stuff he bought is not like beano. It does not go out of control and only stop when the beer is at .0096. As long as he follows directions and waits until the fermentation fully stabilizes at FG for at least a week.

OK, I think you said it ws at 160 not near 170. In that case you're probablt correct.

Dontman, if the beer had hiogh unfermentables from alopha then beta will munch it till it's mostly fermentable.

If it's unconverted starch then at those temps you are probably correct.

sorry to confuse you guys, im pretty sure it was between 160-170, probably closer to 165 for the majority of the duration. the wort definitely did not taste sweet, especially compared to the other brew i have done.

just want to say thanks to you guys, i really appreciate the info!

i threw in some amylase in there today. it didn't specify how long to leave it in there on the packaging, but i read somewhere else to pitch it with the yeast.

its in the third week of fermenting right now, so i don't want to leave it alone for more than 4 weeks.

should it be cool to leave it in there for just 1 week? its getting warmer out, so the fermentation temp may get up to 170-172 anyway.

does anyone know what kind of off flavors i should expect for abusing my beer so much?

thanks!

If your ferment hit 170 then the alcohol would all evaporate and your beer would be completely destroyed. Luckily that is impossible since the yeast will die well before then.

Just let it ride until the fg stabilizes for a week or so. No need to mess with the temp too much because it was never too low to shock the yeast into dormancy.

i keep adding a hundred degrees to the temps i'm typing

the fermentation has reached 74 when i checked it this morning.. should i pitch more amylase after i can get it cooled?

Prpabaly no more amylase is necessary. Just let it ride. I wouldn't even bother looking at it for at least a week to ten days. Then take a reading, then wait three days, if the reading is the same then you should be at terminal gravity.

the amylase seems to have restarted fermentation.. it's bubbling now pretty steadily, and the carboy is in the low to mid 60's.

i'll check it at the 1 week mark like you suggested and see how far along it's gotten.

does anyone know why it had no kreuzen?

misteradam said:

does anyone know why it had no kreuzen?

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You said it had a scum ring right? If so then that was remnants from the kreuzen. Wort is very private and doesn't perform so well when being watched. Let the yeasties and the wort do their own thing for awhile and don't get hung up on kreuzen. Just because you didn't see it doesn't mean it wasn't there.