Freezer chamber temp fluctuation??

[danny3460]

Hello I am a beginner homebrewer from South Korea.
I was thinking of upgrading my swamp cooler to a freezer chamber for my fermentation.
My concerns are temperature fluctuation. The highest temp my freezer goes to is -17C or 2F which is PRETTY low.
I'm worried that this might cause the wort to
1. Be too cold(below suggested temp range) on the outsides while the inner part of the wort is still relatively warm.
2. I think this might cause high fluctuation in temperature even with temp control because temp probe inside the thermowell would read the insides of the wort
Would a fridge work better? The higher temps would soften out the temp fluctuation I think..
What are your thoughts?
Thank you

 

[mac_1103]

2F is too cold for fermentation period. You need an external temperature controller so that your freezer (or refrigerator) will maintain a temperature within the optimal range for the yeast. I think these are available in South Korea, but shipping might be prohibitive.

 

[day_trippr]

I suspect the OP is simply concerned the "cold ramp" induced by a freezer might be problematic for fermentation. Usually, it isn't a problem. Lots of folks have successfully used freezers for fermentation chambers - with add-on controllers, of course. If the allowed temperature differential is small enough (eg: 2°F) there really isn't going to be a pronounced "ramp" that could shock wee beastie yeasties

So I would encourage the OP to go with whichever makes them comfortable, freezer or fridge. They both work for fermentation...

Cheers!

 

[danny3460]

2F is too cold for fermentation period. You need an external temperature controller so that your freezer (or refrigerator) will maintain a temperature within the optimal range for the yeast. I think these are available in South Korea, but shipping might be prohibitive.

I will be using a temp controller for the freezer but I'm worried that 2F might be too stressful to the fermentation

 

[danny3460]

I suspect the OP is simply concerned the "cold ramp" induced by a freezer might be problematic for fermentation. Usually, it isn't a problem. Lots of folks have successfully used freezers for fermentation chambers - with add-on controllers, of course. If the allowed temperature differential is small enough (eg: 2°F) there really isn't going to be a pronounced "ramp" that could shock wee beastie yeasties

So I would encourage the OP to go with whichever makes them comfortable, freezer or fridge. They both work for fermentation...

Cheers!

Thank you for the info. I wanted to find something that compares two situations where one is temp controlled with something like 2f temperature and one with 30f ish temperature. But couldn't find one so I was worried it will cause negative effects for my yeasts.
I guess I'm going for the freezer then. Thanks!!

 

[day_trippr]

What will you be using for fermentation vessels? For best performance, tight coupling between fermenting wort and temperature sensor is important, as is isolation of said sensor from the ambient air temperature. A "thermowell" dropped into the middle of a fermentation vessel and containing the temperature sensor is often the optimal solution, but if you are using glass or plastic vessels, strapping the sensor to the side of the vessel with a thick pad of insulating foam works quite well, and is what I do with my 6.5 gallon Italian carboys.

Cheers!

 

[IslandLizard]

I will be using a temp controller for the freezer but I'm worried that 2F might be too stressful to the fermentation

I wanted to find something that compares two situations where one is temp controlled with something like 2f temperature and one with 30f ish temperature. But couldn't find one so I was worried it will cause negative effects for my yeasts.
I guess I'm going for the freezer then. Thanks!!

No-one ferments at 30°F (-1.1°C) or 2°F (-16.7°C). That would be much too cold for any yeast to ferment.

Those controllers have a set temperature. That's your target fermentation temp, say for example, 60°F.

The 2°F points to how far the temp is allowed to deviate from that set temp. For example, when set to 2°F the freezer will be turned back on when the temp rises above 60+2=62F, or turned off when it reaches 60-2=58F.

In post #6 (above) @day_trippr laid out how and where to mount the temp sensor to control the temp of your batch of beer or wine (the liquid) as closely to your set temp as possible.

 

[danny3460]

No-one ferments at 30°F (-1.1°C) or 2°F (-16.7°C). That would be much too cold for any yeast to ferment.

Those controllers have a set temperature. That's your target fermentation temp, say for example, 60°F.

The 2°F points to how far the temp is allowed to deviate from that set temp. For example, when set to 2°F the freezer will be turned back on when the temp rises above 60+2=62F, or turned off when it reaches 60-2=58F.

In post #6 (above) @day_trippr laid out how where to mount the temp sensor to control the temp of your batch of beer or wine (the liquid) as closely to your set temp as possible.

Thank you for the reply. I think my post can cause some confusion due to my English skills
What I meant is not fermenting at 2f but rather my freezer's highest temp setting is 2F.
And my concern is that at that FREEZING temperature outside parts of the ferm vessel would be exposed to WAY too low temps and that I thought would cause some trouble?

 

[IslandLizard]

And my concern is that at that FREEZING temperature outside parts of the ferm vessel would be exposed to WAY too low temps and that I thought would cause some trouble?

No, not really, the freezer will be shut off by your add-on controller before it gets anywhere near those extreme low temps. The location/placement of the sensor (probe) that comes with your controller is important in that.

You could use a small (computer type) fan to recirculate the air inside the freezer somewhat while the freezer is in her "on-cycle," but is usually not necessary.

What kind of freezer are you planning to use, a chest freezer or an upright? Many modern upright freezers have a built-in fan.

 

[danny3460]

No, not really, the freezer will be shut off by your add-on controller before it gets anywhere near those extreme low temps. The location/placement of the sensor (probe) that comes with your controller is important in that.

You could use a small (computer type) fan to recirculate the air inside the freezer somewhat while the freezer is in her "on-cycle," but is usually not necessary.

What kind of freezer are you planning to use, a chest freezer or an upright? Many modern upright freezers have a built-in fan.

I'm thinking of using a chest freezer because it was pretty hard to find one that fits my fermzilla.
I think I will go for the chest freezer chamber setting. Pretty relieved after hearing everyone about my concerns.
Thank you for the comments! Cheers!

 

[MaxStout]

Thank you for the reply. I think my post can cause some confusion due to my English skills
What I meant is not fermenting at 2f but rather my freezer's highest temp setting is 2F.
And my concern is that at that FREEZING temperature outside parts of the ferm vessel would be exposed to WAY too low temps and that I thought would cause some trouble?

You need a heating device to maintain temperatures above the freezer's range. You can use a seedling heating mat, a ceramic terrarium heater, etc.

Your temp controller should be 2 stage, meaning it will turn on the freezer when it needs to cool, and turn on the heating device when the temp needs to be raised. It will alternate back and forth between the two stages as the temp goes up and down.

For example, suppose you set the controller for 18C, with a plus/minus range of 2C. When the temp rises to 20C, it turns on the freezer until the temp drops to 18C, then it shuts off the freezer. And when the temp drops to 16C, it turns on the heating device until it warms to 18C.

 

[day_trippr]

I was literally typing similar thoughts when ^that^ was posted

Cheers!

 

[danny3460]

You need a heating device to maintain temperatures above the freezer's range. You can use a seedling heating mat, a ceramic terrarium heater, etc.

Your temp controller should be 2 stage, meaning it will turn on the freezer when it needs to cool, and turn on the heating device when the temp needs to be raised. It will alternate back and forth between the two stages as the temp goes up and down.

For example, suppose you set the controller for 18C, with a plus/minus range of 2C. When the temp rises to 20C, it turns on the freezer until the temp drops to 18C, then it shuts off the freezer. And when the temp drops to 16C, it turns on the heating device until it warms to 18C.

would only using the freezer cause high fluctuations?

 

[MaxStout]

would only using the freezer cause high fluctuations?

You said the freezer's highest temp setting is 2F. You need some way of maintaining higher temps for fermentation.

 

[mac_1103]

What I meant is not fermenting at 2f but rather my freezer's highest temp setting is 2F.

Once you hook up an external controller and set it to a higher temperature, your freezer's internal thermostat becomes irrelevant. It's never going to get that cold.

 

[whoaru99]

Depending location, time of year, etc., there could be enough ambient heat so only cooling control is sufficient.

 

[IslandLizard]

Your temp controller should be 2 stage, meaning it will turn on the freezer when it needs to cool, and turn on the heating device when the temp needs to be raised. It will alternate back and forth between the two stages as the temp goes up and down.

Just a note on using heating devices...
A heating device is not always needed, especially during active fermentation.

As we know, fermentation generates heat, so in most cases only cooling would be needed to keep the temps inside the narrow fermentation range we are aiming for.
That prevents the potential yo-yo effect of cooling/heating/cooling perpetually. IOW, the back and forth (up and down) is not beneficial, and best to be prevented.

Now when a beer is mostly fermented out, or when conditioning, a small heating unit may come in handy, yes. Or just move the fermenter to a somewhat warmer area.
Instead of cooling I've used a small wattage space heater with a built-in fan inside a fermentation fridge to ferment/condition Saisons. Yes, fan connected to a temperature controller.

Now when the fermentation chamber is in an area that's much colder than our targeted fermentation range, a heating device will be needed the keep the temps high enough for fermentation. Usually active chilling would not be needed then.