Mold in fermentation chamber

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ILMSTMF

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Hello,

My FC is a one-door fridge. Within, there's a freezer compartment on top. I love this style of "old" fridge - allows plenty of room for the height of the FV. I have heating wires taped on the walls too.

Anyway, because of the fluctuating temperatures, mold develops on the surfaces of the FC. Been a long time coming but I got around to cleaning up as much as I could today. I used Clorox bathroom cleaner (containing bleach) to wipe down the FC. Since the FV remains sealed within the FC (except for dry hop additions), would you be worried about mold in the FC? I have a cup of StarSan for the blowoff that remains exposed...but that isn't feeding back in to the FV so...
 
I've had that.

My plan is to put in a vented blowoff system so the fermentation gasses and moisture do not dump into the sealed fridge/freezer (FC). Rather, they will vent to the outside of the FC through a hole and tube/hose.
 
Worried? To what extent?

I'd still keep fermentation chamber as free of mold as is possible. If you are having a issue, then perhaps the fermentation chamber doesn't run often enough to do much of anything. So that might suggest that you don't even need to keep your FV in the FC.

Side note... even though the bubbler jar is StarSan, you might consider adjusting the end of the tube so that it can't suck enough StarSan to make it all the way back and into the FV. I don't care if it is safe enough. I don't want StarSan in my beer.
 
Worried? To what extent?
To the extent of the mold potentially causing adverse effects to the beer.

If you are having a issue, then perhaps the fermentation chamber doesn't run often enough to do much of anything. So that might suggest that you don't even need to keep your FV in the FC.
because of the fluctuating temperatures, mold develops on the surfaces of the FC.
Sorry I didn't make that more clear. The FC also features heating wire. It's common for me to ferment with a target temp as high as 74F. It gets pretty balmy in the FC. There will be an intermittent cool drop to, say, 53F for dry hop contact. What happens then is the fridge compressor kicking on to cool and forming some frost in the freezer compartment. But not cold enough to stay as solid ice so... water will drip from the freezer area. That moisture can / will accumulate at the lowest point in FC. I guess that causes the mold?
A "true" hard cold crash follows that phase. After the beer is transferred from FV, I leave the FC door open to air out. I wipe out the freezer compartment with a towel. But that's not good enough to prevent the mold formation. Any moisture left way lower in FC is still there. A pain to reach but can be done.

Anyway...
 
Your higher FC temps are very near the ideal temps for mold growth. And humid air will give more ideal conditions.

You might consider heating on or in the FV and leaving the FC open during that time or find some way to mitigate the humidity inside the FC. If your airlock or blow off tube exhausts into the FC, then that's probably bringing a fair amount of moisture with it.

You are one of the first I've read that uses the FC to heat the FV. Or at least one of the first that is having a problem that appears more related to the heating. Mold doesn't grow well at cooler temps.

So for the many more that only cool in their FC, that might be why we don't see them posting about mold issues.
 
You might consider heating on or in the FV and leaving the FC open during that time
Huh. Never thought to try that! But what about the heat escaping, wouldn't that be less energy efficient?

You are one of the first I've read that uses the FC to heat the FV
Interesting. When I set it up, my research often pointed to the recommendation of adding a heat source in the FC. I've stuck with it; having pushed late-stage primary as high as 76F. Once the vigorous fermentation has settled down, I ramp target temp up. That's where the heating wire helps.

Sorry to beat this over the head - my question is should the mold be a concern? IE if I don't "obsessively" clean the FC, do I put my beer at risk?
 
Sorry to beat this over the head - my question is should the mold be a concern? IE if I don't "obsessively" clean the FC, do I put my beer at risk?

I think the way to look at this is mold growing in the FC, afaik, can't ever be a good thing re. making beer.
 
I think the way to look at this is mold growing in the FC, afaik, can't ever be a good thing re. making beer.
It would seem obvious, right? I just had to ask, though.

Repeating myself, sorry. It's a ***** to get into every nook of the FC (for cleaning). Add to that the fact that the FV is sealed except for when adding dry hops. My thought about the mold's presence was "probably safe, doesn't pose much of a threat".

I'll give that DampRid a try. I welcome any other suggestions, thanks all.
 
Sorry to beat this over the head - my question is should the mold be a concern? IE if I don't "obsessively" clean the FC, do I put my beer at risk?
Yes it should be a concern.

Mostly because your FC will smell bad. Yeast tends to smell good to me, mold smells.... moldy. And the smell will get stronger and will be unpleasant to most everyone that gets near it whether open or not.

As far as to the beer in your FV, it is a slight risk. Though if it get all over the inside of your FC, it's going to start getting all over your FV. So the slight risk will become more of a risk. But still likely just a slight risk, IMO.

I'm not sure you can quantify it any more than any of the other risks we try to mitigate in beer brewing. Sort of like... If I didn't use a sanitizer, I think I'll still have a good chance of brewing a good beer for the first few times as long as everything is clean. But the longer I go without using a sanitizer, the more risk I'll have for a infection.
 
My plan is to put in a vented blowoff system so the fermentation gasses and moisture do not dump into the sealed fridge/freezer (FC). Rather, they will vent to the outside of the FC through a hole and tube/hose.

I think the best suggestion was in the first response. Get the humidity out of the FC.
Throw a tub of damp rid in there!

Going down the rabbit hole and going off-topic but... Suppose I wanted to capture those fermentation gasses as a supply of "free CO2". Yeah, I'll just search the forums for that; I know it's been discussed. ;-)

Anyway. Much as I'd like to vent outside of the FC, I have limited space where it lives. Especially outside of the FC. I've got a bit of shelf space in the FC above the FV.
Looking like that DampRid might be a good interim solution / good place to start.
 
Suppose I wanted to capture those fermentation gasses as a supply of "free CO2".
Much as I'd like to vent outside of the FC, I have limited space where it lives. Especially outside of the FC.
It's going to be tough to capture the ferm gas without someplace to put a keg, but just to vent them outside the FC only requires enough space for a blow-off bottle.
 
but just to vent them outside the FC only requires enough space for a blow-off bottle.
So, the "good news" is that the fridge was picked from the curb, left for disposal. Whomever had it before me probably used it as a single tap kegerator. There's a hole punched in the door. Since no cooling element is in the door, that's one less thing to worry about breaking (if I needed to bore some more).

Anyway. right now, the blowoff route is like this: FV post -> QD -> tubing (secured by worm clamp) -> cup containing about 1/2 cup of StarSan

Would need to figure out a way to route that outside of the FC, using the existing hole in door.
 
My plan, modeled after other examples on this forum, is to leave the blow off catch can in the FC, but use a closed blow off catch

The large blow off tube still goes from FV to blow off catch can but the catch can is closed container, so to speak, with a much smaller tube from the blow off catch can exiting the FC, since that tube should only carry gas, not krausen.
 
I'll give that DampRid a try. I welcome any other suggestions, thanks all.
[EDIT] I understand the desiccating granular content inside Damprid units doesn't last that long. The granules dissolve and need to be replaced by fresh dry granules (too) often.

IIRC, Eva-Dry units have a built-in heating system that dries out the granules and can last 10 years.
https://www.eva-dry.com/about-eva-dry/faqs/

Once a week, or when needed, I simply use a well absorbing rag and wipe up any condensation in the ferm chamber. I've never seen mold develop.
The rag gets dunked in a little bleach water to deter mold growth too.
 
The large blow off tube still goes from FV to blow off catch can but the catch can is closed container
I love that idea. However, please read on.

If anyone can tolerate my hysteria, here's how I've arrived at my choice for next steps.

Blowoff routed out of FC

Pros
• Gets the CO2 out of the FC (duh)
• Potential to retain / repurpose CO2 (see belo)

Cons
• Lack of technical know-how
• Cost of parts to do the install
• Limited space, no room to put a keg nearby for purging. Could probably put a cup of StarSan atop the fridge but even that has risk of falling off.

Adding moisture control inside FC

Pros
• Easy. Nothing to "install"
• Cost-effective
• Doesn't require much space

Cons
• Cost?
• Have to plug in to outlet (outside of FC) once in a while to dry out

Eva-Dry units have a built-in heating system that dries out the granules and can last 10 years.
At first look, I saw that electric plug and was alarmed by it. What a relief to learn these units operate without need for power.
Going with the E-333. $15+tax on Amazon.
 
fwiw I've been using two pairs of EVA Dry 500s for at least ten years now, cycling the pairs through my 14cf keezer as needed. They hold just over 4 ounces of moisture each when saturated and needing a drying cycle.

As for my fermentation chambers, when I started using fermentation gas to purge my kegs I added 1/4" MFL-MFL bulkheads with JG PTC fittings to the back of both fridges to route the gas to pairs of kegs and have noticed the moisture in the fridges has been significantly reduced as a result. I don't have black mold specs appearing in the freezer compartments any more...

Cheers!
 
I've been using two pairs of EVA Dry 500s for at least ten years now, cycling the pairs through my 14cf keezer
Damnit. Now you got me thinking of putting one in my keezer...
She winds up with a puddle on the floor (of course). Only really notice that when all kegs are out. Though, I'm not seeing any mold / mildew issues in there. I think you all know why - that s**t thrives in the warm.
 
Eva-Dry units

I've been using two pairs of EVA Dry 500s

Another question...
I mentioned earlier in thread but, for reference: After the primary warm phase (on average, 10-14 days starting at 68F and rising to as high as 76F), I'll perform a cool down to prepare for dry hop addition. That's going to 53F. Not cold enough to form solid ice in the freezer compartment. It frosts up and winds up dripping water. Still OK to use the Eva Dry with some "falling droplets"?

Thanks everyone!
 
fwiw, turns out I've been running EVA Dry units longer than I remembered.
12 years ago I posted this thread https://www.homebrewtalk.com/threads/stupidly-effective-keezer-dessicant-hack.335857/

Anyway, the pictures are what I was looking for as they show how I velcro'd small 12VDC fans to the EVA Dry 500 bodies to greatly accelerate their effectivity...

eva_dry_500_1.jpg
eva_dry_500_2.jpg


Cheers!
 
velcro'd small 12VDC fans to the EVA Dry 500 bodies to greatly accelerate their effectivity...
This is terrific. I will need to figure out a way to get power to a fan like that.
I'm using a nice USB powered fan in the keezer. I could do something similar in the FC, perhaps. The wire is thin enough to not make much impact on the seal of the FC. Currently running the temp probe line in from outside of FC the same route. Could do the same for the fan wire. Would just need to secure a power strip atop the FC. Hmmmmm....!
 
@whoaru99 @day_trippr @IslandLizard The Eva-Dry works great! So great, in fact, that I have a new problem LOL, ready for this?

The blowoff hose vents into a large cup filled with maybe 1/3 cup of StarSan. Not even 24' with Eva-Dry in the FC, all the StarSan is out of the cup! I removed it from the FC, for now, and put StarSan back in the cup.

I think the solution would be to figure out a way to put a lid on that cup and route the hose in. I'm not very smart with these sorts of things. I welcome all suggestions, thanks very much!
 
At the moment, not planning to exhaust airlock outside of the FC.

I'm thinking of trying to put a tight layer of foil on top of the cup and punch a hole in it. Run the blowoff through it and hope the Eva-Dry doesn't pick up the StarSan. Worth a try, I suppose.
 
I picked up 2! Next day shipping too :)
A good chance I'll buy another unit or two. One to devote to the keezer per @day_trippr's brilliant suggestion. I'm sure I can find another part of the home to benefit from this product. Will hold off until Prime Day in hopes of an even lower price.

Anyway, new-ish plan. Will hang the Eva-Dry in the FC once the airlock is detached from FV. It will also be employed, especially, when FC is empty / isn't active (cold or hot).
 
A little late to the party here, but this may be what's causing the humidity. I would think you're heating the air instead of directly heating your fermenter.

I'd agree it's probably not the most efficient way to heat the FV. But, even if you more directly heated the FV, being the FC is a relatively small, insulated space, isn't the internal temp of the FC going to heat up anyway from the warm mass of the FV?
 
I'd agree it's probably not the most efficient way to heat the FV. But, even if you more directly heated the FV, being the FC is a relatively small, insulated space, isn't the internal temp of the FC going to heat up anyway from the warm mass of the FV?
Yes, but in order for the wort to get to desired temp, the surrounding air will have to be significantly warmer for a longer period of time.
To the OP, what's your set up look like?
 
but this may be what's causing the humidity. I would think you're heating the air instead of directly heating your fermenter.

I'd agree it's probably not the most efficient way to heat the FV.

I appreciate all who understand my laziness... I would find the effort of wrapping the heat wire around the FV to be more of a hassle each time the FV loads in and out of the FC. Hence, tape them to FC walls and let it go.

Further support to my decision - the hot wires really only activate when I ramp temps up after primary fermentation is done. Recall that I will warm as high as 76F. Since I'm not pushing into the 80s or above, those hot wires don't kick on much or for long periods. However.... yes, in the warm phase, the FC gets balmy... In that same phase, no airlock is attached so, this would probably be a great time to put the Eva-Dry in FC. ;-)
To the OP, what's your set up look like?
I will try to get a photo soon, thanks.
 

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