Foggy Carboys

Hello homebrewers!

I have recently encountered something I have never experience before and was hoping for some advice.

I clean my 6.5, 6, and 5 gallon carboys by using one of the long bendable brushes and scrubbing the heck out of the insides with dish soap and water. Then I clean the outside with the same mixture. I rinse the soap out with clean tap water until the water runs clear (no more suds). Then I invert the carboy on one of those blue carboy drainers over a towel. It's the same process I have used for quite some time.

However, lately I have noticed that my carboys have been getting foggy or misty on the inside and even if I let sit inverted for days this fogginess doesn't go away. I don't want to put them away in this state because I'm worried about mold growth. Can anybody help?

You probably have some sort of film developing on the glass, maybe from hard water, or your soap, or some combination of other factors. Get yourself some of this, and soak them in it.



If that doesn't work, you may want to try some Muriatic Acid.

It sounds to me like it's moisture trapped in the carboy. Set them upright for a couple of days with a loose aluminum foil "cap" and the moisture should evaporate.

I'm assuming your carboy has dried and you are not just looking at condensation. I had a similar experience when I let some water/straight A cleaner soak overnight. It looked exactly like the haze my dishes were accumulating after running thru the dishwasher. I did some research and found that many thought it was a hard water issue. The haze is left over minerals when the water evaporated. Some of these minerals were in my water and the Straight A seemed to react poorly with my water and contribute even more. My initial solution to remove the haze was a vinegar/water soak.....yes, I *****ed my carboy. This took a while to rinse the vinegar smell though, but it did remove the haze. I had to do this until all my straight A cleaner was gone.

I then realized that Star San is also an acid...tried the soak with a typical sanitizing amount and all haze was removed.

I switched to Brew Clean and no longer get the haze.

Sometimes I have my carboys drying for days and the condensation never seems to disappear. Now I just let it "dry" upside down for a day then put it away. I store them on their side with a piece of an old t-shirts held around the mouth with a rubber band. It eventually dries completely. The shirt just keeps out the dust/dirt but allows the carboy to breathe.

Good Luck

Question: Glass or plastic carboys?

You're not supposed to use the brushes on plastic bottles because they WILL scratch. A good soak in PBW will dissolve anything in there, no brush necessary.

You can use regular vinegar with some water, it is milder but if you let it soak you will get all mineral deposits out. I use this on my coffeemaker pot for example and it looks like new. Vinegar is mildly acidic.

rappyfreak said:

You can use regular vinegar with some water, it is milder but if you let it soak you will get all mineral deposits out. I use this on my coffeemaker pot for example and it looks like new. Vinegar is mildly acidic.

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Vinegar worked for me as well.

After a hasty clean followed by almost 5 years sitting around empty, my better bottles and glass carboys were in bad shape. You couldn't see through them. Completely opaque. I rinsed them, washed them with Starsan, they were still cloudy and nasty looking.

Part of it was that when I was moving out of the house I was in, I was in a rush and didn't take the time I should have... and now I was paying for it. The thing that finally made them look as good as new was...

A few ounces of vinegar shaken around the inside and rubbed over the outside... keeping the surfaces wet for about an hour. And then Dawn Dishwashing liquid... in the same concentration you'd use for REALLY dirty grimey dishes. I actually used a sponge along the outside of the carboys with about a 50/50 detergent/water solution and let it sit for about 15 minutes before rinsing off.

It cut the grime and the mineral deposits. My BB's now sparkle like new.

Thanks everyone.

It was condensation so I think I'll try that T-shirt trick but I also found that if you rinse with cold water then it reduces the condensation.

And when I do start getting sediment on the carboys, now I'll know what to do!

Thanks again!

I've had that fog. It's nothing to worry about. I usually do a good cleaning and just leave the carboys to dry. I always do a light rinse and sanitize before I fill them anyway, so it's really not concerning to me should they try to grow anything inside.

smf said:

The shirt just keeps out the dust/dirt but allows the carboy to breathe.

Good Luck

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Carboys need to breathe? Who Knew? The things you learn on this site are amazing!

+1 to using white vinegar. A healthy mix with HOT water and let it soak for awhile works for me, too.

Another reason for the dish soap however is that dust particles can scratch plastic, especially when rubbed in. So using some dish soap on the worst of your carboys will help encapsulate and lubricate the dust particles, reducing the risk of microscopic scratches which could harbor bacteria.

The vinegar works. I recommend that as well. But first use dish soap to do the heavy cleaning.