Slow Start On A Ferment ?

[The_Duck]

Hi All,

If there are no signs of ferment after 4 days can my yeast be declared clinically dead ?

The yeast was shipped down to Vic from Craft Brewer in QLD and still felt cool (had 2 techni-ice pack wrapped around the yeast, then bubblewrapped).

I re-hydrated the yeast a good 3 hours before the wort was finished and added some wort (@ ~28C) to the re-hydrated yeast.

I pitched the yeast into the fermenter @ 26c late at night based on temp drop it would/should kick off in the warm wort but it would be down to high teens within a few hours.

But I've seen nothing in the way of fermentation since pitching... going on 4 days now.

Thinking I may need to visit a LHBS and pickup another sachet and try again ?

 

[dabre4]

What kind of yeast is it Lager or Ale? What temperature is the wort at now? Yeast can be slow to start, particularly if you haven't made a starter.

The other answer could be simple, the yeast is doing its thing, but the CO2 is finding a way out around the airlock. I had this happen, tightend the lid, made sure the seal around the airlock o-ring was good, hey presto. What are you using for a fermenter?

 

[Fatgodzilla]

Hi All,

If there are no signs of ferment after 4 days can my yeast be declared clinically dead ?

Nottingham is a little slow for me but , yes, I'd be worried after 4 days of nothing. Give the wort one more good stirring and see what happens for a day. If nothing, go another yeast. Pitching at 28c shouldn't have been a problem but would prefer you didn't do that next time (Nott doesn't need re-hydrating IMHO) and 28c is a bit high (yeasts hate excessive temps)

Did you keep the yeast satchel - Ross at CB would want you to contact him with the details for quality control purposes. Email him with the details if you have them (serial numbers, use by dates etc).

 

[The_Duck]

Thanks for the speedy responses..

The yeast is a Danstar Nottingham Ale yeast, however I believe it likes to ferment low 10-20c.

I am using a std Coopers fermenter that just had a batch of dark IPA run through it with no issues. I'll check the seal on the fermenter again. Thing is I don't get any king of malt/hop aroma from the fermenter area which I normally do during ferment (Way better than a Glade Plugin !!)

I actually got 2 yeast packs in the same order as well as (2 Redstar Cotes du Rhone for making mead and experimental cider) so they may be from the same batch... but I did throw out the packaging for the one I used.

I have used possibly a generic version of this yeast before (marketed at my LHBS as a "Viking" yeast) and it says to re-hydrate in water 28-38c.

Cheers

 

[Screwtop]

Some questions:

1. Do you have fermentation temp control.......if so
..........What temp is the beer at now?
..........What temp does it get down to during the night?

2. Have you taken a gravity reading?

We tend to see this topic and variations repeatedly during winter.

Cheers,

Screwy

 

[The_Duck]

Some questions:

1. Do you have fermentation temp control.......if so
..........What temp is the beer at now?
..........What temp does it get down to during the night?

2. Have you taken a gravity reading?

We tend to see this topic and variations repeatedly during winter.

Cheers,

Screwy

The fermenter is wrapped in a double layer of polar fleece and sits on the floor right above where my central heating ducts run under the floor so it is usually warm the whole time.

I don't have any kind of sophisticated temp trending so I cannot faithfully say what level of temp fluctuations occur during the night.

I usually have an immersion heater I use for ales but I am using it in another brew right now.

I'll check the temps when I get home and re-post.


Cheers

 

[Steve]

I re-hydrated the yeast a good 3 hours before the wort was finished and added some wort (@ ~28C) to the re-hydrated yeast.

Why did you do this? Are you sure the wort you added to the re-hydrated yeast wasnt hotter than 28? (Not that you need to add wort to yeast). Is there no kruasen or condensation on the inside of the lid?

 

[The_Duck]

Why did you do this? Are you sure the wort you added to the re-hydrated yeast wasnt hotter than 28? (Not that you need to add wort to yeast). Is there no kruasen or condensation on the inside of the lid?

Hi Steve, quite sure.

This technique has been discussed in many places I have read over the last few years as it allows dried yeast to more gradually acclimatise to the wort before being dropped into it. The contents of the container with the re-hydrated yeast were quite cool so the 28c wort would have ended up as 20 deg yeast solution + wort.

I have found that using this method generally shortens the time to fermentation kickoff by at least 50% (<10 hrs) and sometimes ~70% (~6-8hours) all things being equal.

I can see no signs of condensation or krausen at all in the fermenter... but again.. I will check when I get home. You never know what happens at home while you are at work.

 

[warra48]

As mentioned, the usual signs of fermentation are condensation on the lid, and kraeusen on top of the brew.
Those things are signs only.
To be truly sure, you need to do a SG test, using your hydrometer.
What was your Starting Gravity, and where's your brew at now?

 

[The_Duck]

As mentioned, the usual signs of fermentation are condensation on the lid, and kraeusen on top of the brew.
Those things are signs only.
To be truly sure, you need to do a SG test, using your hydrometer.
What was your Starting Gravity, and where's your brew at now?

OG was 1050. I have been in the habit of taking a gravity reading after I have seen fermentation start and not before.

Based on some of the comments above I may need to re-think this practice as there may be no bubbling airlock/krausen/condensate etc if the seal on the fermenter lid or the o-ring for the airlock.

I'll post a "current gravity" tonight.

 

[Ross]

When you proofed the yeast, did it foam up in the container or just settle out on the bottom with no foaming?

Cheers Ross

 

[Screwtop]

I re-hydrated the yeast a good 3 hours before the wort was finished and added some wort (@ ~28C) to the re-hydrated yeast.

Some info here from Dr Clayton Cone of Danstar.

Here's the link for those interested, too much to post. Rehydrating Yeast - Dr Clayton Cone

Every strain of yeast has its own optimum rehydration temperature. All of
them range between 95 F to 105F. Most of them closer to 105F. The dried
yeast cell wall is fragile and it is the first few minutes (possibly
seconds) of rehydration that the warm temperature is critical while it is
reconstituting its cell wall structure.

As you drop the initial temperature of the water from 95 to 85 or 75 or 65F
the yeast leached out more and more of its insides damaging the each cell.
The yeast viability also drops proportionally. At 95 105 F, there is
100% recovery of the viable dry yeast. At 60F, there can be as much as 60%
dead cells.

The water should be tap water with the normal amount of hardness present.
The hardness is essential for good recovery. 250 -500 ppm hardness is
ideal. This means that deionized or distilled water should not be used.
Ideally, the warm rehydration water should contain about 0.5 1.0% yeast
extract

For the initial few minutes (perhaps seconds) of rehydration, the yeast
cell wall cannot differentiate what passes through the wall. Toxic
materials like sprays, hops, SO2 and sugars in high levels, that the yeast
normally can selectively keep from passing through its cell wall rush right
in and seriously damage the cells. The moment that the cell wall is
properly reconstituted, the yeast can then regulate what goes in and out of
the cell. That is why we hesitate to recommend rehydration in wort or
must. Very dilute wort seems to be OK.

We recommend that the rehydrated yeast be added to the wort within 30
minutes. We have built into each cell a large amount of glycogen and
trehalose that give the yeast a burst of energy to kick off the growth
cycle when it is in the wort. It is quickly used up if the yeast is
rehydrated for more than 30 minutes. There is no damage done here if it is
not immediatly add to the wort. You just do not get the added benefit of
that sudden burst of energy. We also recommend that you attemperate the
rehydrated yeast to with in 15F of the wort before adding to the wort.
Warm yeast into a cold wort will cause many of the yeast to produce petite
mutants that will never grow or ferment properly and will cause them to
produce H2S. The attemperation can take place over a very brief period by
adding, in encrements, a small amount of the cooler wort to the rehydrated
yeast.

Cheers,

Screwy

 

[felten]

Great read, what does he mean by 1% yeast extract though? I'm assuming its a yeast nutrient and not a big ol' teaspoon of vegemite

 

[The_Duck]

When you proofed the yeast, did it foam up in the container or just settle out on the bottom with no foaming?

Cheers Ross

After the re-hydration, it looks like most yeast went to ground... well bottom of the container and sat there.

After adding wort there was little to no activity from the yeast. Others I have done the same way bubbled like krausen, but I think they were SAF-04.

 

[The_Duck]

So I have had a look at the fermenter.

Temp 18c

Fermentation signs:
Condensation - Check
Foam on surface - Check
Airlock bubbling - Negatory
Krausen - Negatory

OG - 1050
Current Gravity reading 1022

Visual inspection of the fermenter shows a thin rim of condensation on the OUTSIDE of the lid seal possibly indicating a minute gap. I cranked the lid down and it went about 1/4 turn. Can't believe that 1/4 turn would make that much difference... but we'll see.

Taste of gravity sample....slightly bitter malty Irish Red Ale.

Maybe the 3 hours of re-hydration resulted in the good Dr's caution of only doing re-hydration 30 mins before pitching...and I need warmer water. 38C (98F) should be fine according to the Doc.

 

[Ross]

Sounds like everything is perfect & on track :icon_cheers:

Cheers Ross

 

[jakub76]

So I have had a look at the fermenter.

Maybe the 3 hours of re-hydration resulted in the good Dr's caution of only doing re-hydration 30 mins before pitching.

Sounds like your brew is fermenting just fine, I've also had lid/seal issues...scary right?

But I'd go the other way with your yeast, I'd say rehydrate miles earlier with a weak (1.040) wort and get a starter going. It's real easy, 50 grams DME in 500ml of water, really easy rule of thumb. When you see that yeast starter at high krausen it'll put your mind at ease. Do it first thing on brew day or the night earlier if you're brewing a lager...McGyver (works for me)