It is possible to ferment fruit juice in a jar in your closet. Leave the jar open for a few days, or dunk your feet in it to get the natural yeast working. Then let it sit for a couple of months.
The result will be a disgusting alcoholic sludge that will PROBABLY not kill you.
If it does kill you, I claim no responsibility.
However, you may wish to thank me when you discover that there is no 21% sales tax, no rent payment and no riot police in the afterlife.
Plus, it’ll be better than most Spanish beers.
Other tips for life and austerity at Pro Tips.