Beer has had a huge range of alcohol strengths, from Mesopotamia until today, so that statement is nonsensical.
> Just enough to keep it without bacteria.
1% is not enough to keep bacteria from growing in a beer. In general, more alcohol means it will keep longer, but to be truly safe you need to go quite high. This is a pretty complex issue, though.
Beer has had a huge range of alcohol strengths, from Mesopotamia until today, so that statement is nonsensical.
> Just enough to keep it without bacteria.
1% is not enough to keep bacteria from growing in a beer. In general, more alcohol means it will keep longer, but to be truly safe you need to go quite high. This is a pretty complex issue, though.