I received a 5 gallon carboy that I want to use but it has some crud in the curve of the bottle. What's the best way to clean this off?

4 Answers 4


I've used PBW and One Step to do this, but:

  1. They're both pretty expensive. You either need to make five gallons of solution or figure out a way to get the solution against the crud without filling the carboy.
  2. When I'm cleaning a carboy, I'm almost always not doing anything else brewing-related, so I can't reuse the solution.

I have recently fallen back on Charlie Papazian's trick of an overnight soak with a half-cup of bleach in 5 gallons of water. I use warm water, but it's room temp by the next day, naturally. I siphon off until the water level is just above the krausen ring, then go at it with a carboy brush. That way, the crud I remove is carried away by the water. Works brilliantly.

And it's dead cheap.

  • I though that bleach will break down with heat. Shouldn't you be using cold water?
    – DrDJ
    Commented Nov 2, 2010 at 18:37
  • Not really sure if I care if the bleach breaks down. I just want the gunk off the carboy, and this seems to work. Using cold water might be more advisable for sanitizing with bleach, but this is about cleaning. Commented Nov 13, 2010 at 15:33

PBW, hot water and if neccessary, a carboy brush. They are made with wire similar to a coat hanger so you bend it in the middle of the bristles at a 90 degree angle and reach the bend that you talking about. I would throw in the hot water and PBW and wait twenty minutes, the crud will most likely just flake off. You can always rub it with the brush to be sure but this will definitely get that stuff off. PBW is magic.

  • 1
    One Step sanitzer works well, too, it just has to soak a little longer. 1 Tbsp per gallon, fill the carboy to the top with hot water. It will dissolve a seemingly rock-hard krausen ring in about an hour.
    – JackSmith
    Commented Aug 6, 2010 at 16:38

Bar keepers friend is pretty cheap to use as a 5-6 gallon soak. Just use a few tablespoons in warm water and fill up the carboy. An overnight soak and you're good to go.

  • +1 for Bar Keeper's Friend - that stuff is great!
    – Jim
    Commented Aug 26, 2010 at 17:27

Try Proxiclean, it's something we use at the winery to clean tanks and fermenting bins. It's basically a less gnarly form of caustic (PBW). In a nutshell, it's a powdered version of that blue crap Billy Mayes used to push on TV infomercials-- an oxidizing cleaner. But a proxy soak for 24 hours will basically put a shine on a turd. I get it from the Vintner's Vault in Paso Robles. They have a website... lemme see... http://www.thevintnervault.com/

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