Stuck fermentation? Home brewing beer from kit that supplied malt, yeast and hops

10 views
Skip to first unread message

NY

unread,
Sep 13, 2020, 1:17:45 PM9/13/20
to
This is my first attempt at home brewing. I'm brewing cream stout from a kit
(St Peters) which supplied the malt, yeast and hops.

I made sure that the wort was below 25 deg C before I added the yeast and
the hops (which meant waiting a few hours because the recommended amount of
boiling water to tap water resulted in about 28 deg C).

After adding yeast, SG was initially 1040 and temp was 24.5 deg C.

After about 24 hours, fermentation had begun: I didn't see any CO2 emerging
from the water trap but maybe the lid of the fermentation bin doesn't fit
too well. However there was a lot of froth on the surface.

3 days after adding the yeast, SG had gone down to 1023. But on the 4th and
5th days it is still 1023. The temperature for all three of those readings
has been 19.4. There is now very little of the froth left.

It looks as if fermentation may have stopped. I gather this is described as
"stuck fermentation".

The instructions say to wait until 5-7 days, by which time SG should have
dropped to "below 1014", so I'm not giving up until a week from adding the
yeast, but it's looking as if there's a problem.


Does anyone have any suggestions? I've tried to be so careful to sterilise
the jug that I use for taking a sample, the measuring cylinder and the
hygrometer - and then to rinse them thoroughly before come in contact with
the beer. Likewise I sterilised and then rinsed the fermentation bin before
adding the viscous malt and then the boiling/tap water. Could I have got
some sterilising solution into the wort - could that have killed the yeast?
Is it worth "rousing" the yeast by stirring to include any sediment on the
bottom?

Or am I worrying over nothing: is it too soon to panic?


Baloonon

unread,
Sep 14, 2020, 8:36:25 PM9/14/20
to
"NY" <m...@privacy.invalid> wrote in news:rjlk7m$84k$1...@dont-email.me:
First, calibrate the hydrometer -- this is a guide.

https://blog.eckraus.com/calibrate-homebrew-hydrometer

The author describes his being off by 5 points. It's possible a faulty
measurement is the only problem.

If it is OK, was it malt extract or all grain? Extract usually ferments
fully unless there is a yeast issue, all grain can have problems if the
mash temperatures are off and never ferment to the predicted level..

1023 is high but sometimes fermentation slows down a lot after a few days
and lack of airlock activity, if you're using one, isn't always a sign that
it's stopped.

I would give it about another week and check again, just make sure to keep
the temps about where they are.

If you can, buy a fresh packet of the same yeast. Sometimes yeast in kits
can get pretty old and not ferment well. You may not need it, so if you
don't, store it in the freezer. If you can't get the same, try something
neutral like Nottingham.

If the gravity has barely budged or remained the same after the extra week,
try adding the fresh yeast. If it has gone close to 1014 and measures
stable over a few days, then it's done.

Another option if the extra time hasn't helped is to sanitize a spoon and
gently stir to minimize any air bubbles.

Adding more yeast or rousing the existing yeast may take a week for any
further fermentation to occur. Confirm with hydrometer measurements, don't
just assume it has stopped.

If you bottle, and the gravity doesn't drop, consider using less priming
sugar, and be careful about bottle bombs which occur when there are a lot
of unfermented sugars in a bottle. The broken glass and foaming can be kind
of scary.

Bill O'Meally

unread,
Sep 14, 2020, 8:39:11 PM9/14/20
to
On 2020-09-13 17:17:23 +0000, NY said:

> This is my first attempt at home brewing. I'm brewing cream stout from a kit
> (St Peters) which supplied the malt, yeast and hops.

Welcome to the group (what's left of it!), and to a most rewarding, and
sometime frustrating hobby!

>
> I made sure that the wort was below 25 deg C before I added the yeast and
> the hops (which meant waiting a few hours because the recommended amount of
> boiling water to tap water resulted in about 28 deg C).
>
> After adding yeast, SG was initially 1040 and temp was 24.5 deg C.
>
> After about 24 hours, fermentation had begun: I didn't see any CO2
> emerging from the water trap but maybe the lid of the fermentation bin
> doesn't fit too well. However there was a lot of froth on the surface.

Describe your "bin" please.

>
> 3 days after adding the yeast, SG had gone down to 1023. But on the 4th and
> 5th days it is still 1023. The temperature for all three of those readings
> has been 19.4. There is now very little of the froth left.

Sounds about right, as far as the diminished activity....

>
> It looks as if fermentation may have stopped. I gather this is
> described as "stuck fermentation".
>
> The instructions say to wait until 5-7 days, by which time SG should have
> dropped to "below 1014", so I'm not giving up until a week from adding the
> yeast, but it's looking as if there's a problem.

Maybe just give it more time. Check the SG every 2-3 days. If no
change, yes, likely a stuck fermentation.

>
>
> Does anyone have any suggestions? I've tried to be so careful to sterilise
> the jug that I use for taking a sample, the measuring cylinder and the
> hygrometer - and then to rinse them thoroughly before come in contact with
> the beer. Likewise I sterilised and then rinsed the fermentation bin before
> adding the viscous malt and then the boiling/tap water. Could I have got
> some sterilising solution into the wort - could that have killed the yeast?
> Is it worth "rousing" the yeast by stirring to include any sediment on the
> bottom?

What's the sterilizing solution you use? Whatever it is, I doubt it
would kill the yeast, especially once you've seen a vigorous
fermentation. You might want to consider repitching the yeast, if the
strain is known. The ingredients in these kits can be rather vague.
Did you buy the kit from a local homebrew store? Why not ask the
proprietors, who are often an excellent source of knowledge.

>
> Or am I worrying over nothing: is it too soon to panic?
>

Perhaps. Good luck!

--
Bill O'Meally

Joerg

unread,
Sep 21, 2020, 5:31:06 PM9/21/20
to
On 9/14/20 5:36 PM, Baloonon wrote:
> "NY" <m...@privacy.invalid> wrote in news:rjlk7m$84k$1...@dont-email.me:
>
>> This is my first attempt at home brewing. I'm brewing cream stout from
>> a kit (St Peters) which supplied the malt, yeast and hops.
>>
>> I made sure that the wort was below 25 deg C before I added the yeast
>> and the hops (which meant waiting a few hours because the recommended
>> amount of boiling water to tap water resulted in about 28 deg C).
>>
>> After adding yeast, SG was initially 1040 and temp was 24.5 deg C.
>>
>> After about 24 hours, fermentation had begun: I didn't see any CO2
>> emerging from the water trap but maybe the lid of the fermentation bin
>> doesn't fit too well. However there was a lot of froth on the surface.
>>
>> 3 days after adding the yeast, SG had gone down to 1023. But on the
>> 4th and 5th days it is still 1023. The temperature for all three of
>> those readings has been 19.4. There is now very little of the froth
>> left.
>>

19.4C may be a bit on the cold side if a fermentation has become
sluggish. Fermentis states up to 28C for US-05 yeast. If you used other
yeast and have already thrown away the pouch you can look it up online.
Most have a PDF specifications sheet.


>> It looks as if fermentation may have stopped. I gather this is
>> described as "stuck fermentation".
>>
>> The instructions say to wait until 5-7 days, by which time SG should
>> have dropped to "below 1014", so I'm not giving up until a week from
>> adding the yeast, but it's looking as if there's a problem.
>>
>> Does anyone have any suggestions? I've tried to be so careful to
>> sterilise the jug that I use for taking a sample, the measuring
>> cylinder and the hygrometer - and then to rinse them thoroughly before
>> come in contact with the beer. Likewise I sterilised and then rinsed
>> the fermentation bin before adding the viscous malt and then the
>> boiling/tap water. Could I have got some sterilising solution into the
>> wort - could that have killed the yeast? Is it worth "rousing" the
>> yeast by stirring to include any sediment on the bottom?
>>
>> Or am I worrying over nothing: is it too soon to panic?
>
> First, calibrate the hydrometer -- this is a guide.
>
> https://blog.eckraus.com/calibrate-homebrew-hydrometer
>
> The author describes his being off by 5 points. It's possible a faulty
> measurement is the only problem.
>

The worst I've found was 3 points off, but 10-15 points like in NY's
case seems high.


> If it is OK, was it malt extract or all grain? Extract usually ferments
> fully unless there is a yeast issue, all grain can have problems if the
> mash temperatures are off and never ferment to the predicted level..
>
> 1023 is high but sometimes fermentation slows down a lot after a few days
> and lack of airlock activity, if you're using one, isn't always a sign that
> it's stopped.
>

Could also be a leaky fermenter lid, then the airlock quits once the CO2
generation is low because CO2 hisses past the seal.


> I would give it about another week and check again, just make sure to keep
> the temps about where they are.
>
> If you can, buy a fresh packet of the same yeast. Sometimes yeast in kits
> can get pretty old and not ferment well. You may not need it, so if you
> don't, store it in the freezer. If you can't get the same, try something
> neutral like Nottingham.
>

Sounds like very good advice.


> If the gravity has barely budged or remained the same after the extra week,
> try adding the fresh yeast. If it has gone close to 1014 and measures
> stable over a few days, then it's done.
>
> Another option if the extra time hasn't helped is to sanitize a spoon and
> gently stir to minimize any air bubbles.
>

What I sometimes do is rock the fermenter, letting stuff slosh around in
there a bit. A couple of minutes ought to do it.


> Adding more yeast or rousing the existing yeast may take a week for any
> further fermentation to occur. Confirm with hydrometer measurements, don't
> just assume it has stopped.
>
> If you bottle, and the gravity doesn't drop, consider using less priming
> sugar, and be careful about bottle bombs which occur when there are a lot
> of unfermented sugars in a bottle. The broken glass and foaming can be kind
> of scary.
>

Oh yeah! I've got some horror stories there. At 1.023 FG I would not put
any sugar in there and also leave a lot more air space in the neck of
the bottles. Be careful, exploding bottles can cause great harm.

--
Regards, Joerg

http://www.analogconsultants.com/
Reply all
Reply to author
Forward
0 new messages