From
http://homedistiller.org/ Click on Introduction | Legality:
What all this basically comes down to is ...
1. Americans can own a still, but it must be no larger than 1 gallon, and may only be used for water purification or the extraction of essential oils from plants.
2.Dealers/manufacturers of stills in the United States must surrender any address or other info on any customer who buys a still to the BATF, when they request it.(no warrant is required.)
What this means is that anyone who buys a still in America can at any time expect a knock at the door and a man with a badge demanding to see what is being done with the still they bought. How this effects the companies seen advertising 5 gallon stills for use as a water purifier, was not listed, nor is there any info on solar stills. It is probably VERY illegal to import a still too.
If you're trying the angle of making alcohol as a fuel (yes, this is legal!), see Steve Spence's site for all the details.
Whats the cost of doing it right ? Don advises ...
State (varies from $75-$3,150 per year) & a Federal license ($500 per year) plus State & Fed. production taxes. Registration of all supplies, suppliers, formulas (Subject to classification and approval) and label reg. (Subject to classification and approval). More paperwork than money. If you already have a brewery or winery (bonded premisis) an "alternation of premisis" may be obtained to operate a distillery (with the additional license) on site. Well worth the trouble, because there is still room at the top.