Chest Freezer for Fermentation

[sbooker]

I am purchasing a new Chest freezer 8.7-cu. Thinking about getting an Inkbird ITC-308 for temp controller. Great price compared to one of the most common ones purchased out there.

Have searched the forum looking for the below answers.

1. What temp do I set the actual freezer at? Max, low ????

2. Concerned with the compressor coming on and off. Have read that you can burn one up pretty quick because of it cycling too often.

3. I somewhat understand about setting the controller to have around a 3-4 degree swing.

Any advice would be appreciated. As this will be a pretty costly investment

Thanks,
Stephen

 

[CA_Mouse]

I have mine set to the coldest setting and my temp controller is set to my desired temperature. I think the compressor runs about 15 minutes ever hour or two (never actually sat there and timed it). Of course I'm not using my chest freezer for fermentation, I have a custom built chamber using an InkBird with a 5,000 BTU Air Conditioner. My chest freezer is a Keezer and is kept much cooler than it would be for fermentation.

 

[JONNYROTTEN]

Theres a setting on the inkbird that stops the compressor from coming on to often.I set it to the highest level.I think its 10 minutes,maybe 15.Curios if the low/max setting matters.I would think that the inkbird overrides that? If compressors were burning up nobody would use chest freezers.I wouldn't sweat it.

 

[Bighokie]

I have that same setup, with the ink bird and 7cf freezer. I keep it about as cold as it'll go and the thermo set to +\- 1 degree. I've used it for a year with no probs. I also put a heating pad in there for the heat side. Put the thermo probe in a bottle of water to maintain similar medium as the beer, next to your carboy. Good luck!

 

[JONNYROTTEN]

I have that same setup, with the ink bird and 7cf freezer. I keep it about as cold as it'll go and the thermo set to +\- 1 degree. I've used it for a year with no probs. I also put a heating pad in there for the heat side. Put the thermo probe in a bottle of water to maintain similar medium as the beer, next to your carboy. Good luck!

This is wrong info.The probe should be attached the primary or in a thermowell to monitor the temp of the fermenting beer that rises as it is fementing.A glass of water is just measuring the air temp

 

[Bighokie]

Interesting, do you just put it in thru the stopper? I was concerned with sanitation and having plastic/metal in the fermenter

 

[sbooker]

Any thoughts on duck taping the sensor to the side of the carboy? Since I don't have a thermowell. Will it be better than just having it in the freezer collecting ambient temp?

 

[Rcbandl]

Interesting, do you just put it in thru the stopper? I was concerned with sanitation and having plastic/metal in the fermenter

I take a washcloth, put it in a zip lock baggie and use a bungie cord to hold it to the side of the carboy. Then just slide the probe between the baggie and carboy

 

[day_trippr]

I recommend a more substantial insulator than wadded paper towels or wash cloths.
Rejection of ambient temperature is at least as important as thermal coupling to the fermentor.

I use a 4" square of inch thick closed cell foam commonly found in consumer product packaging. Excellent performance...

Cheers!

 

[Yeastieboy]

You can pick up a 12" Duda stainless thermowell on Amazon for $12 bucks. Has worked great for me.

 

[WarmGas]

I have this setup with an STC 1000 which works great. I keep the setting as others have said, at max cold. There is very little cycling as chest freezers are insulated.

I am not paranoid about getting the last 10th of a degree of temperature measurement in my wort for the following reasons:

1) I have several fermentation vessels in there and I just want to keep them all happy at 18 degrees C.

2) I have taped the temp probe to the side of one fv and there was almost no discrepancy between that and the air temp inside the chest freezer.

3) No matter how fancy you want to make your probe you can still only measure the skin temp on the outside of your fv - you are not measuring the wort temp, especially the temp in the middle of the wort. So you can only do so much without a built-in probe that reaches to the middle of the wort.

Well, that's my thinking on it right now.

Good luck.

 

[JONNYROTTEN]

3) No matter how fancy you want to make your probe you can still only measure the skin temp on the outside of your fv - you are not measuring the wort temp, especially the temp in the middle of the wort. So you can only do so much without a built-in probe that reaches to the middle of the wort.


Good luck.[/QUOTE]
That's whats nice about a thermowell.For all the work,time and money Ive already put into my system and brew day another $12 to measure the inside of the bucket and actual wort temp seems like money well spent.
Also about the compressor,I run mine in the basement and the light bulb comes on more then the compressor.If it cost $10 a year in electric its probably a lot..Heres the themowell
https://www.brewershardware.com/12-Stainless-Steel-Thermowell-TWS12.html

 

[troglodytes]

That's whats nice about a thermowell.For all the work,time and money Ive already put into my system and brew day another $12 to measure the inside of the bucket and actual wort temp seems like money well spent.
Also about the compressor,I run mine in the basement and the light bulb comes on more then the compressor.If it cost $10 a year in electric its probably a lot..Heres the themowell
https://www.brewershardware.com/12-Stainless-Steel-Thermowell-TWS12.html

You haven't had any issue with huge temp swings due to the thermowell? I had to stop using it because by the time the middle of the carboy was at the correct temp the ambient temp of the freezer would be so high or low it would drive the temp off by 2 to 3 degrees in either direction which was enough to stall out certain yeasts. With insulation and taping to the side I found out that the freezer would do shorter cycle with smaller swing.

 

[Natdavis777]

When in use, I keep the probe secured to the carboy under several layers of bubble wrap, secured with a bungee cord. Temp is set to desired ferm temp. When not in use (which may be a day or two, when the probe if free hanging, I set it to the 70s so the compressor doesnt kick on at all. On brew day, I set the temp back down to the mid 60sF, and by the time the carboys hit the chamber, the ambient temp of the cooler and the temp of the beer are very close. Once the probe on the side reads my pitching temp (within an hour or two during summer months) I pitch the yeast.

I found out the hard way on my first chamber about just monitoring ambient temps. I burnt the compressor up within a year. So far, my last chamber is coming up on a year and still kicking strong.

 

[JONNYROTTEN]

You haven't had any issue with huge temp swings due to the thermowell? I had to stop using it because by the time the middle of the carboy was at the correct temp the ambient temp of the freezer would be so high or low it would drive the temp off by 2 to 3 degrees in either direction which was enough to stall out certain yeasts. With insulation and taping to the side I found out that the freezer would do shorter cycle with smaller swing.

I haven't had any issues.Its in my basement so I'm not staring at it all day either.My routine is to put around 160 deg bucket in the freezer.Leave probe hanging set at pitch temp overnight.The next day I'm at correct pitch temp and put the probe in the themowell.I have it set to a 1 deg differential so when the freezer/light comes on it only adjusting the temp by 1 deg.

 

[sbooker]

Thanks for all the great info!!!!!! Freezer bought, Inkbird ordered.

 

[Natdavis777]

I may be in the market for a second ferm chamber... May get the inkbird 308 instead of building one.

 

[doug293cz]

You haven't had any issue with huge temp swings due to the thermowell? I had to stop using it because by the time the middle of the carboy was at the correct temp the ambient temp of the freezer would be so high or low it would drive the temp off by 2 to 3 degrees in either direction which was enough to stall out certain yeasts. With insulation and taping to the side I found out that the freezer would do shorter cycle with smaller swing.

This is exactly why taping the probe on the side of the fermenter is a better choice than a thermowell, when using a simple on off controller like an STC-1000 or ITC-308.

The best control can be obtained with an intelligent controller, like a brewpi, that uses a probe in a thermowell in conjunction with a probe in the chamber ambient. This allows prevention of severe over/under shoot of the ambient vs. beer.

Brew on

 

[JONNYROTTEN]

This is exactly why taping the probe on the side of the fermenter is a better choice than a thermowell, when using a simple on off controller like an STC-1000 or ITC-308.

The best control can be obtained with an intelligent controller, like a brewpi, that uses a probe in a thermowell in conjunction with a probe in the chamber ambient. This allows prevention of severe over/under shoot of the ambient vs. beer.

Brew on

To each there own.I tried the tape method and didn't like it. If taping is better why does EVERYONE insulate the crap out of the probe on the bucket to block any chance of an ambient temp reading.What there doing is trying to get the temp of the inside of the bucket which is exactly were the themowell is.
The only time I ever had an issue was the very first time I used the freezer and put the probe in the 160 deg wort and set inkbird to 65.The fridge over shot down to the 20's. And that was when it was taped to the bucket.Ive noticed on all brews that the temp rises at a VERY slow rate inside the bucket.Its not like its jumping up 5 deg instantly and the freezer needs to run forever to compensate. Its only rising/dropping 1 deg.And that doesn't overshoot ambient temps enough to matter

 

[doug293cz]

To each there own.I tried the tape method and didn't like it. If taping is better why does EVERYONE insulate the crap out of the probe on the bucket to block any chance of an ambient temp reading.What there doing is trying to get the temp of the inside of the bucket which is exactly were the themowell is.
The only time I ever had an issue was the very first time I used the freezer and put the probe in the 160 deg wort and set inkbird to 65.The fridge over shot down to the 20's. And that was when it was taped to the bucket.Ive noticed on all brews that the temp rises at a VERY slow rate inside the bucket.Its not like its jumping up 5 deg instantly and the freezer needs to run forever to compensate. Its only rising/dropping 1 deg.And that doesn't overshoot ambient temps enough to matter

I did fail to mention that when taping/strapping a temp probe to the side of the fermenter that some insulation is optimal. But, you don't want perfect insulation, as that gives you the same situation as a thermowell, as far as over/under shooting the chamber temp. What you're looking for is about an 80/20 split of beer temp vs. chamber temp driving the probe, as this shuts down heating/cooling before over/under shoot gets out of hand. Chamber over/undershoot drives a higher amplitude temperature fluctuation in the beer, which is what you are trying to limit.

If you are familiar at all with control theory, you know that long time lags between control inputs and process response leads to excessive oscillation around the set point. And this is exactly the situation in most freezer based fermentation chambers. The chamber temp can be raised or lowered much faster than the beer temp, and oscillations ensue.

If you are comfortable with the level of temp oscillation you get in your fermenter using a thermowell, then by all means continue to use that method. But, you shouldn't be telling people that is the optimal way to minimize oscillations when using a simple on-off controller.

Brew on

 

[dttk0009]

I did fail to mention that when taping/strapping a temp probe to the side of the fermenter that some insulation is optimal.

Any tips on what would work nicely? I've just got a chest freezer with an inkbird coming as well, and I also plan on taping the probe to the side of the bucket, but was just planning on using a few layers of tape.

 

[doug293cz]

Any tips on what would work nicely? I've just got a chest freezer with an inkbird coming as well, and I also plan on taping the probe to the side of the bucket, but was just planning on using a few layers of tape.

A few layers of tape is probably not enough. You want something with some insulating value. A 4" x 4" x 1/2" to 1" thick piece of closed cell foam (packaging padding), a dry sponge, a few layers of bubble wrap, etc. seem to work well for a lot of brewers. It hasn't been reduced to an exact science (to my knowledge.)

Brew on

 

[RedlegEd]

Hi. If you read through this post, there's obviously a difference of opinion what works best. For my part, I've used both methods successfully, however, I found the combination of this thermowell, and the Inkbird ITC-1000/STC-1000+ works best for me. The temp probe fits cleanly down to the bottom of the tube. The trick is not to put the thermowell in the center of the lid, but just in about 2-3" from the edge. While not as accurate as a PID type control that measures both ambient and fermentor temps, it seems to do a pretty good job of preventing wild swings (oscillation) in fermentor temps. If you decide to tape it to the side, I'd suggest using bubble wrap or some other form of insulation between the tape/bungee and the probe against the FV wall. As doug293cz pointed out, you want some influence of the ambient temperature, but most of the influence should be from the FV.

 

[JONNYROTTEN]

I did fail to mention that when taping/strapping a temp probe to the side of the fermenter that some insulation is optimal. But, you don't want perfect insulation, as that gives you the same situation as a thermowell, as far as over/under shooting the chamber temp. What you're looking for is about an 80/20 split of beer temp vs. chamber temp driving the probe, as this shuts down heating/cooling before over/under shoot gets out of hand. Chamber over/undershoot drives a higher amplitude temperature fluctuation in the beer, which is what you are trying to limit.

If you are familiar at all with control theory, you know that long time lags between control inputs and process response leads to excessive oscillation around the set point. And this is exactly the situation in most freezer based fermentation chambers. The chamber temp can be raised or lowered much faster than the beer temp, and oscillations ensue.

If you are comfortable with the level of temp oscillation you get in your fermenter using a thermowell, then by all means continue to use that method. But, you shouldn't be telling people that is the optimal way to minimize oscillations when using a simple on-off controller.

Brew on

I've never once seen the controller go below or above 1 deg from where I've had it set.Being that the themowell is in the wort giving exact Liquid temps nothing is being over shot up or down.If the ambient temps were overshooting and holding those off temps for long enough to raise or lower the temp by over a deg I would have noticed at least once.Again to each there own.I got sick off taping/bungie cord/strap the probe to the bucket and finagling it into the chamber.For me,the themowell has worked more then perfect and are easy,neat and clean.Most importantly I know exactly what the ferm temps are inside the bucket.Its a piece of mind for me.Its all good do whatever works for you

 

[sbooker]

Once I get my wort down to pitching temp should i add it to fermenting chamber with yeast and then set desired temp, say 65 +/- 1 degree ?
OR
Get wort to 65 and then pitch yeast? I can usually get it down to around 70-72 with wort chiller on avg. So not sure when I should pitch?

 

[Yeastieboy]

I have gotten into the habit of brewing on Friday nights. I am typically pumping into the fermenter around 10:30PM. I aerate and put the fermenter into my fermenting fridge alongside the yeast starter. Then I pitch yeast the following morning.

 

[doug293cz]

Once I get my wort down to pitching temp should i add it to fermenting chamber with yeast and then set desired temp, say 65 +/- 1 degree ?
OR
Get wort to 65 and then pitch yeast? I can usually get it down to around 70-72 with wort chiller on avg. So not sure when I should pitch?

Most brewers recommend getting down to at least your target fermentation temperature prior to pitching. If you don't have the wort down to target temp, and the fermentation takes off quickly, then it takes longer to get the beer down to temp. This could cause some off flavors due to the higher initial temps. However, if fermentation doesn't kick off right away, then probably nothing bad happens. Getting the temp correct before pitching is cheap insurance.

I have gotten into the habit of brewing on Friday nights. I am typically pumping into the fermenter around 10:30PM. I aerate and put the fermenter into my fermenting fridge alongside the yeast starter. Then I pitch yeast the following morning.

I'm starting to like this method more and more. I can use a little less cooling water, and get the brew day finished a little earlier.

Brew on

 

[dttk0009]

I have gotten into the habit of brewing on Friday nights. I am typically pumping into the fermenter around 10:30PM. I aerate and put the fermenter into my fermenting fridge alongside the yeast starter. Then I pitch yeast the following morning.

That sounds pretty nice, but wouldn't that increase the risk of infection? Maybe I'm just paranoid, but as soon as I start cooling the wort I try to act swiftly to get the yeast in there and the bucket sealed (while making sure all the temps are on).

I'm actually fermenting my first lager right now. Pitched with the wort at 18 and the yeast at 20, then drove the temps down to 9.5C, which it hit at a fairly modest speed. After 30 hours the airlock started bubbling, which it has been since (at day 5 now).

What are the side effects of doing it this way?

 

[Yeastieboy]

That sounds pretty nice, but wouldn't that increase the risk of infection? Maybe I'm just paranoid, but as soon as I start cooling the wort I try to act swiftly to get the yeast in there and the bucket sealed (while making sure all the temps are on).

I'm actually fermenting my first lager right now. Pitched with the wort at 18 and the yeast at 20, then drove the temps down to 9.5C, which it hit at a fairly modest speed. After 30 hours the airlock started bubbling, which it has been since (at day 5 now).

What are the side effects of doing it this way?

I am pretty meticulous about sanitation. I personally believe that increased risk of infection, if any at all, is extremely low using this method. I've probably cooled several dozen batches over night before pitching without issue. It's so much easier. Plus, when the starter is spinning on the stir plate in the same fermenting fridge that I cool wort in, they are at the exact same temp when pitching. The yeast typically go nuts with 8 hours, as it seems to be a much easier transition for them.

 

[Natdavis777]

In summer months, I've only been able to get down to low 70s, so I'll have to wait until the next day sometimes to pitch the yeast (I pitch at fermentation temp, so usually mid to low 60s). Yet
to have an infection in scores of brews.

 

[dttk0009]

I'll give it a shot for my next batch then.