Stop mold in fermentation chest freezer?

[sjfischr]

Hi all,

I have a Magic Chef chest freezer with a dual-stage temperature controller for fermentation. Despite my best efforts to keep it clean between uses, it gets moldy towards the end of fermentation. Not a huge deal since the carboy is sealed, but I use a ported better bottle to facilitate closed transfers, and if the spigot gets moldy, well then it makes it pretty hard to work with.

Chest Freezer:

Interior:

Measuring the interior with a thermometer, it reads 65 degrees with typically 99% humidity. Perfect conditions for mold.

Any ideas to prevent mold?

Thanks!

 

[ESBrewer]

I don't know exactly, but if it's virtually airtight so you could try to dry the air in the beginning (maybe some silica gel to the bottom) and then prevent opening it during the fermentation. This way no extra humidity should get in there. Of course it will be difficult to see if there is krausen etc. If you need to open it frequently, it may be difficult to keep it dry cause new humid air will enter each time the lid is opened and then it condenses on all the cold surfaces so you may need to dry it with a cloth and even then it may be difficult to keep it dry enough.

 

[Beholder]

For ales, I use a room dehumidifier like this one https://www.walmart.com/ip/Dehumidi...7840&wl11=online&wl12=947977064&wl13=&veh=sem

It doesn’t work for lower temps for lagers and serving, so for that I use something like https://www.amazon.com/dp/B000H0XFC...t=&hvlocphy=9011742&hvtargid=pla-175638461812

While the first has a fan built in, the second is helped by a small fan to recirculate.

 

[Brewdog333]

Try lining the walls with craft paper to make a moisture barrier. The same reason that house insulation has craft paper on one side. Just an idea from a construction guy

 

[Sparkncode]

I dont see paper doing much given plastic walls.

I would go with silica gel as you can dry it in the oven for reuse. Nice low tech and simple. I haven't had issues yet in my fridge based fermentation chamber yet.

The air was really dry on my last two batches but it probably depends on your enviroment. I may get issues at different times of the year and if I do I'm planning on using silica gel.

I have been doing ales. If you are doing largers than warming up for the d-rest then i guess that could contribute to moisture issues too.

 

[ancientmariner52]

Do you have any sort of cap on your spigot? A short piece of tubing with a sawed-off stainless steel bolt would keep mold out. Or wrap it with foil or cling film. However, if you get the humidity down the problem will go away.

 

[opercularia]

The CO2 coming from your airlock will be saturated with moisture - it's unavoidable in a fermentation chamber. This has worked for me and many others. I haven't had any mold since I started using them in my ferm chamber and keezer

 

[greyghost]

The CO2 coming from your airlock will be saturated with moisture - it's unavoidable in a fermentation chamber. This has worked for me and many others. I haven't had any mold since I started using them in my ferm chamber and keezer

+1

 

[Hop]

When I lived in New England, I kept an extra bucket of the cheap calcium chloride used to melt ice on your driveway around. Scoop some of that into a bowl and it absorbs all the moisture. You'll know when to replace it when it's basically jelly.

In California those buckets don't exist and it's dry here, so I just rotate out bath towels every few days. They're decent for soaking up moisture.

 

[day_trippr]

The thing about chest freezers is they're designed to freeze. When the compressor is running the chilled liner temperature goes far below the freezing point of water, so moisture in the cabinet will freeze to the walls, and exterior air will find its way into the cabinet to keep the air pressure equalized, bringing in more moisture. Then, when the compressor shuts down and the cabinet temperature rises, the frozen moisture thaws and drips to the floor.

Repeat frequently and you end up with a swamp. bt/dt...

https://www.homebrewtalk.com/forum/threads/stupidly-effective-keezer-dessicant-hack.335857/
[lost pics restored a few posts in]

Cheers!