The highest degree of pure natural fermented red wine is 15 degree, because beyond this degree, the yeast is killed and the fermentation stops.

There is a kind of wine, called Du Jia wine. In the brewing process, the fermentation is artificially stopped by adding strong brandy. The degree of this wine can reach more than 20 degrees. This type of wine is famous in the world, such as Porto wine in Portugal and Sherry in Spain.

Homemade wine usually does not use artificial addition of spirits. Generally, it is pure fermented wine, with the highest degree 15 degree, which is not very high. Maybe it's because the homemade wine is sweeter and better, but it's stronger all of a sudden.