[2019] How do you store purified water?

You should be able to put a 'beverage zone' on the barrel or a 'custom' zone with the beverage selected. If the water is already in a zone, say an 'all' zone, they won't think it needs to be moved. If you can't get it working, it could be a bug, in which case I'd appreciate you sending me your save folder so I can take a look. :)