Raging! Then the party was over. :(

I got my new Johnson Temperature Control. Got my new chest freeze (Costco rules). Did a 24 yeast starter, got it rollin' and the damn thing nearly blew up the yeast was partying so hard. Thank goodness for blowoff tubes. I nearly needed a gas mask to duck my head in the chest. The alcohol fumes were so strong, it made my eyes water.

Anyway, after a perfect 10-12 hours at 68° in the chest, my overnight dropped considerably. Woke up and it was 64° with FAR less activity. Maybe because the heat from the yeast activity "chilled out."

Did I kill my yeast with it just dropping 4°, or did so much work get done day one, it's mellowed out and started a normal chug?

I've been tweaking my Johnson (hehe) to get it right. So many people say set them at 65 for a 68° temp, but mine seems to work the opposite. I guess my chest, being brand new, chills super-fast. And with great effect.

I'm playing it safe right now and just locked it in at 68°. Seems to be doing the job (for now).

DID I KILL MY YEAST??

Help a newbie out, please, with all of your brew wisdow.

Brad

Was the temperature controller measuring the inside air temperature or did you tape the temp probe to the side of the carboy?

What kind of yeast? What kind of beer? What day of fermentation are you on?

All of these are questions that need to be answered before you will get the answers you're looking for.

If it's just a run of the mill california ale yeast like WLP001 then 64 is a tad on the low side, but not enough that would make me worry.

If you're a few days in, you're going to see a significant drop off in activity, but that doesn't means it's finished or even close to finishing. It CAN be a good indicator, but a really unreliable one at best. Let it ferment for at least a week and then start poking around and thinking about gravities.

Your wort can get 5-10 degrees warmer than the ambient temperature in you chest freezer. If you where going by ambient, my guess would be that the beer fermented out quickly at the higher temperature.

Side of the carboy. I even have a light foam wrap on probe. I did my research. Air is much thinner than liquid. A very lightweight, breathable foam simulates carboy interior temps very well. I just don't want dead yeast. Especially considering I brewed this batch late at night, half drunk, which made quite the mess, and everything feel SO heavy when you're drunk. It was the boil from hell.

A four degree drop isn't a problem. Sure avoid temperature swings if at all possible, but temps will rise during primary fermentation and then drop again once it slows. I routinely see a 2-4 degree jump. I try to control it by starting the pitch temp a few degrees where I want it (pitch at 60F to ferment around 62-64F) then I raise the temp a few degrees as fermentation slows.

Also those fumes in your chest freezer are CO2 coming from your airlock/blow tube, not alcohol.

619Brewer said:

What kind of yeast? What kind of beer? What day of fermentation are you on?



All of these are questions that need to be answered before you will get the answers you're looking for.



If it's just a run of the mill california ale yeast like WLP001 then 64 is a tad on the low side, but not enough that would make me worry.



If you're a few days in, you're going to see a significant drop off in activity, but that doesn't means it's finished or even close to finishing. It CAN be a good indicator, but a really unreliable one at best. Let it ferment for at least a week and then start poking around and thinking about gravities.

Click to expand...

Today will be day 3, but really 2.5 at this point. White Labs WLP 002/24 hr. start, IPA.

IMHO you should dump it

dobe12 said:

A four degree drop isn't a problem. Sure avoid temperature swings if at all possible, but temps will rise during primary fermentation and then drop again once it slows. I routinely see a 2-4 degree jump. I try to control it by starting the pitch temp a few degrees where I want it (pitch at 60F to ferment around 62-64F) then I raise the temp a few degrees as fermentation slows.



Also those fumes in your chest freezer are CO2 coming from your airlock/blow tube, not alcohol.

Click to expand...

That was some intoxicating CO2 fume, and not in a stinky way.

poptarts said:

IMHO you should dump it

Click to expand...

Based on what? Science, or trolling?

dobe12 said:

A four degree drop isn't a problem. Sure avoid temperature swings if at all possible, but temps will rise during primary fermentation and then drop again once it slows. I routinely see a 2-4 degree jump. I try to control it by starting the pitch temp a few degrees where I want it (pitch at 60F to ferment around 62-64F) then I raise the temp a few degrees as fermentation slows.



Also those fumes in your chest freezer are CO2 coming from your airlock/blow tube, not alcohol.

Click to expand...

So, if I'm understanding, which would make perfect since .... Adjust Temp Control by a couple of degrees cooler at start of fermentation, then adjust up slowly as it calms down? If that's what you're saying, it makes good sense to me.

JustLooking said:

Your wort can get 5-10 degrees warmer than the ambient temperature in you chest freezer. If you where going by ambient, my guess would be that the beer fermented out quickly at the higher temperature.

Click to expand...

But the fermometer read 68° the ENTIRE time, which, to my knowledge, is a perfect fermentation temp. Are you saying it's a bad thing, or not? Not understanding your response.

68F is on the high side for ale fermentations so they WILL PARTY HARD for the first 24-48 hours. I always ferment my ales at 65F and they are highly active with high krausen for 2-3 days and then the krausen is just gone within 12 hours and no more churning. Yours sounds completely normal. I check my fermenters every few hours for the first few days and the hour I realize they are starting to slow down I start increasing the temp control by 1 degree every 8 hours and this usually prevents the 2-4 degree temp drop as fermentation slows.

You are making beer, no need to rush! Sit back and let the yeast work for another couple weeks!

typebrad said:

So, if I'm understanding, which would make perfect since .... Adjust Temp Control by a couple of degrees cooler at start of fermentation, then adjust up slowly as it calms down? If that's what you're saying, it makes good sense to me.

Click to expand...

Exactly! If I want to ferment an APA for example, I like to ferment in the low 60's for a clean profile. I'll cool to 60F and pitch. I keep my controller set to 64-65F (it runs cold, so I know the internal temp is about 5F cooler). I hold at 60F for the first few days knowing that the fermenting wort/beer is actually going to climb a few degrees to around 62-64F. Somewhere around day 3, I start checking the fermentors temp. When it starts to drop down a little I start raising the temp on the controller a few degrees. This enables me to pitch and hold at a cool consistent temp throughout fermentation and raise it at the end to help the yeast finish up.

Also, fermentation temperature is only important for the first few days, maybe 3-5 days. After that raising the temp will help the yeast finish up, but most/all of the flavor contributed by the yeast will already be there. This is why after 5-7 days or so I just pull the fermentor from my fridge and let it sit at room temp, which is around 70F in my house.

typebrad said:

But the fermometer read 68° the ENTIRE time, which, to my knowledge, is a perfect fermentation temp. Are you saying it's a bad thing, or not? Not understanding your response.

Click to expand...

If the controller's set point was set at 68° and the differential was set at 2°, then the cooler will kick on when the temp reaches 70° and will stop cooling once the carboy reaches 66°. So no, it didn't stay 68° the entire time.

LandoLincoln said:

If the controller's set point was set at 68° and the differential was set at 2°, then the cooler will kick on when the temp reaches 70° and will stop cooling once the carboy reaches 66°. So no, it didn't stay 68° the entire time.

Click to expand...

The temp in the cooler has a differential of 4 degrees but a 5+ gallon volume of beer in the fermenter will buffer that temp swing and keep the beer temp within less than 1 degree change.

Jayhem said:

The temp in the cooler has a differential of 4 degrees but a 5+ gallon volume of beer in the fermenter will buffer that temp swing and keep the beer temp within less than 1 degree change.

Click to expand...

+1. 5 gallons of beer won't warm up fast. The fridge will warm and cool 2-3 degrees over and over again before the beer ever moves up or down a degree.

Jayhem said:

The temp in the cooler has a differential of 4 degrees but a 5+ gallon volume of beer in the fermenter will buffer that temp swing and keep the beer temp within less than 1 degree change.

Click to expand...

Not if the temp probe is reading the beer temp. Which it is in this case.

LandoLincoln said:

Not if the temp probe is reading the beer temp. Which it is in this case.

Click to expand...

Not really. It was in a foam wrap outside the fermentor. I seriously doubt those conditions will mimic 5 gallons of fermenting work exactly.

dobe12 said:

Not really. It was in a foam wrap outside the fermentor. I seriously doubt those conditions will mimic 5 gallons of fermenting work exactly.

Click to expand...

Within a degree, maybe 1.5 degrees? Yes.

LandoLincoln said:

Within a degree, maybe 1.5 degrees? Yes.

Click to expand...

Doubt it.

A temp probe inside of a small piece of foam is going to fluctuate with rising temperatures much faster than 5 gallons of a dense sugary wort, IMO.

In the end we're arguing over 1-2 degrees. This is silly.

Pitch cooler and set your temp gauge a few degrees cooler than where you want to ferment. Fermentation will start, temps will rise, and your fermentation will be right where you want it to be. With a little tinkering, you'll get your system figured out. It's not hard.

Thanks for the votes of confidence, everyone. If a single degree, or two, was the difference between successful homebrew and not, we would all be drinking Coors.


Sent from my iPhone using Home Brew

to add a data point-

I ran a test where I had one probe in a stainless thermowell immersed halfway down into the beer and another attached to the side with foam insulation.

I had these connected to a data acquisition unit.

both probes were negligibly different from each other. nor did they differentiate from the stick-on thermometer.

And I've only got one probe. What do I do with 3 primary? lol


Sent from my iPhone using Home Brew

typebrad said:

Thanks for the votes of confidence, everyone. If a single degree, or two, was the difference between successful homebrew and not, we would all be drinking Coors.

Sent from my iPhone using Home Brew

Click to expand...

It's not a difference of a single degree, or two. If your temp differential was set to 2°, then you had temp swings of four degrees. Your beer temp was swinging between 66° and 70°, which is a bit warm for this yeast, but not crazy warm. Personally, I think you should have set the controller for 65° instead of 68°. There's no fine line between "successful" homebrew and "unsuccessful" homebrew. You're just going to get more fruity esters from the higher temps. You might prefer this, so it might be an improvement.

WLP002 is a highly flocculent yeast. It seems to me that the highly flocculent yeast do their thing quickly and then poop out, whereas the less flocculent yeast strains are more steadily active for longer periods. Your yeasts definitely didn't get killed or went to sleep by the cooler temps.

typebrad said:

And I've only got one probe. What do I do with 3 primary? lol

Sent from my iPhone using Home Brew

Click to expand...

If you have three beers fermenting and you only have one probe...

Fermentation temps are most critical during the first few days of fermentation, less so afterwards. So if you have a beer that you just pitched yeast into and two beers that are closer to the end of the fermentation period, then definitely put the probe on the freshly-pitched fermentor.

But let's say you have two beers that were both pitched within 24 hours of each other, and one works best around 62-68° range and the other works best around 66-74°. I'd set the probe on the cooler one and set the controller to 65°, and keep an eye on both temps. I find that it's better to ferment cool than warm.