οἶνος does refer to wine (whether fermented or not). The issue comes with context and other words (like γλεῦκος, οἶνος νέος ).
γλεῦκος, for example, is "new wine" (earlier in the fermentation process while prior to the wine loosing much of its sweetness). In Acts bystanders accused the disciples of being drunk on γλεῦκος.
οἶνος νέος is "new wine", or wine that has neared the end of the fermentation process. You would not put οἶνος νέος in old wine skins because this would cause the wineskins to burst.
κράσθαι is the practice of mixing wine (alcohol) with water (considered more hospitable drink to offer guests than water, also done as it was believed to make water safer, particularly in cities like Jerusalem where cisterns may be relied upon rather than wells).
