Cold shocking yeast?

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keke

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Hi,
I have recently brewed an IPA with s-04 dry english ale yeast, my O.G was 1066. I was planning on fermenting at 68F but my wort was a bit warmer around 73ish. So I pitched the yeast and in about an hour or two I saw a bit of airlock activity, however the wort still did not cool to the desired temperature. I was stressing to cool down the wort a bit more so I lowered my fermentation chamber to around 60 only for an hour or so to speed the cooling process a bit. When the wort got to 68 degrees I set the temperature back up to 68 but then the activity just stopped. I waited for around 8 hours but nothing has changed. I was shaking the bucket thinking I should rouse the yeast a bit but that also did not help at all. After that I just took out my fermentation bucket and left it at room temperature in my apartment (around 75F). And finally after a few hours airlock activity came back to life. How can this be? It says on the yeast pack that ideal temperature is 59F-68F and I was in that range. The same case happened to me a few weeks back when I brewed a Belgian wit with us-05 yeast. Is it possible that I am cold shocking the yeast when trying to cool temps allittle faster? What have I done wrong?

Any advise would be highly appreciated thank you!!!
 
The lids on the buckets don't always seal properly. What you're seeing is probably an extremely violent fermentation that's using the airlock instead of the leaky seal. You should probably get temps down so you don't start producing Fusels.
 
Are you using a temp controller? How are you monitoring your wort temperature?

If so, I'd recommend getting a stopper thermowell. You can drill or cut another hole in your bucket lid to make room. All you have to do is drop the temp probe in the well, set your temp and it'll do all the work for you, no hassle. Considering that fermentation is going to raise the temperature of the wort, I think it's a better way to go to ensure consistent temps instead of ball-parking it with constantly changing temp. My batches stay within 1 degree of my target temp throughout fermentation this way.

I don't think 60 degrees is enough to knock out the yeast, either...Maybe it could have slowed them down?

Also, keep in mind that airlock activity (or lack thereof) isn't necessarily an indicator of fermentation (or lack thereof).
 
I am using a temp controller. I ordered an stc-1000 from ebay and connected it to a fridge which is now my fermentation chamber. I brought the temp down to 65F and the airlock is still showing activity. It's just so weird what happened to me and I don't understand it. I was thinking maybe it was something else: I was shaking the bucket for a few minutes before pitching the yeast in order to oxidize the wort, so maybe the yeast was sitting on the foam that was created on top for a while until it settled and then the yeast started working? Does that make any sense?
 
Bring your wort to your intended fermentation temperature before or after pitching the yeast. It is better to pitch the yeast at or a little below the fermentation temperature though. Don't even think about doing anything to the fermentor for at least 36 hours. Lag times can be even longer with some yeast.
 
For future reference brewers are better off to wait till you can pith the yeast vs pitching while the wort is too warm. The reason being that most off-flavor precursors and actual off flavors are created early during the lag phase of fermentation and even during the low krausen. If a beer ferments hot during the high krausen you will get unwanted fruity esters. If you simply put your wort in a ice bath in the sink inside your fermenter it will cool down from say 80 to 65 in a few hours if you keep adding ice(assuming you lack the fridge/freezer space).
 
Guess what I was trying to say was if I had to choose between the two I'd prefer pitching into properly cooled wort and holding it there till high krausen then letting it go free vs pitching into hot wort then keeping it cool during high krausen. For truly good beer though you need to maintain proper temps throughout the whole process.
 
Where is your temperature probe?

It's in the fridge I taped it to the back of the fermentor so it is as close as possible to the actual wort, if that makes any sense...Why do you ask?
By the way thank you all for the reply's you're helping me a lot!
 
i think he meant- where do you have it sitting? is it taped to side of carboy? hanging free in the cold chamber? inside a thermowell measuring the actual wort temp?

all of those will get different temp readings.

also- you really should do the temperature calibration on the stc/inkbird/etc units. mine was off by like 2.5 degrees F. either get a reliable digital thermometer and use that to calibrate your temp sensor/controller, or pack a pint glass with ice, fill it with coldest tap water you've got, and in a few minutes it should basically be 32F and you can use that to calibrate your box.
 
It's in the fridge I taped it to the back of the fermentor so it is as close as possible to the actual wort, if that makes any sense...Why do you ask?
By the way thank you all for the reply's you're helping me a lot!


I recommend getting a stopper thermowell. It detects temperatures directly in the middle of the wort. In theory, it's more accurate than the probe taped to the side. It will also detect temp changes more quickly.View attachment ImageUploadedByHome Brew1443919872.627468.jpg
View attachment ImageUploadedByHome Brew1443919970.282270.jpg
 
I think you may have mistaken air movement from temperature change as fermentation, I wouldn't expect to see any signs of fermentation from S-04 for at least 8 hours, more likely 12 hours or more.Not 1 or 2 hours.
 
Thermowells are great, and not expensive.

I think you just put the yeast to sleep, and when they go to sleep they don't like to wake up, in my experience. But eventually they do, if you have good sanitation no harm no foul.

I had this happen several times, then got a thermowell, which solved the problem. My ferm chamber was overshooting and overcooling the beer, as I discovered when first using the thermowell. Now, I chill a few degrees below pitching temp (50' 1/2" wort chiller makes this easier), and no issues, plus super accurate measurements of the beer with a thermowell and temperature sensor while fermenting.
 
I think you may have mistaken air movement from temperature change as fermentation, I wouldn't expect to see any signs of fermentation from S-04 for at least 8 hours, more likely 12 hours or more.Not 1 or 2 hours.

I don't know.... the airlock was consistently bubbling (slowly) after about 2 or 3 hours. And also, it's dry yeast, doesn't dry yeast have a shorter lag phase?
Iv'e had home brews that started fermenting after 2 hours.
 
Unless you plan on having a typhoon in your ferm chamber, I doubt that air will mess with ferm temps enough to throw it off, especially if your probe fills the inner lumen.
 
I am using a temp controller. I ordered an stc-1000 from ebay and connected it to a fridge which is now my fermentation chamber. I brought the temp down to 65F and the airlock is still showing activity. It's just so weird what happened to me and I don't understand it. I was thinking maybe it was something else: I was shaking the bucket for a few minutes before pitching the yeast in order to oxidize the wort, so maybe the yeast was sitting on the foam that was created on top for a while until it settled and then the yeast started working? Does that make any sense?


Hopefully your shaking did not oxidize your wort which is undesirable. Oxygenation is what you want to achieve. Consider an O2 stone & O2 source.
Also ++1 on getting your wort to pitching temp first then pitching the yeast. You're fighting the exothermic action of the yeast when trying to cool to quickly after fermentation begins.
Set your controller at around 66°F and let your wort temp drop then pitch your yeast. After 3-4 days if you want to SLOWLY raise your temp a couple of degrees you can.
 
I'll be voice of dissent.

I was all set to buy thermowells till reading and discovering more.

Without a programmable thermostat like a BrewPi with inbuilt predictive algorithms placing the probe in a thermowell is demonstrably less accurate in controlling beer temps than the probe insulated and placed against the wall of the FV.

Like so

48 hours.jpg

Both are very effective and the difference in efficacy is in all likelihood negligible. One option comes with a cost the other does not.

No thermowell for me.

My method with fermentation temps.

Set temperatures should only ever rise, never fall, till the job is done, then crash to near freezing, fine and keg.
 
I don't mean to completely hi-jack this thread but I figured it would be better than making a similar thread to ask my question.

So I brewed a blonde last night and pitched it on a yeast cake of us-05 from my previous batch and put it in my swamp cooler. I guess I added too much ice because it dropped to 54° wort temp. Pretty sure I shocked the yeast But will I be able to rouse them again? Or will I need to pitch new yeast? I don't think any fermentation has even started.
 
I don't mean to completely hi-jack this thread but I figured it would be better than making a similar thread to ask my question.

So I brewed a blonde last night and pitched it on a yeast cake of us-05 from my previous batch and put it in my swamp cooler. I guess I added too much ice because it dropped to 54° wort temp. Pretty sure I shocked the yeast But will I be able to rouse them again? Or will I need to pitch new yeast? I don't think any fermentation has even started.

Just let the wort warm to fermentation temperature. I have often pitched the same yeast almost as low, 56°F. Fermentation activity would begin at around 61°F.
 
Just let the wort warm to fermentation temperature. I have often pitched the same yeast almost as low, 56°F. Fermentation activity would begin at around 61°F.

Ok awesome, that's what I hoped to hear. I just gave it a good shake to aerate it better, and the temp was right around 60, sadly I accidentally dropped my digital thermometer in the water >.>

Update:
As soon as I shaked it and it was around 60°f I went outside, smoked a cigarette and came back in to the bucket lid pushing up from the pressure and bubbles coming out the blow off tube. I'm amazed lol never had activity this quick.
 
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