Vault? Nah!
Native yeast are always going to be present in the grape must. It comes from the field and is already on the grapes.
If you utilize the same strain of yeast often, that strain will become the "native yeast" of your wine room, meaning, if you don't add any yeast and you just leave your must exposed to the air, your native yeast, and any native yeast already present in the must will fight it out to get the chance to ferment your batch. Some yeast strains can co-ferment together; some will kill the other to have the prize of fermenting your must. Either way, your must WILL ferment.
(If your wine room is your kitchen and you make bread often, guess what the native yeast could be in your kitchen area - bread yeast. This is not a problem as long as you always pitch a good, health packetized yeast.)
Where yeast are concerned, those coming directly from packets are in a much greater quantity and concentration than your native yeast, so if you do add your packeted yeast, it is going to be the predominate yeast, and before any native yeast can take hold, they will already be plenteous enough to overwhelm and do the fermentation. That is assuming you don't leave the must exposed for several days before adding your packeted yeast. Doing so will give the native yeast time enough to become established in your must. This is one of the good reasons for adding sulfites before fermentation of fresh/frozen grapes, if any waiting period is done before starting fermentation.
The bacteria for making vinegar is another story. If they are present, yeast fermentation can go on as usual without a problem. However, those bacteria can get into the must right away and eventually start growing and do their dastardly deed at a much later time. This can be the cause when one opens a bottle of wine, which should still be good, and finds it has turned to vinegar.
Of course this is one reason why after fermentation, one needs to keep the free SO2 levels up where they belong, which should provide protection against such bacteria. In the end, one's best bet is to not tempt fate and never mix wine making and vinegar making in or near each other.
Would vinegar bacteria be able to travel, ie. attach to clothing, from a room in the garage to a wine making room in the house? I'd like to try to make vinegar from homemade wine but if I risk the chance of contaminating my property with vinegar bacteria forever, guess were not having vinegar.
Thanks!
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