Stainless Steel Tank aging issues

[KayThrasher]

I am part of a winemaking club - we currently are aging our wine in both 1100 liter stainless tanks and several wooden barrels. The concern is the SS tanks - if we leave enough headroom on the lid for expansion and contraction due to temperature changes, the top of the wine is starting to form mold. Dropping the lid to the top of the wine means that it will leak out at the vent or around the seal and attracts bugs (and we want to keep our landlord happy!). Are there any suggestions of a floating cover of some sort that can be used? I'm thinking of bubble wrap or styrofoam that would cover most of the top and reduce the amount of wine exposed.

Any suggestions on a material to use that is compatible with wine? I don't want to impart plastic flavors...

 

[balatonwine]

If your wine if forming mold in the head space, then I would suspect you have issues with the wine that is probably independent of the container material.

Or your seals are leaking. Put an airlock on the tank to monitor the seals. Or do a seal test:



Or use the glove method:



Also, if your seals are good, are you injecting a gas like Argon or Nitrogen into the head space? If not, you should consider it.

 

[KayThrasher]

Great suggestions! We will definitely look into the gasket leaking, we've had some issues in the past but thought we had it solved. The glove idea is also a possibility.

Thanks for your help!