Thank you guys for your quick reply.
I don't have anything else - chemicals, extra buckets or 'tools' , except the bucket with the lid, the must

and the package of yeast. I'm not planning to get 'to deep' into this wine making, at least not for now, because I live in an apartment building.

Is just that I ended up with so much must, that I can't drink it all, and I don't want to loose it or make it vinegar.

The girl from the front desk where I bought the must and the container from, made it sound so easy: put this package - the yeast, let it sit for 9 months, and that's it - the wine is ready.

Suuuuuuuure. If it would have been that easy, everyone would have been making wine.
Anyway, I just needed the 'easy version' of how to not loose this must.
I appreciate it.