18 replies to this topic

[davelew]

I brewed a tripel about two weeks ago, and when I was making the starter, I discovered some black mold in the growler I use for starters. I cleaned the growler, then half filled it with water and microwaved it for 10 minutes, then went through my usual Iodophor routine, and I haven't had any problems. Today, I racked the tripel into secondary. When I took my glass secondary fermenter off the shelf and took the stopper out, there was a big "WHOOSH" of air, so I know it was sealed, and probably sealed when it was summer and the air was warmer and less dense. Then I saw that the plastic stopper, where it was inside the carboy, was black with mold.So, two of the last three glass fermenters that I've taken off my brewing rack have had mold problems. I store my fermenters sealed, so it's strange that two of them have mold.Has anybody had black mildew or mold in their brewery? Any suggestions on what to do about it, beyond just keeping things dry?

[ANUSTART]

Why store them sealed? The lack of airflow might be causing the mold. I got a bunch of carboys in the garage that I store with no lid at all. Worst that happens is they get a little dust inside.

[SchwanzBrewer]

Why store them sealed? The lack of airflow might be causing the mold. I got a bunch of carboys in the garage that I store with no lid at all. Worst that happens is they get a little dust inside.

I would add, store them upside down if possible so they drain all the moisture, but that might require some handy work.Cheers,Rich

[pete maz]

Either that, or store them sealed with a dash of Star San. Just enough to splash around and coat the inside. I got tired of having to make sure everything was dry so that mold wouldn't grow, but SS ended those issues.

[realbeerguy]

I would add, store them upside down if possible so they drain all the moisture, but that might require some handy work.Cheers,Rich

Store them open & upright. The ones I stored upside-down in the carboy holders always get moisture trapped. Moist environment = mold.

[stellarbrew]

My guess is that you you have a strong population of mold spores floating in the air wherever you brew. Too much moisture in the air, combined with inadequate ventilation might be the root cause. Maybe check your HVAC ducts for mold, too?

[Thirsty]

Any suggestions on what to do about it, beyond just keeping things dry?

Or you could buy one of these machines! www.bio-cascade.com I sell these to large manufacturers and garages with horrific odor and pollution issues, but the smallest machine would work well in a brewery.

[Cliff Claven]

I fold a paper towel a couple of time and affix it to the carboy with a rubber band. Allows moister to vent but keeps bugs and dust out.Don't know if it will help you or not.

[davelew]

Why store them sealed? The lack of airflow might be causing the mold. I got a bunch of carboys in the garage that I store with no lid at all. Worst that happens is they get a little dust inside.

I store them sealed so that they inside stays free from dust and the microbes carried by dust.I suppose I should make something like Pasteur's swan-necked flasks to keep dust out while still letting water evaporate, maybe a dry S-shaped airlock with a screenm to keep insects and spiders out.Edit: or I could do what Cliff just said, which would do the same thing with less work.

[ANUSTART]

I store them sealed so that they inside stays free from dust and the microbes carried by dust.I suppose I should make something like Pasteur's swan-necked flasks to keep dust out while still letting water evaporate, maybe a dry S-shaped airlock with a screenm to keep insects and spiders out.Edit: or I could do what Cliff just said, which would do the same thing with less work.

Yea, I like the paper towel idea too, but what's so wrong with the dust and microbes during storage? I'm assuming you're rinsing and sanitizing between storage and racking.

[zymot]

Anything glass gets open air treatment. Dust is not a big thing, it rinses off easy. I do not view it as a big threat anyway. Stoppering up a jar is asking for more trouble than a little bit of dust.For glass, I give things the bleach treatment. Good healthy exposure to bleach, then rinse with tap water. All you have left to do is sanatize against water ever nasties might be in your rinse water (i.e. tap) with an exposure to Iodophore & water solution.zymot

[davelew]

what's so wrong with the dust and microbes during storage? I'm assuming you're rinsing and sanitizing between storage and racking.

I'm not confident that I get 100% of the dust when I rinse. Plus, sometimes dust combines with water to form a sticky sludge, and then I need to break out the carboy brush and scrub, and I hate scrubbing.(I store my carboys in a 90 year old unfinished basement, and there's a fair amount of dust as well as a few areas that are open to bare dirt where the utility lines come into the basement)

[CaptRon]

I store my carboys upside down in their boxes with a paper towel at the bottom of the box for absorbtion. I wouldn't seal them up because moisture from condensation that can't escape will equal mold eventually. And my garage that I store my brewing equipment in is probably as dusty as your basement + cobwebs.

[3rd party JKor]

Either that, or store them sealed with a dash of Star San. Just enough to splash around and coat the inside. I got tired of having to make sure everything was dry so that mold wouldn't grow, but SS ended those issues.

+1With the few carboys I have remaining, I put a little Star San on the bottom and cap it with a piece of foil. I've only run into issues with mold when I haven't been careful about cleaning, or just simply didn't clean something and left it out. The problem your having sounds a little different. The rubber stopper is one thing. They can be porous and will provide a place for mold to grow. The growler is a little different. I'm kind of surprised you'd get mold in a clean sealed growler. Had it been well cleaned, or just rinsed, before you put it away last?

[MakeMeHoppy]

I try to dry them good before storage. I have noticed I get much some condensation storing upside down. Now I leave it upright over night to dry and when I see no signs of moisture I store in the original box or throw a dry towel over it. This seems stuff from getting in the bottle and also limits light which seems to allow stuff to grow.

[BrewerGeorge]

I store wet with starsan. I put a double-fold of plastic wrap (sanitized) on top loosely then push the bung into the wrap to make a seal. I don't use glass carboys much, and I've had them remain perfect after over a year of storage in this condition.

[denny]

I would add, store them upside down if possible so they drain all the moisture, but that might require some handy work.Cheers,Rich

I stuff a wadded up paper towel in the neck of mine. Lets them breathe and the towel absorbs any moisture inside.

[SchwanzBrewer]

I fill mine with oxyclean and water and let them soak from the previous use, then I scrub and wash with starsan, I store mine in the garage, open, with starsan in them. I need more carboys so I can brew more often.Cheers,Rich

[gnef]

is all this in a basement? If so, do you have a dehumidifier for your basement to keep the relative humidity down?When I first bought my house, it had a partial basement, and the basement had a moldy stench to it. I put in a dehumidifier, and it went away.Another option is to put a True HEPA filter in your brewing area, and keep it on low all the time. That should help to keep the mold down as well.