The Slow Food Movement has finally hit bars--and margarita mix is quickly going the way of high-fructose corn syrup. Along with bottles of Tanqueray and Grey Goose, bartenders are lining up pitchers of freshly squeezed lime, lemon, and orange juices. But pure juice is just a small taste of what the bar-fresh movement has turned up. Much more interesting--and complicated--is the hand-crafted tonic water that's beginning to replace Schweppes and Canada Dry on the soda gun. Bars are now concocting their own brews that, in unique proportions, blend tonic water's basic elements: quinine powder (the bark of the cinchona tree, which has anti-malarial qualities), lemongrass, lime, sugar, and soda water. Locally, you can find homemade varieties at Larimer Square's TAG and Berkeley's Shazz Cafe and Bar. At the downtown eatery, sidle up to the sleek, dark bar, and you'll find beakers full of tan powder. This mixture of quinine bark, sugar, lemongrass and lime powders, sugar, and citric acid is stirred into bubbly water for a dry, slightly acidic beverage that marries well with fruity gin. At Shazz, the bar takes a more conventional approach to crafting tonic water, creating a concentrate of orange, lemon, and lime juices, as well as allspice, cinchona bark, and lemongrass. This syrupy liquid is combined with agave syrup and carbonated water for a slightly sweet and aromatic soda. TAG, 1441 Larimer St., 303-996-9985; Shazz Cafe and Bar,  4262 Lowell Blvd., 303-477-1407.