Fermentation fridge issues.

[pdickerson76]

Hi all. Like a lot of you I use a mini fridge with a temp controller to hold temps in range. STC-1000 is the unit I use. Set it up for the first time in 5 years. Working great. Brewed a few weeks ago. Outdoor temps were mid60s to mid 70s. Fridge is in the garage and did a good job holding at 68. Checked on it yesterday and temps inside fridge were 64-65. Highs here in Iowa yesterday were 55. I use a 60w light bulb installed in a paint can as a heat source. It's not keeping up when temps dip low at night.

1. What are some of you using as a heat source in your fridge set up? My next purchase will be a ceramic heat source like something in a lizard tank.

2. Will the temp drop in the fermenter fridge effect the brew. Been holding at 67-68 for 9 days. I feel like this shouldn't be a huge problem since it's not within 72 hours of a yeast pitch.

Help!! And TIA.

 

[mkyl428]

Rdwhahb it's fine I regularly keep my fermentation chamber set to 62 degrees ambient, since fermentation creates up to a 10 degree difference in the fermenting beer in my experience

 

[mkyl428]

I don't use a heat source in my fermentation chamber, but you have the right idea, you could also use a heating pad, or they make fermentation belts that fit around your fermenter

 

[smata67]

I hollow out the side of a piece of hard foam insulation to hold the temperature sensor and tape it to the bucket which is then measuring the actual brew fermentation temperature, not the space temperature. For heating, a small fan powered electric heater. I'm using the Ranco single temperature control unit so I have to pick either heating or cooling, not both like the STC. Fact is, the heater rarely even comes on when my garage hits the low 50s, except after 5 days or so when the fermentation slows down and then I'm moving it indoors. You definitely want to do something similar to your sensor with the STC controller to prevent it alternatively cooling and heating unnecessarily.

 

[DVCNick]

I use one of the flexible carboy heat wraps, just rolled up in the corner of the fridge.

If you just have one carboy in there and actually wrap it around as intended, and it is in a fridge, I would think it would keep up with just about any ambient temp you could possibly see.

 

[pdickerson76]

I hollow out the side of a piece of hard foam insulation to hold the temperature sensor and tape it to the bucket which is then measuring the actual brew fermentation temperature, not the space temperature. For heating, a small fan powered electric heater. I'm using the Ranco single temperature control unit so I have to pick either heating or cooling, not both like the STC. Fact is, the heater rarely even comes on when my garage hits the low 50s, except after 5 days or so when the fermentation slows down and then I'm moving it indoors. You definitely want to do something similar to your sensor with the STC controller to prevent it alternatively cooling and heating unnecessarily.

I have the temp probe taped to the carboy with electrical tape right now, not actually tapping the probe but the cord it's attached to. Do you have a pic of this fan that you use that you could share with me, or a link to it?

 

[pdickerson76]

I use one of the flexible carboy heat wraps, just rolled up in the corner of the fridge.

If you just have one carboy in there and actually wrap it around as intended, and it is in a fridge, I would think it would keep up with just about any ambient temp you could possibly see.

What temp ranges do those heat warms usually run? My gf has an extra heat mat for starting seedlings and that runs mid 70s to mid 80s.

 

[pdickerson76]

I don't use a heat source in my fermentation chamber, but you have the right idea, you could also use a heating pad, or they make fermentation belts that fit around your fermenter

I'm guessing that you don't have to worry about lower ambient temperatures then?

 

[DVCNick]

What temp ranges do those heat warms usually run? My gf has an extra heat mat for starting seedlings and that runs mid 70s to mid 80s.

These are the ones I have:

https://www.amazon.com/gp/product/B0719WSY3B/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
The surface temp will get to roughly 120-140F depending on ambient.
I've maintained temps as high as mid 80's without it running close to all the time.

It runs a little more when I have two carboys in the fridge, fermentation isn't active, and the ambient in my house is in the low 60's, but still, the duty cycle then is not even remotely close to all the time/it has no problem keeping up.

 

[pdickerson76]

These are the ones I have:

https://www.amazon.com/gp/product/B0719WSY3B/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
The surface temp will get to roughly 120-140F depending on ambient.
I've maintained temps as high as mid 80's without it running close to all the time.

It runs a little more when I have two carboys in the fridge, fermentation isn't active, and the ambient in my house is in the low 60's, but still, the duty cycle then is not even remotely close to all the time/it has no problem keeping up.

Do you have this hooked to a temperature controller that cycles heat and cooling, oj just plugged into the wall?

 

[DVCNick]

Just plugged into the wall would have it running all the time and you'd be way too hot in short order... definitely don't want that.
I have it plugged into a dual stage temp controller, but with my 1 degree tolerance setting, it would actively alternate heat and cool indefinitely if I had both plugged in at once. Both my heat and cool will overshoot by more than 1 degree after the controller turns them off. So what I actually do is just pay enough attention to manually swap the heat and cool being active, as needed.

In the winter, that means I have the cool plugged in until the active fermentation is tapering off, and then switch to the heat. In the summer I don't need the heater at all unless it is for a saison or something that needs to be held in the mid 80's or higher.

 

[eric19312]

I use a 60w ceramic reptile bulb on a ceramic base for heat in my upright freezer in an mainly unheated garage. The garage is under living space so gets some heat in dead of winter probably not below about 50F.

That said last winter I brewed a kveik in there at 95F (not maxed) so was easily holding 50F over ambient. Freezer probably better insulated than a dorm fridge.

I do run a fan in the chamber all the time.

 

[mkyl428]

I'm guessing that you don't have to worry about lower ambient temperatures then?

No, but my fermentation chamber is inside in my laundry room. As long as the ambient temps in the chamber aren't lower than 58-59F you will be fine with most yeasts