Winemaking is relatively easy, until something goes wrong!  Most beginning home winemakers who follow the instructions that come with wine kits and bottle their wine after 28 days will avoid most of the problems.  Intermediate home winemakers who make wine from grapes, fail to thoroughly clean all of the equipment that touches their wine, bulk age their wine for extended periods, use oak barrels and even those who use variable volume stainless steel tanks will run into a problem sooner or later.  The preferred method is to learn about wine flaws and faults and therefore avoid them. 

I use variable volume stainless steel tanks and oak chips to avoid the maintenance problems associated with oak barrels.  However I had a problem with these tanks (shown on my home page).  The tanks came with bubblers that have a glass marble seal that allows CO₂ to escape when using the tank as a primary fermenter.  I purged the oxygen in the tank with CO₂ and sealed up the tank.  I sampled the wine once or twice each month while the wine was bulk aging and I determined that the bubbler allowed air to enter the tank and oxidize my wine.  I bought a solid silicone bung to replace the bubbler to address this issue.