Fri Mar 31, 2006 6:25 am
I don't know about how concerned I'd be with the mold infecting fermenters, etc, if you'll be doing ales in the fridge. But, I do know a little about mold.
If you want to completely get rid of all traces of mold (good luck), it's a tremendous amount of work. And, by the way, if you can smell it - it's still there. Even if you can't see it (even if you can't smell it!), it might still be there. Mold is different that your standard viral or bacterial cleaning. Spore-generating molds can encapsulate their offspring in spores which can withstand all but the most severe conditions. Bleach, sanitizers, sometimes even acids, are not a problem for this robust little organism.
There are a few commercially available cleansers specifically for mold (like Spor-Klenz, for example). But these mold cleansers are VERY hard on your equipment. Weekly cleaning with this stuff will eat through 316L SS with no problem whatsoever. I work in a pharmaceutical facility and approximately every year or so we have to replace stainless steel wall coverings and equipment in critical areas because we clean regularly with sporicides.
That being said, it can be done. I'd start by disassembling everything you can dissassemble (interior and exterior panels, ducts, escutcheons, hinges, you should be able to see the windings on the compressor motor when your done and be able to tell what color every wire and connection is in the thing). And wipe/scrub every surface with some sort of sporicide (it's my understanding that these are only surface acting 0 i.e. if it the mold/spores doesn't physically come in contact with the rag with cleanser on it, you haven't done anything. Aerosols or spray-n-forget stuff won't cut it.). Be sure to get every ariflow surface you can find. Example, the fridge has a blower on it, clean the blower and any ducting to and from the fridge interior. Wipe/scrub, rinse with a leave-on sanitizer (like Star San). May want to repeat this at least once.
O.k. that was a good discussion on how to clean (may not have needed that I'm guessing). But my overall suggestion is that you really don't need to do all that. However, you DO need to be exceedingly dilligent in your cleaning and sealing of your fermenter before it goes into the fridge. If you're doing carboys (or any fermenter for that matter), consider using a large plastic bag that you've sanitized (or are reasonably confident is "clean") and bag the whole damn thing before putting it in the fridge. Leave some extra slack so the CO2 has somewhere to go (or periodically vent the bag, or rig up some sort of two-airlock-in-series kind of thing to give you some added confidence that any mold laden air won't make it back to the fermention). Just be sure you seal and double-seal (if you can) every possible source for the mold to make it's way into the fermentor. Remember, with a fridge like that you're constantly bathing the fermenter in a stream of mold-laden air (possibly something like 10^3 or 10^4 times more mold than ambient conditions - depending on how much mold you've actually got thriving in your giant petri dish).
Same story as always though. Clean your stuff really well, seal it really well. As long as you're controlling the tem at that point, I wouldn't worry too much about the mold in the fridge. Technically mold is damn near everywhere and we eat and breath the stuff damn near 24/7. It can certainly infect beer (I've had it happen to me and, other than the pretty colors and actually quite aesthetic floral arrangement it made, was a terrible incident), but don't stress over it too much.
Oh, and hang and air freshener in the fridge so you won't have to smell the mold so much.
On the SS pitting... stainless steel naturally passivates (hence the "stainless" part) in most conditions. The issue with using chlorine based cleaners... it's not the cleaners that cause the pitting - it's the process for cleaning that causes the pitting. For example, spray straight bleach on stainless, scrub, rinse REALLY well, dry - no problem, no pits. The problem is allowing the chlorine to sit on the stainless and allow the chlorine solution to react with and penetrate the oxide layer on the surface. Once that oxide layer is penetrated (and the subsurface material prevented from oxygen contact - ie reforming the oxide layer) it corrodes just like standard ferrous steel. The reason we see pits is that the oxide layer is penetrated in a small area and the galvanic couple says to itself "there's low resistance path to electron transfer over there, why should I do any thing anywhere else?" and beings to actively corrode only where the outside layer is penetrated and very locally. Over time, the pit grows, but it doesn't corrode uniformly across the surface like regular steel, except in very special conditions.
So what to do? Clean the hell out of it with a nice (non-chlorine, just in case - be nice to your stainless, it'll be nice to you) sanitizer. Get in and scrub the pits (like with a toothbrush or something that you know is getting into the pit and removing any surface debri). Rinse rinse rinse. Dry real well, allow to air dry with plenty of circulation, and you're done. Aesthetically it's not great, but it's not going to hurt anything or continue corroding appreciably. That's why it's an "under the bar" fridge and not a "replace the TV" fridge.
Anyway, probably WAY more than you wanted to know. Ask my wife, I can talk for hours about absolutely nothing. Hope it helps in some small way. And good luck.
