When planning a new winery for Château Maris in southern France's Languedoc region, Robert Eden looked at natural building materials such as stone, rammed earth and even straw. What he ended up choosing had the potential, at least among certain crowds, to elicit quips: hemp. But it's no joke: The new Maris winery is built almost entirely from large, sturdy "bricks" of organic hemp straw. Those bricks not only reduce carbon emissions from construction, but also capture carbon dioxide from their surroundings. Wine Spectator's Dana Nigro reports.