While you can certainly buy gallons of distilled water at your local supermarket, big-box store, or even drugstore, if you just need a little bit (really, any amount less than a gallon ...
After 1 hour, I had produced about 1 1/4 cup of distilled water. To recreate a gallon jug that you'd find in the supermarket you'd need about 13 hours of distilling time. If you follow these steps ...