Stalled fermentation

[Greynolds16]

Hey everyone,

I am running into an issue on my last two brews and I am wondering if anyone has any guidance.

I have recently made two beers that required getting the wort to lower temperatures than I normally do (I usually pitch at around 70F, as cool as it gets in my sink of ice and with my immersion chiller) and instead have been shooting for pitching at 65F or so. Both times I have run into the issue that fermentation just doesn't start.

My process is to aerate the wort by pouring and shaking, put it in the kegerator for a few hours to get it to 65F, and then pitch the yeast. I then store the fermenter in a cooler bag with frozen two liters to keep it at temp. I am finding that the frozen 2 liters make the bottom of the fermenter colder than the top, where my tilt hydrometer is giving me readings of temp and gravity.

Should I be aerating the wort again after chilling and then pitch? Do I need to let the yeast get started and then cool it down? Does fermenting at these cooler temps just take longer and I need to relax?

 

[mashinary]

Not sure what your setup is, but how do you know it's not fermenting? Are you gauging by airlock activity or something visible from a carboy?

 

[Knightshade]

I think it is better on the yeast, as well as less stressful to start lower and then go higher in temp than the other way around.

By starting high and going low, you’re likely to put the yeast to sleep.

Where is the 65 degrees in relation to the ideal temp range of the yeast that you’re using?

How are you aware of the temp variation between the upper and lower parts of your fermenter that you mention?

Are you using yeast nutrient?

 

[Greynolds16]

Not sure what your setup is, but how do you know it's not fermenting? Are you gauging by airlock activity or something visible from a carboy?

I don’t have any activity in the airlock and my tilt hydrometer is staying stable unfortunately.

 

[Greynolds16]

I think it is better on the yeast, as well as less stressful to start lower and then go higher in temp than the other way around.

By starting high and going low, you’re likely to put the yeast to sleep.

Where is the 65 degrees in relation to the ideal temp range of the yeast that you’re using?

How are you aware of the temp variation between the upper and lower parts of your fermenter that you mention?

Are you using yeast nutrient?

It’s a cal common yeast so it’s 58-68 target temp.
As far as the temp variation, when I shake the fermenter around the hydrometer reading drops by a few degrees.

 

[Knightshade]

It’s a cal common yeast so it’s 58-68 target temp.
As far as the temp variation, when I shake the fermenter around the hydrometer reading drops by a few degrees.

I know I've read somewhere that controlling fermentation temp can be one of the biggest "upgrades" in your beer product. I'm assume you're not doing your yeast any favors with the temp striations in your fermenter. Yeast stress leads to off flavors. Perhaps a mini fan in your cooler bag might help to achieve some consistent temps in the bag itself?

Regarding the stalled activity, I've never pitched additional yeast. I have found yeast energizer to help on occasion though.

Although..I just re-read your post...before posting this reply. It sounds like you've got fermentation that isn't even starting. Based on the title of stalled, I thought it was kicking off a little, then stopping. So after going through it again.

• My striation comment still stands.
• You shouldn't have to re-aerate the wort after removing it from your kegerator. I'll chill my wort down as much as possible...or I have the patience for with my IC, pump into my fermenter, then put that in my chamber, along with the yeast until it gets to pitching temp. Once that happens, I'll pitch and hook up all my blow off stuff.
• Within 24 hours, if not earlier..I'll expect to see some airlock activity. I have had to wait longer before, but this is before I started being fastidious about adding yeast nutrient in last 10-15 of boil.

 

[hotbeer]

I'd be a little concerned about how you might be keeping the fermenter chilled. If the frozen stuff you are putting in there is in contact with the fermenter, then likely the bottom layer of the fermenter is getting way to cold for the yeast.

Even with the ice blocks pulled away from it you might have a big difference in temp from top to bottom depending on what type of cooler bag you have it in.

Also how often you peek inside might affect it too leaving the top layer the tilt is in warmer than the rest.

Is this a bottom fermenting yeast or top fermenting yeast? I'm assuming bottom, but had to ask just to be sure the i's were dotted.

 

[Alex4mula]

It is an Ale. I also think the ice at the bottom is cooling maybe too much and stopping the yeast. I would try something to cool more evenly.