Spike Conical - Temperature Stratification

[ZeroMile]

A couple of months ago, I took the plunge and purchased a Spike CF10 conical to replace my buckets. I also purchased a bunch of accessories, including the temperature control coil. I have that rigged up to a cooler containing ice water and a pond pump to control fermentation temperatures. The temperature is controlled using an Inkbird ITC-308, the probe of which is placed in the CF10's thermowell.

The setup worked like a charm, or so I thought. On my current brew, I noticed during the first couple of days of active fermentation that although the temperature controller would read a steady 66 degrees, it would drop significantly to 61 or so when I would swirl the fermenter. This suggests to me that there is some significant temperature stratification within the fermenter. Now that active fermentation is mostly over, the temperatures are more stable but still drop a couple of degrees when I swirl the fermenter after the chiller has been running.

A couple more facts, to the extent they are relevant. I'm brewing a 5 gallon batch, so the fermenter contains about 6.5 gallons of beer. The CF10's thermowell is at the 5.5 gallon mark, which is towards the top of the beer. Also, Spike has not released their temperature control system, so there is no jacket around the fermenter. Ambient temp is around 70 degrees.

Anyone have any ideas about how to keep the temperature more consistent? Is this even something I should worry about? For what it's worth, I reached out to Spike who were very responsive but didn't really have any answers for me.

Thanks!

 

[brick_haus]

I have no answer either except to constantly circulate/agitate the fermenting beer, which is impractical.
I suggest that you adapt your process to account for your equipment's idiosyncrasies. The beer in close proximity to the coils will always be colder than the beer that is not.
Find a setting that gets you the results that you or your yeast like.

 

[bluemoon737]

Suggest when doing 5 gallon batches you swap the sampling port and thermowell so the thermowell is fully submerged in the beer. I believe Spike mentions this somewhere on their website and it is what I have done with mine. I just put my first brew in the CF10 this past weekend (after getting all my chilling parts in place) so there is still plenty "going on" but I will check down the road to see if I have the same issues.

I too can't wait until they get their jacket released!

 

[ZeroMile]

Suggest when doing 5 gallon batches you swap the sampling port and thermowell so the thermowell is fully submerged in the beer.

Yes, I think this will be the next thing I try.

 

[iijakii]

The jacket should help whenever it finally arrives. Anyway you could temporarily insulate it? Reflectix is cheap. Or a blanket lol.

 

[ZeroMile]

The jacket should help whenever it finally arrives. Anyway you could temporarily insulate it? Reflectix is cheap. Or a blanket lol.

Yeah, I may do that. If the beer is significantly colder around the coil, I'm not sure the insulation will help with stratification, right? But, the insulation would help in that the chilling coil wouldn't need to be used as often.

 

[iijakii]

Yeah, I may do that. If the beer is significantly colder around the coil, I'm not sure the insulation will help with stratification, right? But, the insulation would help in that the chilling coil wouldn't need to be used as often.

Cooling not kicking on as often means more time to balance out, no? Plus less heat transferred through the walls.

 

[bluemoon737]

Just agitated my CF10 quite a bit with no change in indicated temp on the inkbird controlling my cooling pump. As I stated, my temp probe is in the lower sampling port position.

 

[pennengr]

I'm on my third batch on the CF10, and have tried both ports. I'm getting much better performance on the lower port as well - running about 6.5 gallon batches. I just bought a blank for the top port.

 

[ZeroMile]

Sounds like moving the thermowell is the ticket. Thanks all!

 

[sheikyerbouti]

Do you use anything to hold the sensor in the thermowell? I just ordered the conical and I'm trying to figure out all the best practices

 

[homebrewdude76]

In have the same question, currently I am just pushing the probe into the spike thermowell. No clue what type of contact I have. I would prefer some other SS direct contact option. Not sure it exists.

 

[pocketmon]

I use my CF10 to brew 5gal batch and moved the thermowell to sample port.

Since I have an iSpindel with BrewPiLess setup, I can monitor the temperature reading from iSpindel and that at the thermowell.
During active fermentation, the difference is very small, within the error of the sensors. (Even outside the ferment, place them at the same place, the readings do not agree to each other.) I believe that the co2 bubbles during active fermentation prompt the recirculation of wort. One of the evidence is big difference between two readings during cold crash.

 

[pennengr]

I have my thermowell in the lower port as well. I threaded in a male camlock, and drilled a hole in a rubber camlock dust cap to secure the thermocouple in the well. The rubber does a good job of gripping the wire and keeping the thermocouple from sliding out.

 

[pennengr]

This one: https://www.brewhardware.com/product_p/camvinyl.htm

 

[homebrewdude76]

I have my thermowell in the lower port as well. I threaded in a male camlock, and drilled a hole in a rubber camlock dust cap to secure the thermocouple in the well. The rubber does a good job of gripping the wire and keeping the thermocouple from sliding out.

The flexible inkbird sensor is just pushed in the well? And your camlock holds it in place?

 

[pennengr]

The flexible inkbird sensor is just pushed in the well? And your camlock holds it in place?

I’m using a BrewPi Spark probe, but it should be basically the same. I just drilled a tight hole in the thin part of the camlock dust cap, squeezed my probe through, and pushed the cap onto the camlock, which is screwed into the NPT on the well. It stays put reasonably well.

 

[pennengr]

Here's a quick photo:
View media item 68718

 

[bluemoon737]

In have the same question, currently I am just pushing the probe into the spike thermowell. No clue what type of contact I have. I would prefer some other SS direct contact option. Not sure it exists.

Never had an issue with the probe falling out with just pushing it all the way in. If it makes you feel better you could tightly wrap some aluminum foil around the probe to increase the friction fit.

 

[sheikyerbouti]

Thanks folks!

 

[pocketmon]

Cable Gland should be a solution.
https://www.ebay.com/sch/i.html?_nkw=cable+gland+npt

A 1/2-1/4 busing and 1/4 NPT cable gland might do the job, given the cable of thermometer is usually small.

 

[dlink72]

Something I noticed about mine and you may want to consider as well. When I first used mine I had the cold glycol hooked up to the coil the wrong way. The glycol was going straight to the bottom of the coil and circulating up and back to the chiller. That created a cold spot at the bottom of the fermenter that was evident by a condensation ring. I swapped ports so that the glycol circulates from the top down. That seemed to help and I’m guessing causes the wort to slightly circulate because the condensation ring was no longer there. I hope that makes sense.