Want to make frozen yogurt that TASTES like yogurt

I used to love frozen yogurt - not the low-fat ice cream substitute sold in stores today, but the old-fashioned type that had the sour yogurt-like taste (lactic acid?). I tried this recipe last night and it was pretty good, but it basically tasted like low-fat ice cream, not yogurt. Anyone have other recipes I might try, or suggestions for modifying this one?