Homemade wine can spoil.

Because it is difficult to filter and sterilize homemade wines, which are necessary for winemaking, they can easily expire. The growth of white hairs in homemade wine and the odor of wine indicate that the wine has been infected by stray bacteria.　In general, the shelf life of homemade wine is relatively short because the process of home brewing wine is simple, and the temperature, humidity and sealing degree of the storage environment are not well controlled, so the shelf life of homemade wine is mostly two months.

Homemade wine should be consumed within a year, as the taste will fade over time, but it will not jeopardize your health. It is better to store bottles diagonally, with corks swollen with moisture and impermeable to avoid contact with air and oxidation. It is better to place the wine at a temperature of about 0℃ for storage.

Expanded Information

Because homebrewed wine produces carbon dioxide during the fermentation process, if the winemaking container is sealed, the carbon dioxide can not be discharged will lead to the phenomenon of blowing up the bottle. For this reason, priority should be given to the use of steel and food-grade plastic containers, it is best to choose a container with a large mouth, fill the grapes do not fill, leave a gap in the mouth of the bottle or use 8 layers of gauze to seal. The wine should be completely separated from the yeast at the end of fermentation to prevent fermentation from blowing up the bottle during storage.

When the home-brewed wine appears cloudy, loses its light or takes on an oily, iridescent color, etc., and smells of acetic acid, nail polish, mildew, rats, and other off-flavors, you can basically tell that the wine has gone bad and is no longer suitable for drinking.

Source of reference? People's Daily Online - Don't seal containers for home-brewed wine